Traefik 2.0 on Docker Host Network; Router will redirect instead of reverse proxy

[Ultradark]

Do you want to request a feature or report a bug?

Bug

Did you try using a 1.7.x configuration for the version 2.0?

• Yes
• No

What did you do?

I configured reverse proxy Pritunl website using Traefik 2.0.

What did you expect to see?

Pritunl website loading correctly.

What did you see instead?

On client side, I am being redirected to localhost url (127.0.0.1:5400/login) instead of server url example.com/login. This is working correctly in Traefik 1.7 backends.

Output of traefik version: (What version of Traefik are you using?)

Version:      2.0.0
Codename:     montdor
Go version:   go1.13
Built:        2019-09-16T17:35:17Z
OS/Arch:      linux/amd64

What is your environment & configuration (arguments, toml, provider, platform, ...)?

servers.yml

http:
  routers:
    vpn:
      rule: "Host(example.net)"
      service: vpn
      tls: {}

  services:
    vpn:
      loadBalancer:
        servers:
        - url: "https://127.0.0.1:5400/"

Docker-Compose.yml

version: '3.3'

services:
  reverse-proxy:
    image: traefik:latest # The official Traefik docker image
    command: --providers.docker
    ports:
      - "80:80"     # The HTTP port
      - "443:443"   # The HTTPS port
      - "8080:8080"   # Dashboard port
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock" # So that Traefik can listen to the Docker events
      - "./traefik.yml:/traefik.yml"
      - "./acme.json:/acme.json"
      - "./servers.yml:/servers.yml"
    labels:
      - "traefik.enable=true"
    network_mode: host
    restart: always

traefik.yml

global:
  checkNewVersion: false
  sendAnonymousUsage: false
serversTransport:
  insecureSkipVerify: true
entryPoints:
  web:
    address: ":80"
  websecure:
    address: ":443"
  traefik:
    address: ":8080"
providers:
  docker:
    watch: true
    endpoint: "unix:///var/run/docker.sock"
    defaultRule: "Host(`example.net`)"
  file:
    watch: true
    filename: "/servers.yml"
api:
  insecure: true
  dashboard: true
  debug: false
certificatesResolvers:
  account:
    acme:
      email: "example@example.org"
      storage: "/acme.json"
      httpChallenge:
        entryPoint: web
      tlsChallenge: {}

[andrewsav-bt]

To me it sounds more like a config issue rather than a traefik bug. I think the key question is this: it sounds like it's Pritunl does the redirection, not traefik (traefik would not know to redirect to /login since it does not appear anywhere in the configuration), so why Pritunl is redirecting to that address? When you find out this, you are likely to make progress in resolving this.

[traefiker]

Hi! I'm Træfiker 🤖 the bot in charge of communication regulation.

Thanks for your interest in Traefik!

We dedicate the issue tracker to bug reports and feature requests only. My advanced AI has spotted that your issue might be a configuration problem or relates to something that doesn't look like a bug.

To confirm this, please join our Community Forum and reach out to us on the Traefik section.

In case I'm wrong (well, that would be embarrassing 😅), my developers will re-open the issue and fix me!

In the meantime, you can double check Traefik's documentation.

[dduportal]

As @andrewsav-datacom said, the redirect looks triggered by the backend service, not by Traefik itself. Do you mind switching to the community forum to get further help from the community, as this is not a bug with Traefik itself. Thanks a lot for your understanding and helping us having a good issue triage!

[Ultradark]

Hello,

While not a bug, this issue is related to Traefik and its interface with services. For future reference, I have managed to find out the solution to this problem, which is enabling passHostHeader option.

http:
  routers:
    vpn:
      rule: "Host(example.net)"
      service: vpn
      tls: {}

  services:
    vpn:
      loadBalancer:
        passHostHeader: true
        servers:
        - url: "https://127.0.0.1:5400/"