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 the other docker-compose guides.

Setup

  • Edit a docker-compose.yml file with the following content:
  1. version: "3.3"
  3. services:
  5.   traefik:
  6.     image: "traefik:v2.0.0-rc3"
  7.     container_name: "traefik"
  8.     command:
  9.       #- "--log.level=DEBUG"
  10.       - "--api.insecure=true"
  11.       - "--providers.docker=true"
  12.       - "--providers.docker.exposedbydefault=false"
  13.       - "--entrypoints.web.address=:80"
  14.     ports:
  15.       - "80:80"
  16.       - "8080:8080"
  17.     volumes:
  18.       - "/var/run/docker.sock:/var/run/docker.sock:ro"
  20.   whoami:
  21.     image: "containous/whoami"
  22.     container_name: "simple-service"
  23.     labels:
  24.       - "traefik.enable=true"
  25.       - "traefik.http.routers.whoami.rule=Host(`whoami.localhost`)"
  26.       - "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:
  1. Hostname: d7f919e54651
  2. IP: 127.0.0.1
  3. IP: 192.168.64.2
  4. GET / HTTP/1.1
  5. Host: whoami.localhost
  6. User-Agent: curl/7.52.1
  7. Accept: */*
  8. Accept-Encoding: gzip
  9. X-Forwarded-For: 192.168.64.1
  10. X-Forwarded-Host: whoami.localhost
  11. X-Forwarded-Port: 80
  12. X-Forwarded-Proto: http
  13. X-Forwarded-Server: 7f0c797dbc51
  14. 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: 

  1. command:
  2.   # Traefik will listen to incoming request on the port 80 (HTTP)
  3.   - "--entrypoints.web.address=:80"
  5. ports:
  6.   - "80:80"
  • We expose the Traefik API to be able to check the configuration if needed:
  1. command:
  2.   # Traefik will listen on port 8080 by default for API request.
  3.   - "--api.insecure=true"
  5. ports:
  6.   - "8080:8080"

Note

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

  1. curl -s 127.0.0.1:8080/api/rawdata | jq .
  • We allow Traefik to gather configuration from Docker:
  1. traefik:
  2.   command:
  3.     # Enabling docker provider
  4.     - "--providers.docker=true"
  5.     # Do not expose containers unless explicitly told so
  6.     - "--providers.docker.exposedbydefault=false"
  7.   volumes:
  8.     - "/var/run/docker.sock:/var/run/docker.sock:ro"
  10. whoami:
  11.   labels:
  12.     # Explicitly tell Traefik to expose this container
  13.     - "traefik.enable=true"
  14.     # The domain the service will respond to
  15.     - "traefik.http.routers.whoami.rule=Host(`whoami.localhost`)"
  16.     # Allow request only from the predefined entry point named "web"
  17.     - "traefik.http.routers.whoami.entrypoints=web"