Multilogger Docker Logging Driver

Overview

This Docker plugins sends container logs to multiple destinations at once. These instructions are for Linux host systems. For other platforms, see the Docker Engine managed plugin system documentation.

If you have any questions or issues using the Docker plugin feel free to open an issue in this repository.

Plugin Installation

Install from the Docker store

Pull the plugin from the Docker Store

$ docker plugin install --alias multilogger:latest allgdante/docker-multilogger-plugin:0.0.2

Enable the plugin

$ docker plugin enable multilogger

Install from source

Clone the repository

$ cd docker-multilogger-plugin

Build the plugin

$ make all

Enable the plugin

$ docker plugin multilogger enable

Plugin Configuration

Configure the logging driver for a container

If multilogger is in use but no logging driver is selected, the json-file logging driver will be automatically enabled:

docker run \
    --log-driver=multilogger \
    nginx/stable-alpine

The following command configure the container to start with the multilogger driver which will send logs to gelf and syslog servers.

docker run \
    --log-driver=multilogger \
    --log-opt gelf-enabled=true \
    --log-opt gelf-address=udp://127.0.0.1:12201 \
    --log-opt syslog-enabled=true \
    --log-opt syslog-address=tcp://127.0.0.1:514 \
    nginx/stable-alpine

In the previous example, if we want to have the json-file logging driver enabled, it must be explicitly enabled like this:

docker run \
    --log-driver=multilogger \
    --log-opt json-file-enabled=true \
    --log-opt gelf-enabled=true \
    --log-opt gelf-address=udp://127.0.0.1:12201 \
    --log-opt syslog-enabled=true \
    --log-opt syslog-address=tcp://127.0.0.1:514 \
    nginx/stable-alpine

Configure the default logging driver

To configure the Docker daemon to default to multilogger logging driver, you must configure the file /etc/docker/daemon.json like this:

{
    "log-driver": "multilogger"
}

If we want to include options, it must be configured like this:

{
    "log-driver": "multilogger",
    "log-opts": {
        "multilogger-max-size": "2m",
        "json-file-enabled": "true",
        "gelf-enabled": "true",
        "gelf-address": "udp://127.0.0.1:12201",
        "syslog-enabled": "true",
        "syslog-address": "tcp:/127.0.0.1:514"
    }
}

This way, we will have a multilogger driver configured who writes to json, gelf, and syslog with a maximum log line of 2 MB.

Available options and logging drivers

Multilogger logging driver

Option	Description
`multilogger-max-size`	The maximum size of a log message before it is send to the configured drivers. A positive integer plus a modifier representing the unit of measure (k, m, or g). Defaults to `2 >> 20`.

JSON File logging driver

Refer to the official documentation for more details. Note that this logging driver is always enabled if multilogger driver is selected and no logging driver is enabled

Option	Description
`json-file-enabled`	To enable this driver, use `true` here.
`max-size`	Same as Docker.
`max-file`	Same as Docker.
`labels`	Same as Docker.
`labels-regex`	Same as Docker.
`env`	Same as Docker.
`env-regex`	Same as Docker.
`compress`	Same as Docker.
`tag`	Same as Docker.
`json-file-log-dir`	`/var/log/docker`