kong.service: Control process exited, code=exited status=4

Summary
Installed kong as a deb package in ubuntu 18.04 but service cant start
Steps To Reproduce

Install as a dep package
Run database migrations
Execute kong start command
curling port 8001 yields not results

Additional Details & Logs

Kong version 2.0.0
Kong debug-level startup logs ($ systemctl status kong)
Kong error logs: session closed for user root
Operating system Ubuntu 18.04

Can you provide more info here?
Which database are you running and what's in the kong.conf?
Have you tried the DB-less mode?

Am using Postgres database, Here my kong conf
# -----------------------
# Kong configuration file
# -----------------------
#
# The commented-out settings shown in this file represent the default values.
#
# This file is read when `kong start` or `kong prepare` are used. Kong
# generates the Nginx configuration with the settings specified in this file.
#
# All environment variables prefixed with `KONG_` and capitalized will override
# the settings specified in this file.
# Example:
#   `log_level` setting -> `KONG_LOG_LEVEL` env variable
#
# Boolean values can be specified as `on`/`off` or `true`/`false`.
# Lists must be specified as comma-separated strings.
#
# All comments in this file can be removed safely, including the
# commented-out properties.
# You can verify the integrity of your settings with `kong check <conf>`.

#------------------------------------------------------------------------------
# GENERAL
#------------------------------------------------------------------------------

#prefix = /usr/local/kong/       # Working directory. Equivalent to Nginx's
                                 # prefix path, containing temporary files
                                 # and logs.
                                 # Each Kong process must have a separate
                                 # working directory.

#log_level = notice              # Log level of the Nginx server. Logs are
                                 # found at `<prefix>/logs/error.log`.

# See http://nginx.org/en/docs/ngx_core_module.html#error_log for a list
# of accepted values.

#proxy_access_log = logs/access.log       # Path for proxy port request access
                                          # logs. Set this value to `off` to
                                          # disable logging proxy requests.
                                          # If this value is a relative path,
                                          # it will be placed under the
                                          # `prefix` location.

#proxy_error_log = logs/error.log         # Path for proxy port request error
                                          # logs. The granularity of these logs
                                          # is adjusted by the `log_level`
                                          # property.

#admin_access_log = logs/admin_access.log # Path for Admin API request access
                                          # logs. Set this value to `off` to
                                          # disable logging Admin API requests.
                                          # If this value is a relative path,
                                          # it will be placed under the
                                          # `prefix` location.

#admin_error_log = logs/error.log         # Path for Admin API request error
                                          # logs. The granularity of these logs
                                          # is adjusted by the `log_level`
                                          # property.

#status_access_log = off                  # Path for Status API request access
                                          # logs. The default value of `off`
                                          # implies that loggin for this API
                                          # is disabled by default.
                                          # If this value is a relative path,
                                          # it will be placed under the
                                          # `prefix` location.

#status_error_log = logs/status_error.log # Path for Status API request error
                                          # logs. The granularity of these logs
                                          # is adjusted by the `log_level`
                                          # property.

#plugins = bundled               # Comma-separated list of plugins this node
                                 # should load. By default, only plugins
                                 # bundled in official distributions are
                                 # loaded via the `bundled` keyword.
                                 #
                                 # Loading a plugin does not enable it by
                                 # default, but only instructs Kong to load its
                                 # source code, and allows to configure the
                                 # plugin via the various related Admin API
                                 # endpoints.
                                 #
                                 # The specified name(s) will be substituted as
                                 # such in the Lua namespace:
                                 # `kong.plugins.{name}.*`.
                                 #
                                 # When the `off` keyword is specified as the
                                 # only value, no plugins will be loaded.
                                 #
                                 # `bundled` and plugin names can be mixed
                                 # together, as the following examples suggest:
                                 #
                                 # - `plugins = bundled,custom-auth,custom-log`
                                 #   will include the bundled plugins plus two
                                 #   custom ones
                                 # - `plugins = custom-auth,custom-log` will
                                 #   *only* include the `custom-auth` and
                                 #   `custom-log` plugins.
                                 # - `plugins = off` will not include any
                                 #   plugins
                                 #
                                 # **Note:** Kong will not start if some
                                 # plugins were previously configured (i.e.
                                 # have rows in the database) and are not
                                 # specified in this list.  Before disabling a
                                 # plugin, ensure all instances of it are
                                 # removed before restarting Kong.
                                 #
                                 # **Note:** Limiting the amount of available
                                 # plugins can improve P99 latency when
                                 # experiencing LRU churning in the database
                                 # cache (i.e. when the configured
                                 # `mem_cache_size`) is full.

#go_pluginserver_exe = /usr/local/bin/go-pluginserver
                                 # Path for the go-pluginserver executable,
                                 # used for running Kong plugins written in Go.

#go_plugins_dir = off            # Directory for installing Kong plugins
                                 # written in Go.
                                 #
                                 # This value can be set to `off`, thus disabling
                                 # the plugin server and Go plugin loading.

#anonymous_reports = on          # Send anonymous usage data such as error
                                 # stack traces to help improve Kong.

#------------------------------------------------------------------------------
# HYBRID MODE
#------------------------------------------------------------------------------

#role = traditional              # Use this setting to enable Hybrid Mode,
                                 # This allows running some Kong nodes in a
                                 # control plane role with a database and
                                 # have them deliver configuration updates
                                 # to other nodes running to DB-less running in
                                 # a Data Plane role.
                                 #
                                 # Valid values to this setting are:
                                 #
                                 # - `traditional`: do not use Hybrid Mode.
                                 # - `control_plane`: this node runs in a
                                 #   control plane role. It can use a database
                                 #   and will deliver configuration updates
                                 #   to data plane nodes.
                                 # - `data_plane`: this is a data plane node.
                                 #   It runs DB-less and receives configuration
                                 #   updates from a control plane node.

#cluster_cert =                  # Filename of the cluster certificate to use
                                 # when establishing secure communication
                                 # between control and data plane nodes.
                                 # You can use the `kong hybrid` command to
                                 # generate the certificate/key pair.

#cluster_cert_key =              # Filename of the cluster certificate key to
                                 # use when establishing secure communication
                                 # between control and data plane nodes.
                                 # You can use the `kong hybrid` command to
                                 # generate the certificate/key pair.

#cluster_control_plane =         # To be used by data plane nodes only:
                                 # address of the control plane node from
                                 # which configuration updates will be fetched,
                                 # in `host:port` format.

#cluster_listen = <IP_ADDRESS>:8005
                         # Comma-separated list of addresses and ports on
                         # which the cluster control plane server should listen
                         # for data plane connections.
                         # The cluster communication port of the control plane
                         # must be accessible by all the data planes
                         # within the same cluster. This port is mTLS protected
                         # to ensure end-to-end security and integrity.
                         #
                         # This setting has no effect if `role` is not set to
                         # `control_plane`.

#------------------------------------------------------------------------------
# NGINX
#------------------------------------------------------------------------------

#proxy_listen = <IP_ADDRESS>:8000 reuseport backlog=16384, <IP_ADDRESS>:8443 http2 ssl reuseport backlog=16384
                         # Comma-separated list of addresses and ports on
                         # which the proxy server should listen for
                         # HTTP/HTTPS traffic.
                         # The proxy server is the public entry point of Kong,
                         # which proxies traffic from your consumers to your
                         # backend services. This value accepts IPv4, IPv6, and
                         # hostnames.
                         #
                         # Some suffixes can be specified for each pair:
                         #
                         # - `ssl` will require that all connections made
                         #   through a particular address/port be made with TLS
                         #   enabled.
                         # - `http2` will allow for clients to open HTTP/2
                         #   connections to Kong's proxy server.
                         # - `proxy_protocol` will enable usage of the
                         #   PROXY protocol for a given address/port.
                         # - `deferred` instructs to use a deferred accept on
                         #   Linux (the TCP_DEFER_ACCEPT socket option).
                         # - `bind` instructs to make a separate bind() call
                         #   for a given address:port pair.
                         # - `reuseport` instructs to create an individual
                         #   listening socket for each worker process
                         #   allowing the Kernel to better distribute incoming
                         #   connections between worker processes
                         # - `backlog=N` sets the maximum length for the queue
                         #   of pending TCP connections. This number should
                         #   not be too small in order to prevent clients
                         #   seeing "Connection refused" error connecting to
                         #   a busy Kong instance.
                         #   **Note:** on Linux, this value is limited by the
                         #   setting of `net.core.somaxconn` Kernel parameter.
                         #   In order for the larger `backlog` set here to take
                         #   effect it is necessary to raise
                         #   `net.core.somaxconn` at the same time to match or
                         #   exceed the `backlog` number set.
                         #
                         # This value can be set to `off`, thus disabling
                         # the HTTP/HTTPS proxy port for this node.
                         # If stream_listen is also set to `off`, this enables
                         # 'control-plane' mode for this node
                         # (in which all traffic proxying capabilities are
                         # disabled). This node can then be used only to
                         # configure a cluster of Kong
                         # nodes connected to the same datastore.
                         #
                         # Example:
                         # `proxy_listen = <IP_ADDRESS>:443 ssl, <IP_ADDRESS>:444 http2 ssl`
                         #
                         # See http://nginx.org/en/docs/http/ngx_http_core_module.html#listen
                         # for a description of the accepted formats for this
                         # and other `*_listen` values.
                         #
                         # See https://www.nginx.com/resources/admin-guide/proxy-protocol/
                         # for more details about the `proxy_protocol`
                         # parameter.
                         #
                         # Not all `*_listen` values accept all formats
                         # specified in nginx's documentation.

