File Log plugin

Append request and response data in JSON format to a log file. You can also specify streams (for example, /dev/stdout and /dev/stderr), which is especially useful when running Kong in Kubernetes.

This plugin uses blocking I/O, which could affect performance when writing to physical files on slow (spinning) disks.

Configuration Reference

This plugin is compatible with requests with the following protocols:

http
https
grpc
grpcs
tcp
tls
udp

This plugin is compatible with DB-less mode.

In DB-less mode, Kong Gateway does not have an Admin API. If using this mode, configure the plugin using declarative configuration.

Enabling the plugin on a Service

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin on a Service by making the following request:

$ curl -X POST http://<admin-hostname>:8001/services/<service>/plugins \
    --data "name=file-log"  \
    --data "config.path=/tmp/file.log" \
    --data "config.reopen=false"

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <file-log-example>
config: 
  path: /tmp/file.log
  reopen: false
plugin: file-log

Next, apply the KongPlugin resource to a Service by annotating the Service as follows:

apiVersion: v1
kind: Service
metadata:
  name: <service>
  labels:
    app: <service>
  annotations:
    konghq.com/plugins: <file-log-example>
spec:
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    name: <service>
  selector:
    app: <service>

Note: The KongPlugin resource only needs to be defined once and can be applied to any Service, Consumer, or Route in the namespace. If you want the plugin to be available cluster-wide, create the resource as a KongClusterPlugin instead of KongPlugin.

For example, configure this plugin on a Service by adding this section to your declarative configuration file:

plugins:
- name: file-log
  service: <service>
  config: 
    path: /tmp/file.log
    reopen: false

<service> is the id or name of the Service that this plugin configuration will target.

Enabling the plugin on a Route

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin on a Route with:

$ curl -X POST http://<admin-hostname>:8001/routes/<route>/plugins \
    --data "name=file-log"  \
    --data "config.path=/tmp/file.log" \
    --data "config.reopen=false"

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <file-log-example>
config: 
  path: /tmp/file.log
  reopen: false
plugin: file-log

Then, apply it to an ingress (Route or Routes) by annotating the ingress as follows:

apiVersion: networking/v1beta1
kind: Ingress
metadata:
  name: <route>
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/plugins: <file-log-example>
spec:
  rules:
  - host: examplehostname.com
    http:
      paths:
      - path: /bar
        backend:
          serviceName: echo
          servicePort: 80

For example, configure this plugin on a Route by adding this section to your declarative configuration file:

plugins:
- name: file-log
  route: <route>
  config: 
    path: /tmp/file.log
    reopen: false

<route> is the id or name of the Route that this plugin configuration will target.

Enabling the plugin on a Consumer

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin on a Consumer with:

$ curl -X POST http://<admin-hostname>:8001/consumers/<consumer>/plugins \
    --data "name=file-log"  \
    --data "config.path=/tmp/file.log" \
    --data "config.reopen=false"

You can combine consumer.id, service.id, or route.id in the same request, to further narrow the scope of the plugin.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <file-log-example>
config: 
  path: /tmp/file.log
  reopen: false
plugin: file-log

Then, apply it to a Consumer by annotating the KongConsumer resource as follows:

apiVersion: configuration.konghq.com/v1
kind: KongConsumer
metadata:
  name: <consumer>
  annotations:
    konghq.com/plugins: <file-log-example>
    kubernetes.io/ingress.class: kong

For example, configure this plugin on a Consumer by adding this section to your declarative configuration file:

plugins:
- name: file-log
  consumer: <consumer>
  config: 
    path: /tmp/file.log
    reopen: false

<consumer> is the id or username of the Consumer that this plugin configuration will target.

Enabling the plugin globally

A plugin which is not associated to any Service, Route, or Consumer is considered global, and will be run on every request. Read the Plugin Reference and the Plugin Precedence sections for more information.

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin globally with:

$ curl -X POST http://<admin-hostname>:8001/plugins/ \
    --data "name=file-log"  \
    --data "config.path=/tmp/file.log" \
    --data "config.reopen=false"

Create a KongClusterPlugin resource and label it as global:

apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
  name: <global-file-log>
  annotations:
    kubernetes.io/ingress.class: kong
  labels:
    global: \"true\"
config: 
  path: /tmp/file.log
  reopen: false
plugin: file-log

For example, configure this plugin using the plugins: entry in the declarative configuration file:

plugins:
- name: file-log
  config: 
    path: /tmp/file.log
    reopen: false

Parameters

Here's a list of all the parameters which can be used in this plugin's configuration:

Form Parameter	Description
`name` Type: string	The name of the plugin to use, in this case `file-log`.
`service.id` Type: string	The ID of the Service the plugin targets.
`route.id` Type: string	The ID of the Route the plugin targets.
`consumer.id` Type: string	The ID of the Consumer the plugin targets.
`enabled` Type: boolean Default value: `true`	Whether this plugin will be applied.
`config.path` required Type: string	The file path of the output log file. The plugin creates the log file if it doesn’t exist yet. Make sure Kong has write permissions to this file.
`config.reopen` required Type: boolean Default value: false	Determines whether the log file is closed and reopened on every request. If the file is not reopened, and has been removed/rotated, the plugin keeps writing to the stale file descriptor, and hence loses information.

