Docker-compose basic example

In this section we quickly go over a basic docker-compose file exposing a simple service using the docker provider.
This will also be used as a starting point for the other docker-compose guides.

Setup

• Edit a docker-compose.yml file with the following content:

version: "3.3"

services:

  traefik:
    image: "traefik:v2.5"
    container_name: "traefik"
    command:
      #- "--log.level=DEBUG"
      - "--api.insecure=true"
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
      - "--entrypoints.web.address=:80"
    ports:
      - "80:80"
      - "8080:8080"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"

  whoami:
    image: "traefik/whoami"
    container_name: "simple-service"
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.whoami.rule=Host(`whoami.localhost`)"
      - "traefik.http.routers.whoami.entrypoints=web"

• Replace whoami.localhost by your own domain within the traefik.http.routers.whoami.rule label of the whoami service.
• Run docker-compose up -d within the folder where you created the previous file.

• Wait a bit and visit http://your_own_domain to confirm everything went fine. You should see the output of the whoami service. Something similar to:

  Hostname: d7f919e54651
  IP: 127.0.0.1
  IP: 192.168.64.2
  GET / HTTP/1.1
  Host: whoami.localhost
  User-Agent: curl/7.52.1
  Accept: */*
  Accept-Encoding: gzip
  X-Forwarded-For: 192.168.64.1
  X-Forwarded-Host: whoami.localhost
  X-Forwarded-Port: 80
  X-Forwarded-Proto: http
  X-Forwarded-Server: 7f0c797dbc51
  X-Real-Ip: 192.168.64.1

Details

• As an example we use whoami (a tiny Go server that prints os information and HTTP request to output) which was used to define our simple-service container.

• We define an entry point, along with the exposure of the matching port within docker-compose, which basically allow us to "open and accept" HTTP traffic:

command:
  # Traefik will listen to incoming request on the port 80 (HTTP)
  - "--entrypoints.web.address=:80"

ports:
  - "80:80"

• We expose the Traefik API to be able to check the configuration if needed:

command:
  # Traefik will listen on port 8080 by default for API request.
  - "--api.insecure=true"

ports:
  - "8080:8080"

Note

If you are working on a remote server, you can use the following command to display configuration (require curl & jq):

curl -s 127.0.0.1:8080/api/rawdata | jq .

• We allow Traefik to gather configuration from Docker:

traefik:
  command:
    # Enabling docker provider
    - "--providers.docker=true"
    # Do not expose containers unless explicitly told so
    - "--providers.docker.exposedbydefault=false"
  volumes:
    - "/var/run/docker.sock:/var/run/docker.sock:ro"

whoami:
  labels:
    # Explicitly tell Traefik to expose this container
    - "traefik.enable=true"
    # The domain the service will respond to
    - "traefik.http.routers.whoami.rule=Host(`whoami.localhost`)"
    # Allow request only from the predefined entry point named "web"
    - "traefik.http.routers.whoami.entrypoints=web"