#stream_listen = off
                         # Comma-separated list of addresses and ports on
                         # which the stream mode should listen.
                         #
                         # This value accepts IPv4, IPv6, and hostnames.
                         # Some suffixes can be specified for each pair:
                         # - `proxy_protocol` will enable usage of the
                         #   PROXY protocol for a given address/port.
                         # - `bind` instructs to make a separate bind() call
                         #   for a given address:port pair.
                         # - `reuseport` instructs to create an individual
                         #   listening socket for each worker process
                         #   allowing the Kernel to better distribute incoming
                         #   connections between worker processes
                         # - `backlog=N` sets the maximum length for the queue
                         #   of pending TCP connections. This number should
                         #   not be too small in order to prevent clients
                         #   seeing "Connection refused" error connecting to
                         #   a busy Kong instance.
                         #   **Note:** on Linux, this value is limited by the
                         #   setting of `net.core.somaxconn` Kernel parameter.
                         #   In order for the larger `backlog` set here to take
                         #   effect it is necessary to raise
                         #   `net.core.somaxconn` at the same time to match or
                         #   exceed the `backlog` number set.
                         #
                         # **Note:** The `ssl` suffix is not supported,
                         # and each address/port will accept TCP with or
                         # without TLS enabled.
                         #
                         # Examples:
                         #
                         # ```
                         # stream_listen = <IP_ADDRESS>:7000 reuseport backlog=16384
                         # stream_listen = <IP_ADDRESS>:989 reuseport backlog=65536, <IP_ADDRESS>:20
                         # stream_listen = [::1]:1234 backlog=16384
                         # ```
                         #
                         # By default this value is set to `off`, thus
                         # disabling the stream proxy port for this node.

# See http://nginx.org/en/docs/stream/ngx_stream_core_module.html#listen
# for a description of the formats that Kong might accept in stream_listen.

#admin_listen = <IP_ADDRESS>:8001 reuseport backlog=16384, <IP_ADDRESS>:8444 http2 ssl reuseport backlog=16384
                         # Comma-separated list of addresses and ports on
                         # which the Admin interface should listen.
                         # The Admin interface is the API allowing you to
                         # configure and manage Kong.
                         # Access to this interface should be *restricted*
                         # to Kong administrators *only*. This value accepts
                         # IPv4, IPv6, and hostnames.
                         #
                         # Some suffixes can be specified for each pair:
                         #
                         # - `ssl` will require that all connections made
                         #   through a particular address/port be made with TLS
                         #   enabled.
                         # - `http2` will allow for clients to open HTTP/2
                         #   connections to Kong's proxy server.
                         # - `proxy_protocol` will enable usage of the
                         #   PROXY protocol for a given address/port.
                         # - `deferred` instructs to use a deferred accept on
                         #   Linux (the TCP_DEFER_ACCEPT socket option).
                         # - `bind` instructs to make a separate bind() call
                         #   for a given address:port pair.
                         # - `reuseport` instructs to create an individual
                         #   listening socket for each worker process
                         #   allowing the Kernel to better distribute incoming
                         #   connections between worker processes
                         # - `backlog=N` sets the maximum length for the queue
                         #   of pending TCP connections. This number should
                         #   not be too small in order to prevent clients
                         #   seeing "Connection refused" error connecting to
                         #   a busy Kong instance.
                         #   **Note:** on Linux, this value is limited by the
                         #   setting of `net.core.somaxconn` Kernel parameter.
                         #   In order for the larger `backlog` set here to take
                         #   effect it is necessary to raise
                         #   `net.core.somaxconn` at the same time to match or
                         #   exceed the `backlog` number set.
                         #
                         # This value can be set to `off`, thus disabling
                         # the Admin interface for this node, enabling a
                         # 'data-plane' mode (without configuration
                         # capabilities) pulling its configuration changes
                         # from the database.
                         #
                         # Example: `admin_listen = <IP_ADDRESS>:8444 http2 ssl`

 #status_listen = off    # Comma-separated list of addresses and ports on
                         # which the Status API should listen.
                         # The Status API is a read-only endpoint
                         # allowing monitoring tools to retrieve metrics,
                         # healthiness, and other non-sensitive information
                         # of the current Kong node.
                         #
                         # This value can be set to `off`, disabling
                         # the Status API for this node.
                         #
                         # Example: `status_listen = <IP_ADDRESS>:8100`

#nginx_user = nobody nobody      # Defines user and group credentials used by
                                 # worker processes. If group is omitted, a
                                 # group whose name equals that of user is
                                 # used.
                                 #
                                 # Example: `nginx_user = nginx www`

#nginx_worker_processes = auto   # Determines the number of worker processes
                                 # spawned by Nginx.
                                 #
                                 # See http://nginx.org/en/docs/ngx_core_module.html#worker_processes
                                 # for detailed usage of the equivalent Nginx
                                 # directive and a description of accepted
                                 # values.

#nginx_daemon = on               # Determines whether Nginx will run as a daemon
                                 # or as a foreground process. Mainly useful
                                 # for development or when running Kong inside
                                 # a Docker environment.
                                 #
                                 # See http://nginx.org/en/docs/ngx_core_module.html#daemon.

#mem_cache_size = 128m           # Size of each of the two in-memory caches
                                 # for database entities. The accepted units are
                                 # `k` and `m`, with a minimum recommended value of
                                 # a few MBs.
                                 #
                                 # **Note**: As this option controls the size of two
                                 # different cache entries, the total memory Kong
                                 # uses to cache entities might be double this value.

#ssl_cipher_suite = intermediate # Defines the TLS ciphers served by Nginx.
                                 # Accepted values are `modern`,
                                 # `intermediate`, `old`, or `custom`.
                                 #
                                 # See https://wiki.mozilla.org/Security/Server_Side_TLS
                                 # for detailed descriptions of each cipher
                                 # suite.

#ssl_ciphers =                   # Defines a custom list of TLS ciphers to be
                                 # served by Nginx. This list must conform to
                                 # the pattern defined by `openssl ciphers`.
                                 # This value is ignored if `ssl_cipher_suite`
                                 # is not `custom`.

#ssl_cert =                      # The absolute path to the SSL certificate for
                                 # `proxy_listen` values with SSL enabled.

#ssl_cert_key =                  # The absolute path to the SSL key for
                                 # `proxy_listen` values with SSL enabled.

#client_ssl = off                # Determines if Nginx should send client-side
                                 # SSL certificates when proxying requests.

#client_ssl_cert =               # If `client_ssl` is enabled, the absolute
                                 # path to the client SSL certificate for the
                                 # `proxy_ssl_certificate` directive. Note that
                                 # this value is statically defined on the
                                 # node, and currently cannot be configured on
                                 # a per-API basis.

#client_ssl_cert_key =           # If `client_ssl` is enabled, the absolute
                                 # path to the client SSL key for the
                                 # `proxy_ssl_certificate_key` address. Note
                                 # this value is statically defined on the
                                 # node, and currently cannot be configured on
                                 # a per-API basis.

#admin_ssl_cert =                # The absolute path to the SSL certificate for
                                 # `admin_listen` values with SSL enabled.

#admin_ssl_cert_key =            # The absolute path to the SSL key for
                                 # `admin_listen` values with SSL enabled.

#headers = server_tokens, latency_tokens
                                 # Comma-separated list of headers Kong should
                                 # inject in client responses.
                                 #
                                 # Accepted values are:
                                 # - `Server`: Injects `Server: kong/x.y.z`
                                 #   on Kong-produced response (e.g. Admin
                                 #   API, rejected requests from auth plugin).
                                 # - `Via`: Injects `Via: kong/x.y.z` for
                                 #   successfully proxied requests.
                                 # - `X-Kong-Proxy-Latency`: Time taken
                                 #   (in milliseconds) by Kong to process
                                 #   a request and run all plugins before
                                 #   proxying the request upstream.
                                 # - `X-Kong-Response-Latency`: time taken
                                 #   (in millisecond) by Kong to produce
                                 #   a response in case of e.g. plugin
                                 #   short-circuiting the request, or in
                                 #   in case of an error.
                                 # - `X-Kong-Upstream-Latency`: Time taken
                                 #   (in milliseconds) by the upstream
                                 #   service to send response headers.
                                 # - `X-Kong-Admin-Latency`: Time taken
                                 #   (in milliseconds) by Kong to process
                                 #   an Admin API request.
                                 # - `X-Kong-Upstream-Status`: The HTTP status
                                 #   code returned by the upstream service.
                                 #   This is particularly useful for clients to
                                 #   distinguish upstream statuses if the
                                 #   response is rewritten by a plugin.
                                 # - `server_tokens`: Same as specifying both
                                 #   `Server` and `Via`.
                                 # - `latency_tokens`: Same as specifying
                                 #   `X-Kong-Proxy-Latency`,
                                 #   `X-Kong-Response-Latency`,
                                 #   `X-Kong-Admin-Latency` and
                                 #   `X-Kong-Upstream-Latency`
                                 #
                                 # In addition to those, this value can be set
                                 # to `off`, which prevents Kong from injecting
                                 # any of the above headers. Note that this
                                 # does not prevent plugins from injecting
                                 # headers of their own.
                                 #
                                 # Example: `headers = via, latency_tokens`

#trusted_ips =                   # Defines trusted IP addresses blocks that are
                                 # known to send correct `X-Forwarded-*`
                                 # headers.
                                 # Requests from trusted IPs make Kong forward
                                 # their `X-Forwarded-*` headers upstream.
                                 # Non-trusted requests make Kong insert its
                                 # own `X-Forwarded-*` headers.
                                 #
                                 # This property also sets the
                                 # `set_real_ip_from` directive(s) in the Nginx
                                 # configuration. It accepts the same type of
                                 # values (CIDR blocks) but as a
                                 # comma-separated list.
                                 #
                                 # To trust *all* /!\ IPs, set this value to
                                 # `<IP_ADDRESS>/0,::/0`.
                                 #
                                 # If the special value `unix:` is specified,
                                 # all UNIX-domain sockets will be trusted.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_realip_module.html#set_real_ip_from
                                 # for examples of accepted values.

#real_ip_header = X-Real-IP      # Defines the request header field whose value
                                 # will be used to replace the client address.
                                 # This value sets the `ngx_http_realip_module`
                                 # directive of the same name in the Nginx
                                 # configuration.
                                 #
                                 # If this value receives `proxy_protocol`:
                                 #
                                 # - at least one of the `proxy_listen` entries
                                 #   must have the `proxy_protocol` flag
                                 #   enabled.
                                 # - the `proxy_protocol` parameter will be
                                 #   appended to the `listen` directive of the
                                 #   Nginx template.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_header
                                 # for a description of this directive.

#real_ip_recursive = off         # This value sets the `ngx_http_realip_module`
                                 # directive of the same name in the Nginx
                                 # configuration.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_recursive
                                 # for a description of this directive.

