How to get traefik to redirect to specific non-docker port from inside docker

Question

First of all I'm sorry if I'm not using the right terms to ask this question, but I'm not up to the terminology in place.

I have traefik running in a docker container and serving some services with the PathPrefix option, for instance, www.myserver.com/wordpress redirects to a docker container running wordpress.

But how do I get it to redirect to outside a docker container? Specifically, how do I get www.myserver.com to redirect to port 8080 in my machine to serve a service I have running there in the host OS (not in a docker container)?

This is my traefik.toml:

logLevel = "DEBUG"
defaultEntryPoints = ["http", "https"]

[entryPoints]
    [entryPoints.http]
        address = ":80"
        compress = false
        [entryPoints.http.redirect]
            entryPoint = "https"
    [entryPoints.https]
        address = ":443"
        [entryPoints.https.tls]

[acme]
email = "[email protected]"
storage = "acme.json"
entryPoint = "https"
onHostRule = true
#onDemand = true
[[acme.domains]]
    main = "www.myserver.com"

[web]
address = ":8888"

[docker]
endpoint = "unix:///var/run/docker.sock"
domain = "www.myserver.com"
watch = true
exposedbydefault = false

And my docker-compose.yml for the traefik container:

version: "2"

services:
  traefik:
    image: traefik
    network_mode: "host"
    ports:
      - "80:80"
      - "443:443"
      - "8888:8888"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ${SERVER_DIR}/AppData/traefik:/etc/traefik/
      - ${PWD}/acme.json:/acme.json
      - ${PWD}/traefik.toml:/etc/traefik/traefik.toml
      - ${PWD}/servers.toml:/etc/traefik/servers.toml
    restart: never

Answer 1

With the new Traefik (v.2) you need to use a combination of labels and an external file, you can find below my working example.

In your docker compose you need to add the comands to define the external file and enable the provider

  - "--providers.file=true"
  - "--providers.file.filename=/etc/traefik/rules.toml"

Into your file (rules.toml) the routing to foward to your external service (be aware of the syntax, use the char to define the host ( ` ) )

example :

Docker-compose:

  traefik:
    image: "traefik:v2.0.0"
    container_name: "traefik"
    restart: always
    command:
      - "--api.insecure=true"
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=false"
      - "--entrypoints.web.address=:80"
      - "--entrypoints.websecure.address=:443"
      - "--certificatesresolvers.myhttpchallenge.acme.httpchallenge=true"
      - "--certificatesresolvers.myhttpchallenge.acme.httpchallenge.entrypoint=web"
      - "[email protected]"
      - "--providers.file=true"
      - "--providers.file.filename=/etc/traefik/rules.toml"
      - "--providers.docker=true"
      - "--providers.file.watch=true"
    ports:
      - "80:80"
      - "8080:8080"
      - "443:443"
    networks:
      - proxy
    environment:
      - CF_API_EMAIL="xx"
      - CF_API_KEY="xx"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "./traefik/rules.toml:/etc/traefik/rules.toml"

Rules.toml

  [http.routers]
   # Define a connection between requests and services
     [http.routers.nasweb]
        rule = "Host(`nas.xxxx.com`)"
        entrypoints = ["websecure"]
        service = "nas"
     [http.routers.nasweb.tls]
        certResolver = "myhttpchallenge"


 [http.services]
        # Define how to reach an existing service on our infrastructure
        [http.services.nas.loadBalancer]
           [[http.services.nas.loadBalancer.servers]]
             url = "http://192.168.0.165:80"