Traefik

Traefik is a reverse Proxy that manages routing of services on a Server.

Getting started

Traefik is preferable used inside a Docker container.

Traefik docker-compose file:

version: '3.9'

services:
  reverse-proxy:
    image: traefik:v2.6
    restart: "always"
    # In this example traefik is configured with CLI options.
    # "--providers.docker=true": Enable Docker as a provider
    # "--providers.docker.network="traefik"" specify the docker network "traefik" as the network for traefik. This is option must be used when a container has two or more networks attached to it
    # "--api.insecure=true": enables traefiks dashboard
    command: --providers.docker=true --providers.docker.network="traefik" --api.insecure=true
    ports:
      # Open Port 80 & 443 for traefik
      - "80:80"
      - "443:443"
      # Open Port 8080 for traefiks webinterface
      - "8080:8080"
    volumes:
      # mount the docker socket, so that Traefik can listen to the Docker events
      - /var/run/docker.sock:/var/run/docker.sock
    networks:
      - traefik

networks:
  traefik:
    driver: "bridge"
    name: traefik

Webserver docker-compose file:

version: '3.9'
 
services:
  webserver:
    image: httpd:2.4.52-alpine
    restart: "always"
    expose:
      # If only one port is exposed traefik, will detect and use it
      - 80
    labels:
       # Rules for routing can be defined with labels. "traefik.http.routers.<Container name>.rule" tells traefik when to route to this container
      # In this case traefik will route to this webserver when the requested host is "example.com"
      - traefik.http.routers.webserver.rule=Host(`example.com`)
    networks:
      # Make sure to add this service to the same network as traefik
      - traefik
 
networks:
  traefik:
    external: true

Configuration

Traefik can be configured by either commandline options or a config file. A config file must be created under /etc/traefik/traefik.yml. This file can also be in TOML format. Also note that all config options and values are case sensitive.

Docker

Full documentation about this topic: Docker

providers.docker.exposedByDefault

Default value: true

If set to false all containers are ignored by default and must use the traefik.enable=true label to be not ignored by traefik. This is usefull if you have a lot of containers not exposing any ports.

providers.docker.network

Default value: <None>

This defines the docker network that should be used by traefik to connect to other containers. If a container uses more than the traefik network this option should be used. This can also be applied per-container with the traefik.docker.network label.

Logging

Full documentation about this topic: Access Logs & Logs

accessLog.filePath

Default value: <None>

Defines the file to write access logs. If this option is not used the access logs are written to standard output (StdOut).

accessLog.format

Default value: "CLF"

Access logs written in the "Common Log Format" (CLF) by default. It is also possable to write access logs as JSON, by setting the format to json. Note the access log file is not written as a valid JSON file but instead is written in JSON-Lines. If an Invalid format is provided traefik willl fallback to CLF.

log.filePath

Default value: <None>

Defines the file to write logs. If this option is not used the logs are written to standard output (StdOut).

log.format

Default value: "CLF"

Logs written in the "Common Log Format" (CLF) by default. It is also possable to write logs as JSON, by setting the format to json. Note the log file not in written as valid JSON file but instead is written in JSON-Lines. If an Invalid format is provided traefik willl fallback to CLF.

log.level

Default value: "ERROR"

This options sets the verbosity of the traefik logs. Valid values are: DEBUG, INFO, WARN, ERROR, FATAL & PANIC

Example Configuration File (YML)

api:
  dashboard: true
  insecure: true

entryPoints:
  web:
    address: ":80"
  websecure:
    address: ":443"

providers:
  docker:
    network: "traefik"

accesslog:
  filepath: "/opt/access.log"

log:
  filepath: "/opt/traefik.log"