#client_max_body_size = 0        # Defines the maximum request body size allowed
                                 # by requests proxied by Kong, specified in
                                 # the Content-Length request header. If a
                                 # request exceeds this limit, Kong will
                                 # respond with a 413 (Request Entity Too
                                 # Large). Setting this value to 0 disables
                                 # checking the request body size.

# See http://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size
# for further description of this parameter. Numeric values may be suffixed
# with `k` or `m` to denote limits in terms of kilobytes or megabytes.

#client_body_buffer_size = 8k    # Defines the buffer size for reading the
                                 # request body. If the client request body is
                                 # larger than this value, the body will be
                                 # buffered to disk. Note that when the body is
                                 # buffered to disk Kong plugins that access or
                                 # manipulate the request body may not work, so
                                 # it is advisable to set this value as high as
                                 # possible (e.g., set it as high as
                                 # `client_max_body_size` to force request
                                 # bodies to be kept in memory). Do note that
                                 # high-concurrency environments will require
                                 # significant memory allocations to process
                                 # many concurrent large request bodies.

# See http://nginx.org/en/docs/http/ngx_http_core_module.html#client_body_buffer_size
# for further description of this parameter. Numeric values may be suffixed
# with `k` or `m` to denote limits in terms of kilobytes or megabytes.

#error_default_type = text/plain  # Default MIME type to use when the request
                                  # `Accept` header is missing and Nginx
                                  # is returning an error for the request.
                                  # Accepted values are `text/plain`,
                                  # `text/html`, `application/json`, and
                                  # `application/xml`.

#------------------------------------------------------------------------------
# NGINX injected directives
#------------------------------------------------------------------------------

# Nginx directives can be dynamically injected in the runtime nginx.conf file
# without requiring a custom Nginx configuration template.
#
# All configuration properties respecting the naming scheme
# `nginx_<namespace>_<directive>` will result in `<directive>` being injected in
# the Nginx configuration block corresponding to the property's `<namespace>`.
# Example:
#   `nginx_proxy_large_client_header_buffers = 8 24k`
#
#   Will inject the following directive in Kong's proxy `server {}` block:
#
#   `large_client_header_buffers 8 24k;`
#
# The following namespaces are supported:
#
# - `nginx_main_<directive>`: Injects `<directive>` in Kong's configuration
#   `main` context.
# - `nginx_events_<directive>`: Injects `<directive>` in Kong's `events {}`
#    block.
# - `nginx_http_<directive>`: Injects `<directive>` in Kong's `http {}` block.
# - `nginx_proxy_<directive>`: Injects `<directive>` in Kong's proxy
#   `server {}` block.
# - `nginx_upstream_<directive>`: Injects `<directive>` in Kong's proxy
#   `upstream {}` block.
# - `nginx_admin_<directive>`: Injects `<directive>` in Kong's Admin API
#   `server {}` block.
# - `nginx_status_<directive>`: Injects `<directive>` in Kong's Status API
#   `server {}` block  (only effective if `status_listen` is enabled).
# - `nginx_stream_<directive>`: Injects `<directive>` in Kong's stream module
#   `stream {}` block (only effective if `stream_listen` is enabled).
# - `nginx_sproxy_<directive>`: Injects `<directive>` in Kong's stream module
#   `server {}` block (only effective if `stream_listen` is enabled).
# - `nginx_supstream_<directive>`: Injects `<directive>` in Kong's stream
#   module `upstream {}` block.
#
# As with other configuration properties, Nginx directives can be injected via
# environment variables when capitalized and prefixed with `KONG_`.
# Example:
#   `KONG_NGINX_HTTP_SSL_PROTOCOLS` -> `nginx_http_ssl_protocols`
#
#   Will inject the following directive in Kong's `http {}` block:
#
#   `ssl_protocols <value>;`
#
#   If different sets of protocols are desired between the proxy and Admin API
#   server, you may specify `nginx_proxy_ssl_protocols` and/or
#   `nginx_admin_ssl_protocols`, both of which taking precedence over the
#   `http {}` block.

#nginx_http_ssl_protocols = TLSv1.1 TLSv1.2 TLSv1.3
                                 # Enables the specified protocols for
                                 # client-side connections. The set of
                                 # supported protocol versions also depends
                                 # on the version of OpenSSL Kong was built
                                 # with.
                                 #
                                 # This value is ignored if `ssl_cipher_suite`
                                 # is not `custom`.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_protocols

#nginx_http_ssl_prefer_server_ciphers = on
                                 # Specifies that server ciphers should be
                                 # preferred over client ciphers when using
                                 # the SSLv3 and TLS protocols
                                 #
                                 # This value is ignored if `ssl_cipher_suite`
                                 # is not `custom`.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_prefer_server_ciphers

#nginx_http_ssl_session_tickets = on
                                 # Enables or disables session resumption through
                                 # TLS session tickets. This is has no impact when
                                 # used with TLSv1.3.
                                 #
                                 # Kong enables this by default for performance
                                 # reasons, but it has security implications:
                                 # https://github.com/mozilla/server-side-tls/issues/135
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_tickets

#nginx_http_ssl_session_timeout = 1d
                                 # Specifies a time during which a client may
                                 # reuse the session parameters. See the rationale:
                                 # https://github.com/mozilla/server-side-tls/issues/198
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_timeout

#nginx_upstream_keepalive = 60   # Sets the maximum number of idle keepalive
                                 # connections to upstream servers that are
                                 # preserved in the cache of each worker
                                 # process. When this number is exceeded, the
                                 # least recently used connections are closed.
                                 # A value of `NONE` will disable this behavior
                                 # altogether, forcing each upstream request
                                 # to open a new connection.
                                 # See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive

#nginx_upstream_keepalive_requests = 100
                                 # Sets the maximum number of requests that can
                                 # be served through one keepalive connection.
                                 # After the maximum number of requests is
                                 # made, the connection is closed.
                                 # See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive_requests

#nginx_upstream_keepalive_timeout = 60s
                                 # Sets a timeout during which an idle
                                 # keepalive connection to an upstream server
                                 # will stay open.
                                 # See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive_timeout

#------------------------------------------------------------------------------
# DATASTORE
#------------------------------------------------------------------------------

# Kong can run with a database to store coordinated data between Kong nodes in
# a cluster, or without a database, where each node stores its information
# independently in memory.
#
# When using a database, Kong will store data for all its entities (such as
# Routes, Services, Consumers, and Plugins) in either Cassandra or PostgreSQL,
# and all Kong nodes belonging to the same cluster must connect themselves
# to the same database.
#
# Kong supports the following database versions:
# - **PostgreSQL**: 9.5 and above.
# - **Cassandra**: 2.2 and above.
#
# When not using a database, Kong is said to be in "DB-less mode": it will keep
# its entities in memory, and each node needs to have this data entered via a
# declarative configuration file, which can be specified through the
# `declarative_config` property, or via the Admin API using the `/config`
# endpoint.

#database = postgres             # Determines which of PostgreSQL or Cassandra
                                 # this node will use as its datastore.
                                 # Accepted values are `postgres`,
                                 # `cassandra`, and `off`.

#pg_host = <IP_ADDRESS>             # Host of the Postgres server.
#pg_port = 5432                  # Port of the Postgres server.
#pg_timeout = 5000               # Defines the timeout (in ms), for connecting,
                                 # reading and writing.

#pg_user = kong                  # Postgres user.
#pg_password =                   # Postgres user's password.
#pg_database = kong              # The database name to connect to.

#pg_schema =                     # The database schema to use. If unspecified,
                                 # Kong will respect the `search_path` value of
                                 # your PostgreSQL instance.

#pg_ssl = off                    # Toggles client-server TLS connections
                                 # between Kong and PostgreSQL.

#pg_ssl_verify = off             # Toggles server certificate verification if
                                 # `pg_ssl` is enabled.
                                 # See the `lua_ssl_trusted_certificate`
                                 # setting to specify a certificate authority.

#pg_max_concurrent_queries = 0   # Sets the maximum number of concurrent queries
                                 # that can be executing at any given time. This
                                 # limit is enforced per worker process; the
                                 # total number of concurrent queries for this
                                 # node will be will be:
                                 # `pg_max_concurrent_queries * nginx_worker_processes`.
                                 #
                                 # The default value of 0 removes this
                                 # concurrency limitation.

#pg_semaphore_timeout = 60000    # Defines the timeout (in ms) after which
                                 # PostgreSQL query semaphore resource
                                 # acquisition attempts will fail. Such
                                 # failures will generally result in the
                                 # associated proxy or Admin API request
                                 # failing with an HTTP 500 status code.
                                 # Detailed discussion of this behavior is
                                 # available in the online documentation.

#cassandra_contact_points = <IP_ADDRESS>  # A comma-separated list of contact
                                       # points to your cluster.
                                       # You may specify IP addresses or
                                       # hostnames. Note that the port
                                       # component of SRV records will be
                                       # ignored in favor of `cassandra_port`.
                                       # When connecting to a multi-DC cluster,
                                       # ensure that contact points from the
                                       # local datacenter are specified first
                                       # in this list.

#cassandra_port = 9042           # The port on which your nodes are listening
                                 # on. All your nodes and contact points must
                                 # listen on the same port. Will be created if
                                 # it doesn't exist.

#cassandra_keyspace = kong       # The keyspace to use in your cluster.

#cassandra_consistency = ONE     # Consistency setting to use when reading/
                                 # writing to the Cassandra cluster.
                                 #
#cassandra_timeout = 5000        # Defines the timeout (in ms) for reading
                                 # and writing.

#cassandra_ssl = off             # Toggles client-to-node TLS connections
                                 # between Kong and Cassandra.

#cassandra_ssl_verify = off      # Toggles server certificate verification if
                                 # `cassandra_ssl` is enabled.
                                 # See the `lua_ssl_trusted_certificate`
                                 # setting to specify a certificate authority.

#cassandra_username = kong       # Username when using the
                                 # `PasswordAuthenticator` scheme.

#cassandra_password =            # Password when using the
                                 # `PasswordAuthenticator` scheme.

#cassandra_lb_policy = RequestRoundRobin  # Load balancing policy to use when
                                          # distributing queries across your
                                          # Cassandra cluster.
                                          # Accepted values are:
                                          # `RoundRobin`, `RequestRoundRobin`,
                                          # `DCAwareRoundRobin`, and
                                          # `RequestDCAwareRoundRobin`.
                                          # Policies prefixed with "Request"
                                          # make efficient use of established
                                          # connections throughout the same
                                          # request.
                                          # Prefer "DCAware" policies if and
                                          # only if you are using a
                                          # multi-datacenter cluster.