Log Format

Every request will be logged separately in a JSON object separated by a new line \n, with the following format:

{
    "request": {
        "method": "GET",
        "uri": "/get",
        "url": "http://httpbin.org:8000/get",
        "size": "75",
        "querystring": {},
        "headers": {
            "accept": "*/*",
            "host": "httpbin.org",
            "user-agent": "curl/7.37.1"
        },
        "tls": {
            "version": "TLSv1.2",
            "cipher": "ECDHE-RSA-AES256-GCM-SHA384",
            "supported_client_ciphers": "ECDHE-RSA-AES256-GCM-SHA384",
            "client_verify": "NONE"
        }
    },
    "upstream_uri": "/",
    "response": {
        "status": 200,
        "size": "434",
        "headers": {
            "Content-Length": "197",
            "via": "kong/0.3.0",
            "Connection": "close",
            "access-control-allow-credentials": "true",
            "Content-Type": "application/json",
            "server": "nginx",
            "access-control-allow-origin": "*"
        }
    },
    "tries": [
        {
            "state": "next",
            "code": 502,
            "ip": "127.0.0.1",
            "port": 8000
        },
        {
            "ip": "127.0.0.1",
            "port": 8000
        }
    ],
    "authenticated_entity": {
        "consumer_id": "80f74eef-31b8-45d5-c525-ae532297ea8e",
        "id": "eaa330c0-4cff-47f5-c79e-b2e4f355207e"
    },
    "route": {
        "created_at": 1521555129,
        "hosts": null,
        "id": "75818c5f-202d-4b82-a553-6a46e7c9a19e",
        "methods": null,
        "paths": [
            "/example-path"
        ],
        "preserve_host": false,
        "protocols": [
            "http",
            "https"
        ],
        "regex_priority": 0,
        "service": {
            "id": "0590139e-7481-466c-bcdf-929adcaaf804"
        },
        "strip_path": true,
        "updated_at": 1521555129
    },
    "service": {
        "connect_timeout": 60000,
        "created_at": 1521554518,
        "host": "example.com",
        "id": "0590139e-7481-466c-bcdf-929adcaaf804",
        "name": "myservice",
        "path": "/",
        "port": 80,
        "protocol": "http",
        "read_timeout": 60000,
        "retries": 5,
        "updated_at": 1521554518,
        "write_timeout": 60000
    },
    "workspaces": [
        {
            "id":"b7cac81a-05dc-41f5-b6dc-b87e29b6c3a3",
            "name": "default"
        }
    ],
    "consumer": {
        "username": "demo",
        "created_at": 1491847011000,
        "id": "35b03bfc-7a5b-4a23-a594-aa350c585fa8"
    },
    "latencies": {
        "proxy": 1430,
        "kong": 9,
        "request": 1921
    },
    "client_ip": "127.0.0.1",
    "started_at": 1433209822425
}

A few considerations on the above JSON object:

request contains properties about the request sent by the client
response contains properties about the response sent to the client
tries contains the list of (re)tries (successes and failures) made by the load balancer for this request
route contains Kong properties about the specific Route requested
service contains Kong properties about the Service associated with the requested Route
authenticated_entity contains Kong properties about the authenticated credential (if an authentication plugin has been enabled)
workspaces contains Kong properties of the Workspaces associated with the requested Route. Only in Kong Enterprise version >= 0.34.
consumer contains the authenticated Consumer (if an authentication plugin has been enabled)
latencies contains some data about the latencies involved:
- proxy is the time it took for the final service to process the request
- kong is the internal Kong latency that it took to run all the plugins
- request is the time elapsed between the first bytes were read from the client and after the last bytes were sent to the client. Useful for detecting slow clients.
client_ip contains the original client IP address
started_at contains the UTC timestamp of when the request has started to be processed.

Kong Process Errors

This logging plugin logs HTTP request and response data, and also supports streams data (TCP, TLS, and UDP).

If you are looking for the Kong process error file (which is the nginx error file), you can find it at the following path:

{prefix}/logs/error.log

About this Plugin
Made by
Categories	Logging
DB-less compatible?	Yes (Kong Gateway (OSS) only)
Version Compatibility
Kong Gateway (Enterprise) 2.3.x 2.2.x 2.1.x 1.5.x 1.3-x 0.36-x Kong Gateway (OSS) 2.3.x 2.2.x 2.1.x 2.0.x 1.5.x 1.4.x 1.3.x 1.2.x 1.1.x 1.0.x 0.14.x 0.13.x 0.12.x 0.11.x 0.10.x 0.9.x 0.8.x 0.7.x 0.6.x 0.5.x 0.4.x 0.3.x