#cassandra_local_datacenter =    # When using the `DCAwareRoundRobin`
                                 # or `RequestDCAwareRoundRobin` load
                                 # balancing policy, you must specify the name
                                 # of the local (closest) datacenter for this
                                 # Kong node.

#cassandra_refresh_frequency = 60          # Frequency (in seconds) at which
                                           # the cluster topology will be
                                           # checked for new or decommissioned
                                           # nodes.
                                           # A value of `0` will disable this
                                           # check, and the cluster topology
                                           # will never be refreshed.

#cassandra_repl_strategy = SimpleStrategy  # When migrating for the first time,
                                           # Kong will use this setting to
                                           # create your keyspace.
                                           # Accepted values are
                                           # `SimpleStrategy` and
                                           # `NetworkTopologyStrategy`.

#cassandra_repl_factor = 1       # When migrating for the first time, Kong
                                 # will create the keyspace with this
                                 # replication factor when using the
                                 # `SimpleStrategy`.

#cassandra_data_centers = dc1:2,dc2:3  # When migrating for the first time,
                                       # will use this setting when using the
                                       # `NetworkTopologyStrategy`.
                                       # The format is a comma-separated list
                                       # made of `<dc_name>:<repl_factor>`.

#cassandra_schema_consensus_timeout = 10000  # Defines the timeout (in ms) for
                                             # the waiting period to reach a
                                             # schema consensus between your
                                             # Cassandra nodes.
                                             # This value is only used during
                                             # migrations.

#declarative_config =           # The path to the declarative configuration
                                # file which holds the specification of all
                                # entities (Routes, Services, Consumers, etc.)
                                # to be used when the `database` is set to
                                # `off`.
                                #
                                # Entities are stored in Kong's in-memory cache,
                                # so you must ensure that enough memory is
                                # allocated to it via the `mem_cache_size`
                                # property. You must also ensure that items
                                # in the cache never expire, which means that
                                # `db_cache_ttl` should preserve its default
                                # value of 0.

#------------------------------------------------------------------------------
# DATASTORE CACHE
#------------------------------------------------------------------------------

# In order to avoid unnecessary communication with the datastore, Kong caches
# entities (such as APIs, Consumers, Credentials...) for a configurable period
# of time. It also handles invalidations if such an entity is updated.
#
# This section allows for configuring the behavior of Kong regarding the
# caching of such configuration entities.

#db_update_frequency = 5         # Frequency (in seconds) at which to check for
                                 # updated entities with the datastore.
                                 #
                                 # When a node creates, updates, or deletes an
                                 # entity via the Admin API, other nodes need
                                 # to wait for the next poll (configured by
                                 # this value) to eventually purge the old
                                 # cached entity and start using the new one.

#db_update_propagation = 0       # Time (in seconds) taken for an entity in the
                                 # datastore to be propagated to replica nodes
                                 # of another datacenter.
                                 #
                                 # When in a distributed environment such as
                                 # a multi-datacenter Cassandra cluster, this
                                 # value should be the maximum number of
                                 # seconds taken by Cassandra to propagate a
                                 # row to other datacenters.
                                 #
                                 # When set, this property will increase the
                                 # time taken by Kong to propagate the change
                                 # of an entity.
                                 #
                                 # Single-datacenter setups or PostgreSQL
                                 # servers should suffer no such delays, and
                                 # this value can be safely set to 0.

#db_cache_ttl = 0                # Time-to-live (in seconds) of an entity from
                                 # the datastore when cached by this node.
                                 #
                                 # Database misses (no entity) are also cached
                                 # according to this setting.
                                 #
                                 # If set to 0 (default), such cached entities
                                 # or misses never expire.

#db_resurrect_ttl = 30           # Time (in seconds) for which stale entities
                                 # from the datastore should be resurrected for
                                 # when they cannot be refreshed (e.g., the
                                 # datastore is unreachable). When this TTL
                                 # expires, a new attempt to refresh the stale
                                 # entities will be made.

#db_cache_warmup_entities = services, plugins
                                 # Entities to be pre-loaded from the datastore
                                 # into the in-memory cache at Kong start-up.
                                 # This speeds up the first access of endpoints
                                 # that use the given entities.
                                 #
                                 # When the `services` entity is configured
                                 # for warmup, the DNS entries for values in
                                 # its `host` attribute are pre-resolved
                                 # asynchronously as well.
                                 #
                                 # Cache size set in `mem_cache_size` should
                                 # be set to a value large enough to hold all
                                 # instances of the specified entities.
                                 # If the size is insufficient, Kong will log
                                 # a warning.

#------------------------------------------------------------------------------
# DNS RESOLVER
#------------------------------------------------------------------------------

# By default the DNS resolver will use the standard configuration files
# `/etc/hosts` and `/etc/resolv.conf`. The settings in the latter file will be
# overridden by the environment variables `LOCALDOMAIN` and `RES_OPTIONS` if
# they have been set.
#
# Kong will resolve hostnames as either `SRV` or `A` records (in that order, and
# `CNAME` records will be dereferenced in the process).
# In case a name was resolved as an `SRV` record it will also override any given
# port number by the `port` field contents received from the DNS server.
#
# The DNS options `SEARCH` and `NDOTS` (from the `/etc/resolv.conf` file) will
# be used to expand short names to fully qualified ones. So it will first try
# the entire `SEARCH` list for the `SRV` type, if that fails it will try the
# `SEARCH` list for `A`, etc.
#
# For the duration of the `ttl`, the internal DNS resolver will loadbalance each
# request it gets over the entries in the DNS record. For `SRV` records the
# `weight` fields will be honored, but it will only use the lowest `priority`
# field entries in the record.

#dns_resolver =                  # Comma separated list of nameservers, each
                                 # entry in `ip[:port]` format to be used by
                                 # Kong. If not specified the nameservers in
                                 # the local `resolv.conf` file will be used.
                                 # Port defaults to 53 if omitted. Accepts
                                 # both IPv4 and IPv6 addresses.

#dns_hostsfile = /etc/hosts      # The hosts file to use. This file is read
                                 # once and its content is static in memory.
                                 # To read the file again after modifying it,
                                 # Kong must be reloaded.

#dns_order = LAST,SRV,A,CNAME    # The order in which to resolve different
                                 # record types. The `LAST` type means the
                                 # type of the last successful lookup (for the
                                 # specified name). The format is a (case
                                 # insensitive) comma separated list.

#dns_valid_ttl =                 # By default, DNS records are cached using
                                 # the TTL value of a response. If this
                                 # property receives a value (in seconds), it
                                 # will override the TTL for all records.

#dns_stale_ttl = 4               # Defines, in seconds, how long a record will
                                 # remain in cache past its TTL. This value
                                 # will be used while the new DNS record is
                                 # fetched in the background.
                                 # Stale data will be used from expiry of a
                                 # record until either the refresh query
                                 # completes, or the `dns_stale_ttl` number of
                                 # seconds have passed.

#dns_not_found_ttl = 30          # TTL in seconds for empty DNS responses and
                                 # "(3) name error" responses.

#dns_error_ttl = 1               # TTL in seconds for error responses.

#dns_no_sync = off               # If enabled, then upon a cache-miss every
                                 # request will trigger its own dns query.
                                 # When disabled multiple requests for the
                                 # same name/type will be synchronised to a
                                 # single query.

#------------------------------------------------------------------------------
# TUNING & BEHAVIOR
#------------------------------------------------------------------------------

#router_consistency = strict     # Defines whether this node should rebuild its
                                 # router synchronously or asynchronously (the
                                 # router is rebuilt every time a Route or a
                                 # Service is updated via the Admin API or
                                 # loading a declarative configuration file).
                                 #
                                 # Accepted values are:
                                 #
                                 # - `strict`: the router will be rebuilt
                                 #   synchronously, causing incoming requests to
                                 #   be delayed until the rebuild is finished.
                                 # - `eventual`: the router will be rebuilt
                                 #   asynchronously via a recurring background
                                 #   job running every second inside of each
                                 #   worker.
                                 #
                                 # Note that `strict` ensures that all workers
                                 # of a given node will always proxy requests
                                 # with an identical router, but that increased
                                 # long tail latency can be observed if
                                 # frequent Routes and Services updates are
                                 # expected.
                                 # Using `eventual` will help preventing long
                                 # tail latency issues in such cases, but may
                                 # cause workers to route requests differently
                                 # for a short period of time after Routes and
                                 # Services updates.

#router_update_frequency = 1     # Defines how often the router changes are
                                 # checked with a background job. When a change
                                 # is detected, a new router will be built. By
                                 # default we check for changes every second.
                                 # Raising this value will decrease the load on
                                 # database servers and result in less jitter
                                 # in proxy latency, with downside of longer
                                 # converge time for router updates.

#------------------------------------------------------------------------------
# DEVELOPMENT & MISCELLANEOUS
#------------------------------------------------------------------------------

# Additional settings inherited from lua-nginx-module allowing for more
# flexibility and advanced usage.
#
# See the lua-nginx-module documentation for more information:
# https://github.com/openresty/lua-nginx-module

#lua_ssl_trusted_certificate =   # Absolute path to the certificate
                                 # authority file for Lua cosockets in PEM
                                 # format. This certificate will be the one
                                 # used for verifying Kong's database
                                 # connections, when `pg_ssl_verify` or
                                 # `cassandra_ssl_verify` are enabled.
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_ssl_trusted_certificate

#lua_ssl_verify_depth = 1        # Sets the verification depth in the server
                                 # certificates chain used by Lua cosockets,
                                 # set by `lua_ssl_trusted_certificate`.
                                 # This includes the certificates configured
                                 # for Kong's database connections.
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_ssl_verify_depth

#lua_package_path = ./?.lua;./?/init.lua;  # Sets the Lua module search path
                                           # (LUA_PATH). Useful when developing
                                           # or using custom plugins not stored
                                           # in the default search path.
                                           #
                                           # See https://github.com/openresty/lua-nginx-module#lua_package_path

#lua_package_cpath =             # Sets the Lua C module search path
                                 # (LUA_CPATH).
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_package_cpath

#lua_socket_pool_size = 30       # Specifies the size limit for every cosocket
                                 # connection pool associated with every remote
                                 # server.
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_socket_pool_size
dev4vin@g33kPC:/etc/kong$ sudo nano kong.conf.default
[sudo] password for dev4vin:
dev4vin@g33kPC:/etc/kong$ cat kong.conf.default
# -----------------------
# Kong configuration file
# -----------------------
#
# The commented-out settings shown in this file represent the default values.
#
# This file is read when `kong start` or `kong prepare` are used. Kong
# generates the Nginx configuration with the settings specified in this file.
#
# All environment variables prefixed with `KONG_` and capitalized will override
# the settings specified in this file.
# Example:
#   `log_level` setting -> `KONG_LOG_LEVEL` env variable
#
# Boolean values can be specified as `on`/`off` or `true`/`false`.
# Lists must be specified as comma-separated strings.
#
# All comments in this file can be removed safely, including the
# commented-out properties.
# You can verify the integrity of your settings with `kong check <conf>`.

#------------------------------------------------------------------------------
# GENERAL
#------------------------------------------------------------------------------

prefix = /usr/local/kong/       # Working directory. Equivalent to Nginx's
                                 # prefix path, containing temporary files
                                 # and logs.
                                 # Each Kong process must have a separate
                                 # working directory.

log_level = notice              # Log level of the Nginx server. Logs are
                                 # found at `<prefix>/logs/error.log`.

# See http://nginx.org/en/docs/ngx_core_module.html#error_log for a list
# of accepted values.

proxy_access_log = logs/access.log       # Path for proxy port request access
                                          # logs. Set this value to `off` to
                                          # disable logging proxy requests.
                                          # If this value is a relative path,
                                          # it will be placed under the
                                          # `prefix` location.

proxy_error_log = logs/error.log         # Path for proxy port request error
                                          # logs. The granularity of these logs
                                          # is adjusted by the `log_level`
                                          # property.

admin_access_log = logs/admin_access.log # Path for Admin API request access
                                          # logs. Set this value to `off` to
                                          # disable logging Admin API requests.
                                          # If this value is a relative path,
                                          # it will be placed under the
                                          # `prefix` location.

admin_error_log = logs/error.log         # Path for Admin API request error
                                          # logs. The granularity of these logs
                                          # is adjusted by the `log_level`
                                          # property.

status_access_log = off                  # Path for Status API request access
                                          # logs. The default value of `off`
                                          # implies that loggin for this API
                                          # is disabled by default.
                                          # If this value is a relative path,
                                          # it will be placed under the
                                          # `prefix` location.

status_error_log = logs/status_error.log # Path for Status API request error
                                          # logs. The granularity of these logs
                                          # is adjusted by the `log_level`
                                          # property.

plugins = bundled               # Comma-separated list of plugins this node
                                 # should load. By default, only plugins
                                 # bundled in official distributions are
                                 # loaded via the `bundled` keyword.
                                 #
                                 # Loading a plugin does not enable it by
                                 # default, but only instructs Kong to load its
                                 # source code, and allows to configure the
                                 # plugin via the various related Admin API
                                 # endpoints.
                                 #
                                 # The specified name(s) will be substituted as
                                 # such in the Lua namespace:
                                 # `kong.plugins.{name}.*`.
                                 #
                                 # When the `off` keyword is specified as the
                                 # only value, no plugins will be loaded.
                                 #
                                 # `bundled` and plugin names can be mixed
                                 # together, as the following examples suggest:
                                 #
                                 # - `plugins = bundled,custom-auth,custom-log`
                                 #   will include the bundled plugins plus two
                                 #   custom ones
                                 # - `plugins = custom-auth,custom-log` will
                                 #   *only* include the `custom-auth` and
                                 #   `custom-log` plugins.
                                 # - `plugins = off` will not include any
                                 #   plugins
                                 #
                                 # **Note:** Kong will not start if some
                                 # plugins were previously configured (i.e.
                                 # have rows in the database) and are not
                                 # specified in this list.  Before disabling a
                                 # plugin, ensure all instances of it are
                                 # removed before restarting Kong.
                                 #
                                 # **Note:** Limiting the amount of available
                                 # plugins can improve P99 latency when
                                 # experiencing LRU churning in the database
                                 # cache (i.e. when the configured
                                 # `mem_cache_size`) is full.

go_pluginserver_exe = /usr/local/bin/go-pluginserver
                                 # Path for the go-pluginserver executable,
                                 # used for running Kong plugins written in Go.

#go_plugins_dir = off            # Directory for installing Kong plugins
                                 # written in Go.
                                 #
                                 # This value can be set to `off`, thus disabling
                                 # the plugin server and Go plugin loading.

#anonymous_reports = on          # Send anonymous usage data such as error
                                 # stack traces to help improve Kong.

#------------------------------------------------------------------------------
# HYBRID MODE
#------------------------------------------------------------------------------

#role = traditional              # Use this setting to enable Hybrid Mode,
                                 # This allows running some Kong nodes in a
                                 # control plane role with a database and
                                 # have them deliver configuration updates
                                 # to other nodes running to DB-less running in
                                 # a Data Plane role.
                                 #
                                 # Valid values to this setting are:
                                 #
                                 # - `traditional`: do not use Hybrid Mode.
                                 # - `control_plane`: this node runs in a
                                 #   control plane role. It can use a database
                                 #   and will deliver configuration updates
                                 #   to data plane nodes.
                                 # - `data_plane`: this is a data plane node.
                                 #   It runs DB-less and receives configuration
                                 #   updates from a control plane node.

#cluster_cert =                  # Filename of the cluster certificate to use
                                 # when establishing secure communication
                                 # between control and data plane nodes.
                                 # You can use the `kong hybrid` command to
                                 # generate the certificate/key pair.

#cluster_cert_key =              # Filename of the cluster certificate key to
                                 # use when establishing secure communication
                                 # between control and data plane nodes.
                                 # You can use the `kong hybrid` command to
                                 # generate the certificate/key pair.

#cluster_control_plane =         # To be used by data plane nodes only:
                                 # address of the control plane node from
                                 # which configuration updates will be fetched,
                                 # in `host:port` format.

#cluster_listen = <IP_ADDRESS>:8005
                         # Comma-separated list of addresses and ports on
                         # which the cluster control plane server should listen
                         # for data plane connections.
                         # The cluster communication port of the control plane
                         # must be accessible by all the data planes
                         # within the same cluster. This port is mTLS protected
                         # to ensure end-to-end security and integrity.
                         #
                         # This setting has no effect if `role` is not set to
                         # `control_plane`.

#------------------------------------------------------------------------------
# NGINX
#------------------------------------------------------------------------------

proxy_listen = <IP_ADDRESS>:8000 reuseport backlog=16384, <IP_ADDRESS>:8443 http2 ssl reuseport backlog=16384
                         # Comma-separated list of addresses and ports on
                         # which the proxy server should listen for
                         # HTTP/HTTPS traffic.
                         # The proxy server is the public entry point of Kong,
                         # which proxies traffic from your consumers to your
                         # backend services. This value accepts IPv4, IPv6, and
                         # hostnames.
                         #
                         # Some suffixes can be specified for each pair:
                         #
                         # - `ssl` will require that all connections made
                         #   through a particular address/port be made with TLS
                         #   enabled.
                         # - `http2` will allow for clients to open HTTP/2
                         #   connections to Kong's proxy server.
                         # - `proxy_protocol` will enable usage of the
                         #   PROXY protocol for a given address/port.
                         # - `deferred` instructs to use a deferred accept on
                         #   Linux (the TCP_DEFER_ACCEPT socket option).
                         # - `bind` instructs to make a separate bind() call
                         #   for a given address:port pair.
                         # - `reuseport` instructs to create an individual
                         #   listening socket for each worker process
                         #   allowing the Kernel to better distribute incoming
                         #   connections between worker processes
                         # - `backlog=N` sets the maximum length for the queue
                         #   of pending TCP connections. This number should
                         #   not be too small in order to prevent clients
                         #   seeing "Connection refused" error connecting to
                         #   a busy Kong instance.
                         #   **Note:** on Linux, this value is limited by the
                         #   setting of `net.core.somaxconn` Kernel parameter.
                         #   In order for the larger `backlog` set here to take
                         #   effect it is necessary to raise
                         #   `net.core.somaxconn` at the same time to match or
                         #   exceed the `backlog` number set.
                         #
                         # This value can be set to `off`, thus disabling
                         # the HTTP/HTTPS proxy port for this node.
                         # If stream_listen is also set to `off`, this enables
                         # 'control-plane' mode for this node
                         # (in which all traffic proxying capabilities are
                         # disabled). This node can then be used only to
                         # configure a cluster of Kong
                         # nodes connected to the same datastore.
                         #
                         # Example:
                         # `proxy_listen = <IP_ADDRESS>:443 ssl, <IP_ADDRESS>:444 http2 ssl`
                         #
                         # See http://nginx.org/en/docs/http/ngx_http_core_module.html#listen
                         # for a description of the accepted formats for this
                         # and other `*_listen` values.
                         #
                         # See https://www.nginx.com/resources/admin-guide/proxy-protocol/
                         # for more details about the `proxy_protocol`
                         # parameter.
                         #
                         # Not all `*_listen` values accept all formats
                         # specified in nginx's documentation.

#stream_listen = off
                         # Comma-separated list of addresses and ports on
                         # which the stream mode should listen.
                         #
                         # This value accepts IPv4, IPv6, and hostnames.
                         # Some suffixes can be specified for each pair:
                         # - `proxy_protocol` will enable usage of the
                         #   PROXY protocol for a given address/port.
                         # - `bind` instructs to make a separate bind() call
                         #   for a given address:port pair.
                         # - `reuseport` instructs to create an individual
                         #   listening socket for each worker process
                         #   allowing the Kernel to better distribute incoming
                         #   connections between worker processes
                         # - `backlog=N` sets the maximum length for the queue
                         #   of pending TCP connections. This number should
                         #   not be too small in order to prevent clients
                         #   seeing "Connection refused" error connecting to
                         #   a busy Kong instance.
                         #   **Note:** on Linux, this value is limited by the
                         #   setting of `net.core.somaxconn` Kernel parameter.
                         #   In order for the larger `backlog` set here to take
                         #   effect it is necessary to raise
                         #   `net.core.somaxconn` at the same time to match or
                         #   exceed the `backlog` number set.
                         #
                         # **Note:** The `ssl` suffix is not supported,
                         # and each address/port will accept TCP with or
                         # without TLS enabled.
                         #
                         # Examples:
                         #
                         # ```
                         # stream_listen = <IP_ADDRESS>:7000 reuseport backlog=16384
                         # stream_listen = <IP_ADDRESS>:989 reuseport backlog=65536, <IP_ADDRESS>:20
                         # stream_listen = [::1]:1234 backlog=16384
                         # ```
                         #
                         # By default this value is set to `off`, thus
                         # disabling the stream proxy port for this node.

# See http://nginx.org/en/docs/stream/ngx_stream_core_module.html#listen
# for a description of the formats that Kong might accept in stream_listen.

admin_listen = <IP_ADDRESS>:8001 reuseport backlog=16384, <IP_ADDRESS>:8444 http2 ssl reuseport backlog=16384
                         # Comma-separated list of addresses and ports on
                         # which the Admin interface should listen.
                         # The Admin interface is the API allowing you to
                         # configure and manage Kong.
                         # Access to this interface should be *restricted*
                         # to Kong administrators *only*. This value accepts
                         # IPv4, IPv6, and hostnames.
                         #
                         # Some suffixes can be specified for each pair:
                         #
                         # - `ssl` will require that all connections made
                         #   through a particular address/port be made with TLS
                         #   enabled.
                         # - `http2` will allow for clients to open HTTP/2
                         #   connections to Kong's proxy server.
                         # - `proxy_protocol` will enable usage of the
                         #   PROXY protocol for a given address/port.
                         # - `deferred` instructs to use a deferred accept on
                         #   Linux (the TCP_DEFER_ACCEPT socket option).
                         # - `bind` instructs to make a separate bind() call
                         #   for a given address:port pair.
                         # - `reuseport` instructs to create an individual
                         #   listening socket for each worker process
                         #   allowing the Kernel to better distribute incoming
                         #   connections between worker processes
                         # - `backlog=N` sets the maximum length for the queue
                         #   of pending TCP connections. This number should
                         #   not be too small in order to prevent clients
                         #   seeing "Connection refused" error connecting to
                         #   a busy Kong instance.
                         #   **Note:** on Linux, this value is limited by the
                         #   setting of `net.core.somaxconn` Kernel parameter.
                         #   In order for the larger `backlog` set here to take
                         #   effect it is necessary to raise
                         #   `net.core.somaxconn` at the same time to match or
                         #   exceed the `backlog` number set.
                         #
                         # This value can be set to `off`, thus disabling
                         # the Admin interface for this node, enabling a
                         # 'data-plane' mode (without configuration
                         # capabilities) pulling its configuration changes
                         # from the database.
                         #
                         # Example: `admin_listen = <IP_ADDRESS>:8444 http2 ssl`

 #status_listen = off    # Comma-separated list of addresses and ports on
                         # which the Status API should listen.
                         # The Status API is a read-only endpoint
                         # allowing monitoring tools to retrieve metrics,
                         # healthiness, and other non-sensitive information
                         # of the current Kong node.
                         #
                         # This value can be set to `off`, disabling
                         # the Status API for this node.
                         #
                         # Example: `status_listen = <IP_ADDRESS>:8100`

nginx_user = nginx www      # Defines user and group credentials used by
                                 # worker processes. If group is omitted, a
                                 # group whose name equals that of user is
                                 # used.
                                 #
                                 # Example: `nginx_user = nginx www`

nginx_worker_processes = auto   # Determines the number of worker processes
                                 # spawned by Nginx.
                                 #
                                 # See http://nginx.org/en/docs/ngx_core_module.html#worker_processes
                                 # for detailed usage of the equivalent Nginx
                                 # directive and a description of accepted
                                 # values.

#nginx_daemon = on               # Determines whether Nginx will run as a daemon
                                 # or as a foreground process. Mainly useful
                                 # for development or when running Kong inside
                                 # a Docker environment.
                                 #
                                 # See http://nginx.org/en/docs/ngx_core_module.html#daemon.

mem_cache_size = 128m           # Size of each of the two in-memory caches
                                 # for database entities. The accepted units are
                                 # `k` and `m`, with a minimum recommended value of
                                 # a few MBs.
                                 #
                                 # **Note**: As this option controls the size of two
                                 # different cache entries, the total memory Kong
                                 # uses to cache entities might be double this value.

#ssl_cipher_suite = intermediate # Defines the TLS ciphers served by Nginx.
                                 # Accepted values are `modern`,
                                 # `intermediate`, `old`, or `custom`.
                                 #
                                 # See https://wiki.mozilla.org/Security/Server_Side_TLS
                                 # for detailed descriptions of each cipher
                                 # suite.

#ssl_ciphers =                   # Defines a custom list of TLS ciphers to be
                                 # served by Nginx. This list must conform to
                                 # the pattern defined by `openssl ciphers`.
                                 # This value is ignored if `ssl_cipher_suite`
                                 # is not `custom`.

#ssl_cert =                      # The absolute path to the SSL certificate for
                                 # `proxy_listen` values with SSL enabled.

#ssl_cert_key =                  # The absolute path to the SSL key for
                                 # `proxy_listen` values with SSL enabled.

#client_ssl = off                # Determines if Nginx should send client-side
                                 # SSL certificates when proxying requests.

#client_ssl_cert =               # If `client_ssl` is enabled, the absolute
                                 # path to the client SSL certificate for the
                                 # `proxy_ssl_certificate` directive. Note that
                                 # this value is statically defined on the
                                 # node, and currently cannot be configured on
                                 # a per-API basis.

#client_ssl_cert_key =           # If `client_ssl` is enabled, the absolute
                                 # path to the client SSL key for the
                                 # `proxy_ssl_certificate_key` address. Note
                                 # this value is statically defined on the
                                 # node, and currently cannot be configured on
                                 # a per-API basis.

#admin_ssl_cert =                # The absolute path to the SSL certificate for
                                 # `admin_listen` values with SSL enabled.

#admin_ssl_cert_key =            # The absolute path to the SSL key for
                                 # `admin_listen` values with SSL enabled.

#headers = server_tokens, latency_tokens
                                 # Comma-separated list of headers Kong should
                                 # inject in client responses.
                                 #
                                 # Accepted values are:
                                 # - `Server`: Injects `Server: kong/x.y.z`
                                 #   on Kong-produced response (e.g. Admin
                                 #   API, rejected requests from auth plugin).
                                 # - `Via`: Injects `Via: kong/x.y.z` for
                                 #   successfully proxied requests.
                                 # - `X-Kong-Proxy-Latency`: Time taken
                                 #   (in milliseconds) by Kong to process
                                 #   a request and run all plugins before
                                 #   proxying the request upstream.
                                 # - `X-Kong-Response-Latency`: time taken
                                 #   (in millisecond) by Kong to produce
                                 #   a response in case of e.g. plugin
                                 #   short-circuiting the request, or in
                                 #   in case of an error.
                                 # - `X-Kong-Upstream-Latency`: Time taken
                                 #   (in milliseconds) by the upstream
                                 #   service to send response headers.
                                 # - `X-Kong-Admin-Latency`: Time taken
                                 #   (in milliseconds) by Kong to process
                                 #   an Admin API request.
                                 # - `X-Kong-Upstream-Status`: The HTTP status
                                 #   code returned by the upstream service.
                                 #   This is particularly useful for clients to
                                 #   distinguish upstream statuses if the
                                 #   response is rewritten by a plugin.
                                 # - `server_tokens`: Same as specifying both
                                 #   `Server` and `Via`.
                                 # - `latency_tokens`: Same as specifying
                                 #   `X-Kong-Proxy-Latency`,
                                 #   `X-Kong-Response-Latency`,
                                 #   `X-Kong-Admin-Latency` and
                                 #   `X-Kong-Upstream-Latency`
                                 #
                                 # In addition to those, this value can be set
                                 # to `off`, which prevents Kong from injecting
                                 # any of the above headers. Note that this
                                 # does not prevent plugins from injecting
                                 # headers of their own.
                                 #
                                 # Example: `headers = via, latency_tokens`

#trusted_ips =                   # Defines trusted IP addresses blocks that are
                                 # known to send correct `X-Forwarded-*`
                                 # headers.
                                 # Requests from trusted IPs make Kong forward
                                 # their `X-Forwarded-*` headers upstream.
                                 # Non-trusted requests make Kong insert its
                                 # own `X-Forwarded-*` headers.
                                 #
                                 # This property also sets the
                                 # `set_real_ip_from` directive(s) in the Nginx
                                 # configuration. It accepts the same type of
                                 # values (CIDR blocks) but as a
                                 # comma-separated list.
                                 #
                                 # To trust *all* /!\ IPs, set this value to
                                 # `<IP_ADDRESS>/0,::/0`.
                                 #
                                 # If the special value `unix:` is specified,
                                 # all UNIX-domain sockets will be trusted.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_realip_module.html#set_real_ip_from
                                 # for examples of accepted values.

#real_ip_header = X-Real-IP      # Defines the request header field whose value
                                 # will be used to replace the client address.
                                 # This value sets the `ngx_http_realip_module`
                                 # directive of the same name in the Nginx
                                 # configuration.
                                 #
                                 # If this value receives `proxy_protocol`:
                                 #
                                 # - at least one of the `proxy_listen` entries
                                 #   must have the `proxy_protocol` flag
                                 #   enabled.
                                 # - the `proxy_protocol` parameter will be
                                 #   appended to the `listen` directive of the
                                 #   Nginx template.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_header
                                 # for a description of this directive.

#real_ip_recursive = off         # This value sets the `ngx_http_realip_module`
                                 # directive of the same name in the Nginx
                                 # configuration.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_recursive
                                 # for a description of this directive.

#client_max_body_size = 0        # Defines the maximum request body size allowed
                                 # by requests proxied by Kong, specified in
                                 # the Content-Length request header. If a
                                 # request exceeds this limit, Kong will
                                 # respond with a 413 (Request Entity Too
                                 # Large). Setting this value to 0 disables
                                 # checking the request body size.

# See http://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size
# for further description of this parameter. Numeric values may be suffixed
# with `k` or `m` to denote limits in terms of kilobytes or megabytes.

#client_body_buffer_size = 8k    # Defines the buffer size for reading the
                                 # request body. If the client request body is
                                 # larger than this value, the body will be
                                 # buffered to disk. Note that when the body is
                                 # buffered to disk Kong plugins that access or
                                 # manipulate the request body may not work, so
                                 # it is advisable to set this value as high as
                                 # possible (e.g., set it as high as
                                 # `client_max_body_size` to force request
                                 # bodies to be kept in memory). Do note that
                                 # high-concurrency environments will require
                                 # significant memory allocations to process
                                 # many concurrent large request bodies.

# See http://nginx.org/en/docs/http/ngx_http_core_module.html#client_body_buffer_size
# for further description of this parameter. Numeric values may be suffixed
# with `k` or `m` to denote limits in terms of kilobytes or megabytes.

#error_default_type = text/plain  # Default MIME type to use when the request
                                  # `Accept` header is missing and Nginx
                                  # is returning an error for the request.
                                  # Accepted values are `text/plain`,
                                  # `text/html`, `application/json`, and
                                  # `application/xml`.

#------------------------------------------------------------------------------
# NGINX injected directives
#------------------------------------------------------------------------------

# Nginx directives can be dynamically injected in the runtime nginx.conf file
# without requiring a custom Nginx configuration template.
#
# All configuration properties respecting the naming scheme
# `nginx_<namespace>_<directive>` will result in `<directive>` being injected in
# the Nginx configuration block corresponding to the property's `<namespace>`.
# Example:
#   `nginx_proxy_large_client_header_buffers = 8 24k`
#
#   Will inject the following directive in Kong's proxy `server {}` block:
#
#   `large_client_header_buffers 8 24k;`
#
# The following namespaces are supported:
#
# - `nginx_main_<directive>`: Injects `<directive>` in Kong's configuration
#   `main` context.
# - `nginx_events_<directive>`: Injects `<directive>` in Kong's `events {}`
#    block.
# - `nginx_http_<directive>`: Injects `<directive>` in Kong's `http {}` block.
# - `nginx_proxy_<directive>`: Injects `<directive>` in Kong's proxy
#   `server {}` block.
# - `nginx_upstream_<directive>`: Injects `<directive>` in Kong's proxy
#   `upstream {}` block.
# - `nginx_admin_<directive>`: Injects `<directive>` in Kong's Admin API
#   `server {}` block.
# - `nginx_status_<directive>`: Injects `<directive>` in Kong's Status API
#   `server {}` block  (only effective if `status_listen` is enabled).
# - `nginx_stream_<directive>`: Injects `<directive>` in Kong's stream module
#   `stream {}` block (only effective if `stream_listen` is enabled).
# - `nginx_sproxy_<directive>`: Injects `<directive>` in Kong's stream module
#   `server {}` block (only effective if `stream_listen` is enabled).
# - `nginx_supstream_<directive>`: Injects `<directive>` in Kong's stream
#   module `upstream {}` block.
#
# As with other configuration properties, Nginx directives can be injected via
# environment variables when capitalized and prefixed with `KONG_`.
# Example:
#   `KONG_NGINX_HTTP_SSL_PROTOCOLS` -> `nginx_http_ssl_protocols`
#
#   Will inject the following directive in Kong's `http {}` block:
#
#   `ssl_protocols <value>;`
#
#   If different sets of protocols are desired between the proxy and Admin API
#   server, you may specify `nginx_proxy_ssl_protocols` and/or
#   `nginx_admin_ssl_protocols`, both of which taking precedence over the
#   `http {}` block.

#nginx_http_ssl_protocols = TLSv1.1 TLSv1.2 TLSv1.3
                                 # Enables the specified protocols for
                                 # client-side connections. The set of
                                 # supported protocol versions also depends
                                 # on the version of OpenSSL Kong was built
                                 # with.
                                 #
                                 # This value is ignored if `ssl_cipher_suite`
                                 # is not `custom`.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_protocols

#nginx_http_ssl_prefer_server_ciphers = on
                                 # Specifies that server ciphers should be
                                 # preferred over client ciphers when using
                                 # the SSLv3 and TLS protocols
                                 #
                                 # This value is ignored if `ssl_cipher_suite`
                                 # is not `custom`.
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_prefer_server_ciphers

#nginx_http_ssl_session_tickets = on
                                 # Enables or disables session resumption through
                                 # TLS session tickets. This is has no impact when
                                 # used with TLSv1.3.
                                 #
                                 # Kong enables this by default for performance
                                 # reasons, but it has security implications:
                                 # https://github.com/mozilla/server-side-tls/issues/135
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_tickets

#nginx_http_ssl_session_timeout = 1d
                                 # Specifies a time during which a client may
                                 # reuse the session parameters. See the rationale:
                                 # https://github.com/mozilla/server-side-tls/issues/198
                                 #
                                 # See http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_timeout

#nginx_upstream_keepalive = 60   # Sets the maximum number of idle keepalive
                                 # connections to upstream servers that are
                                 # preserved in the cache of each worker
                                 # process. When this number is exceeded, the
                                 # least recently used connections are closed.
                                 # A value of `NONE` will disable this behavior
                                 # altogether, forcing each upstream request
                                 # to open a new connection.
                                 # See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive

#nginx_upstream_keepalive_requests = 100
                                 # Sets the maximum number of requests that can
                                 # be served through one keepalive connection.
                                 # After the maximum number of requests is
                                 # made, the connection is closed.
                                 # See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive_requests

#nginx_upstream_keepalive_timeout = 60s
                                 # Sets a timeout during which an idle
                                 # keepalive connection to an upstream server
                                 # will stay open.
                                 # See http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive_timeout

#------------------------------------------------------------------------------
# DATASTORE
#------------------------------------------------------------------------------

# Kong can run with a database to store coordinated data between Kong nodes in
# a cluster, or without a database, where each node stores its information
# independently in memory.
#
# When using a database, Kong will store data for all its entities (such as
# Routes, Services, Consumers, and Plugins) in either Cassandra or PostgreSQL,
# and all Kong nodes belonging to the same cluster must connect themselves
# to the same database.
#
# Kong supports the following database versions:
# - **PostgreSQL**: 9.5 and above.
# - **Cassandra**: 2.2 and above.
#
# When not using a database, Kong is said to be in "DB-less mode": it will keep
# its entities in memory, and each node needs to have this data entered via a
# declarative configuration file, which can be specified through the
# `declarative_config` property, or via the Admin API using the `/config`
# endpoint.

database = postgres             # Determines which of PostgreSQL or Cassandra
                                 # this node will use as its datastore.
                                 # Accepted values are `postgres`,
                                 # `cassandra`, and `off`.

pg_host = <IP_ADDRESS>             # Host of the Postgres server.
pg_port = 5432                  # Port of the Postgres server.
pg_timeout = 5000               # Defines the timeout (in ms), for connecting,
                                 # reading and writing.

pg_user = kong                  # Postgres user.
pg_password = kong                   # Postgres user's password.
pg_database = kong              # The database name to connect to.

#pg_schema =                     # The database schema to use. If unspecified,
                                 # Kong will respect the `search_path` value of
                                 # your PostgreSQL instance.

#pg_ssl = off                    # Toggles client-server TLS connections
                                 # between Kong and PostgreSQL.

#pg_ssl_verify = off             # Toggles server certificate verification if
                                 # `pg_ssl` is enabled.
                                 # See the `lua_ssl_trusted_certificate`
                                 # setting to specify a certificate authority.

#pg_max_concurrent_queries = 0   # Sets the maximum number of concurrent queries
                                 # that can be executing at any given time. This
                                 # limit is enforced per worker process; the
                                 # total number of concurrent queries for this
                                 # node will be will be:
                                 # `pg_max_concurrent_queries * nginx_worker_processes`.
                                 #
                                 # The default value of 0 removes this
                                 # concurrency limitation.

#pg_semaphore_timeout = 60000    # Defines the timeout (in ms) after which
                                 # PostgreSQL query semaphore resource
                                 # acquisition attempts will fail. Such
                                 # failures will generally result in the
                                 # associated proxy or Admin API request
                                 # failing with an HTTP 500 status code.
                                 # Detailed discussion of this behavior is
                                 # available in the online documentation.

#cassandra_contact_points = <IP_ADDRESS>  # A comma-separated list of contact
                                       # points to your cluster.
                                       # You may specify IP addresses or
                                       # hostnames. Note that the port
                                       # component of SRV records will be
                                       # ignored in favor of `cassandra_port`.
                                       # When connecting to a multi-DC cluster,
                                       # ensure that contact points from the
                                       # local datacenter are specified first
                                       # in this list.

#cassandra_port = 9042           # The port on which your nodes are listening
                                 # on. All your nodes and contact points must
                                 # listen on the same port. Will be created if
                                 # it doesn't exist.

#cassandra_keyspace = kong       # The keyspace to use in your cluster.

#cassandra_consistency = ONE     # Consistency setting to use when reading/
                                 # writing to the Cassandra cluster.
                                 #
#cassandra_timeout = 5000        # Defines the timeout (in ms) for reading
                                 # and writing.

#cassandra_ssl = off             # Toggles client-to-node TLS connections
                                 # between Kong and Cassandra.

#cassandra_ssl_verify = off      # Toggles server certificate verification if
                                 # `cassandra_ssl` is enabled.
                                 # See the `lua_ssl_trusted_certificate`
                                 # setting to specify a certificate authority.

#cassandra_username = kong       # Username when using the
                                 # `PasswordAuthenticator` scheme.

#cassandra_password =            # Password when using the
                                 # `PasswordAuthenticator` scheme.

#cassandra_lb_policy = RequestRoundRobin  # Load balancing policy to use when
                                          # distributing queries across your
                                          # Cassandra cluster.
                                          # Accepted values are:
                                          # `RoundRobin`, `RequestRoundRobin`,
                                          # `DCAwareRoundRobin`, and
                                          # `RequestDCAwareRoundRobin`.
                                          # Policies prefixed with "Request"
                                          # make efficient use of established
                                          # connections throughout the same
                                          # request.
                                          # Prefer "DCAware" policies if and
                                          # only if you are using a
                                          # multi-datacenter cluster.

#cassandra_local_datacenter =    # When using the `DCAwareRoundRobin`
                                 # or `RequestDCAwareRoundRobin` load
                                 # balancing policy, you must specify the name
                                 # of the local (closest) datacenter for this
                                 # Kong node.

#cassandra_refresh_frequency = 60          # Frequency (in seconds) at which
                                           # the cluster topology will be
                                           # checked for new or decommissioned
                                           # nodes.
                                           # A value of `0` will disable this
                                           # check, and the cluster topology
                                           # will never be refreshed.

#cassandra_repl_strategy = SimpleStrategy  # When migrating for the first time,
                                           # Kong will use this setting to
                                           # create your keyspace.
                                           # Accepted values are
                                           # `SimpleStrategy` and
                                           # `NetworkTopologyStrategy`.

#cassandra_repl_factor = 1       # When migrating for the first time, Kong
                                 # will create the keyspace with this
                                 # replication factor when using the
                                 # `SimpleStrategy`.

#cassandra_data_centers = dc1:2,dc2:3  # When migrating for the first time,
                                       # will use this setting when using the
                                       # `NetworkTopologyStrategy`.
                                       # The format is a comma-separated list
                                       # made of `<dc_name>:<repl_factor>`.

#cassandra_schema_consensus_timeout = 10000  # Defines the timeout (in ms) for
                                             # the waiting period to reach a
                                             # schema consensus between your
                                             # Cassandra nodes.
                                             # This value is only used during
                                             # migrations.

#declarative_config =           # The path to the declarative configuration
                                # file which holds the specification of all
                                # entities (Routes, Services, Consumers, etc.)
                                # to be used when the `database` is set to
                                # `off`.
                                #
                                # Entities are stored in Kong's in-memory cache,
                                # so you must ensure that enough memory is
                                # allocated to it via the `mem_cache_size`
                                # property. You must also ensure that items
                                # in the cache never expire, which means that
                                # `db_cache_ttl` should preserve its default
                                # value of 0.

#------------------------------------------------------------------------------
# DATASTORE CACHE
#------------------------------------------------------------------------------

# In order to avoid unnecessary communication with the datastore, Kong caches
# entities (such as APIs, Consumers, Credentials...) for a configurable period
# of time. It also handles invalidations if such an entity is updated.
#
# This section allows for configuring the behavior of Kong regarding the
# caching of such configuration entities.

#db_update_frequency = 5         # Frequency (in seconds) at which to check for
                                 # updated entities with the datastore.
                                 #
                                 # When a node creates, updates, or deletes an
                                 # entity via the Admin API, other nodes need
                                 # to wait for the next poll (configured by
                                 # this value) to eventually purge the old
                                 # cached entity and start using the new one.

#db_update_propagation = 0       # Time (in seconds) taken for an entity in the
                                 # datastore to be propagated to replica nodes
                                 # of another datacenter.
                                 #
                                 # When in a distributed environment such as
                                 # a multi-datacenter Cassandra cluster, this
                                 # value should be the maximum number of
                                 # seconds taken by Cassandra to propagate a
                                 # row to other datacenters.
                                 #
                                 # When set, this property will increase the
                                 # time taken by Kong to propagate the change
                                 # of an entity.
                                 #
                                 # Single-datacenter setups or PostgreSQL
                                 # servers should suffer no such delays, and
                                 # this value can be safely set to 0.

#db_cache_ttl = 0                # Time-to-live (in seconds) of an entity from
                                 # the datastore when cached by this node.
                                 #
                                 # Database misses (no entity) are also cached
                                 # according to this setting.
                                 #
                                 # If set to 0 (default), such cached entities
                                 # or misses never expire.

#db_resurrect_ttl = 30           # Time (in seconds) for which stale entities
                                 # from the datastore should be resurrected for
                                 # when they cannot be refreshed (e.g., the
                                 # datastore is unreachable). When this TTL
                                 # expires, a new attempt to refresh the stale
                                 # entities will be made.

#db_cache_warmup_entities = services, plugins
                                 # Entities to be pre-loaded from the datastore
                                 # into the in-memory cache at Kong start-up.
                                 # This speeds up the first access of endpoints
                                 # that use the given entities.
                                 #
                                 # When the `services` entity is configured
                                 # for warmup, the DNS entries for values in
                                 # its `host` attribute are pre-resolved
                                 # asynchronously as well.
                                 #
                                 # Cache size set in `mem_cache_size` should
                                 # be set to a value large enough to hold all
                                 # instances of the specified entities.
                                 # If the size is insufficient, Kong will log
                                 # a warning.

#------------------------------------------------------------------------------
# DNS RESOLVER
#------------------------------------------------------------------------------

# By default the DNS resolver will use the standard configuration files
# `/etc/hosts` and `/etc/resolv.conf`. The settings in the latter file will be
# overridden by the environment variables `LOCALDOMAIN` and `RES_OPTIONS` if
# they have been set.
#
# Kong will resolve hostnames as either `SRV` or `A` records (in that order, and
# `CNAME` records will be dereferenced in the process).
# In case a name was resolved as an `SRV` record it will also override any given
# port number by the `port` field contents received from the DNS server.
#
# The DNS options `SEARCH` and `NDOTS` (from the `/etc/resolv.conf` file) will
# be used to expand short names to fully qualified ones. So it will first try
# the entire `SEARCH` list for the `SRV` type, if that fails it will try the
# `SEARCH` list for `A`, etc.
#
# For the duration of the `ttl`, the internal DNS resolver will loadbalance each
# request it gets over the entries in the DNS record. For `SRV` records the
# `weight` fields will be honored, but it will only use the lowest `priority`
# field entries in the record.

#dns_resolver =                  # Comma separated list of nameservers, each
                                 # entry in `ip[:port]` format to be used by
                                 # Kong. If not specified the nameservers in
                                 # the local `resolv.conf` file will be used.
                                 # Port defaults to 53 if omitted. Accepts
                                 # both IPv4 and IPv6 addresses.

#dns_hostsfile = /etc/hosts      # The hosts file to use. This file is read
                                 # once and its content is static in memory.
                                 # To read the file again after modifying it,
                                 # Kong must be reloaded.

#dns_order = LAST,SRV,A,CNAME    # The order in which to resolve different
                                 # record types. The `LAST` type means the
                                 # type of the last successful lookup (for the
                                 # specified name). The format is a (case
                                 # insensitive) comma separated list.

#dns_valid_ttl =                 # By default, DNS records are cached using
                                 # the TTL value of a response. If this
                                 # property receives a value (in seconds), it
                                 # will override the TTL for all records.

#dns_stale_ttl = 4               # Defines, in seconds, how long a record will
                                 # remain in cache past its TTL. This value
                                 # will be used while the new DNS record is
                                 # fetched in the background.
                                 # Stale data will be used from expiry of a
                                 # record until either the refresh query
                                 # completes, or the `dns_stale_ttl` number of
                                 # seconds have passed.

#dns_not_found_ttl = 30          # TTL in seconds for empty DNS responses and
                                 # "(3) name error" responses.

#dns_error_ttl = 1               # TTL in seconds for error responses.

#dns_no_sync = off               # If enabled, then upon a cache-miss every
                                 # request will trigger its own dns query.
                                 # When disabled multiple requests for the
                                 # same name/type will be synchronised to a
                                 # single query.

#------------------------------------------------------------------------------
# TUNING & BEHAVIOR
#------------------------------------------------------------------------------

#router_consistency = strict     # Defines whether this node should rebuild its
                                 # router synchronously or asynchronously (the
                                 # router is rebuilt every time a Route or a
                                 # Service is updated via the Admin API or
                                 # loading a declarative configuration file).
                                 #
                                 # Accepted values are:
                                 #
                                 # - `strict`: the router will be rebuilt
                                 #   synchronously, causing incoming requests to
                                 #   be delayed until the rebuild is finished.
                                 # - `eventual`: the router will be rebuilt
                                 #   asynchronously via a recurring background
                                 #   job running every second inside of each
                                 #   worker.
                                 #
                                 # Note that `strict` ensures that all workers
                                 # of a given node will always proxy requests
                                 # with an identical router, but that increased
                                 # long tail latency can be observed if
                                 # frequent Routes and Services updates are
                                 # expected.
                                 # Using `eventual` will help preventing long
                                 # tail latency issues in such cases, but may
                                 # cause workers to route requests differently
                                 # for a short period of time after Routes and
                                 # Services updates.

#router_update_frequency = 1     # Defines how often the router changes are
                                 # checked with a background job. When a change
                                 # is detected, a new router will be built. By
                                 # default we check for changes every second.
                                 # Raising this value will decrease the load on
                                 # database servers and result in less jitter
                                 # in proxy latency, with downside of longer
                                 # converge time for router updates.

#------------------------------------------------------------------------------
# DEVELOPMENT & MISCELLANEOUS
#------------------------------------------------------------------------------

# Additional settings inherited from lua-nginx-module allowing for more
# flexibility and advanced usage.
#
# See the lua-nginx-module documentation for more information:
# https://github.com/openresty/lua-nginx-module

#lua_ssl_trusted_certificate =   # Absolute path to the certificate
                                 # authority file for Lua cosockets in PEM
                                 # format. This certificate will be the one
                                 # used for verifying Kong's database
                                 # connections, when `pg_ssl_verify` or
                                 # `cassandra_ssl_verify` are enabled.
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_ssl_trusted_certificate

#lua_ssl_verify_depth = 1        # Sets the verification depth in the server
                                 # certificates chain used by Lua cosockets,
                                 # set by `lua_ssl_trusted_certificate`.
                                 # This includes the certificates configured
                                 # for Kong's database connections.
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_ssl_verify_depth

#lua_package_path = ./?.lua;./?/init.lua;  # Sets the Lua module search path
                                           # (LUA_PATH). Useful when developing
                                           # or using custom plugins not stored
                                           # in the default search path.
                                           #
                                           # See https://github.com/openresty/lua-nginx-module#lua_package_path

#lua_package_cpath =             # Sets the Lua C module search path
                                 # (LUA_CPATH).
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_package_cpath

#lua_socket_pool_size = 30       # Specifies the size limit for every cosocket
                                 # connection pool associated with every remote
                                 # server.
                                 #
                                 # See https://github.com/openresty/lua-nginx-module#lua_socket_pool_size

Could you please provide us with the server status log?
$ systemctl status kong