TrueNAS Scale 2: Electic Eel-aloo ft Traefik

Now, jellyfin-ix-jellyfin isn't especially pleasant. We could use docker labels to specify a hostname, but a) not every TrueNAS app lets you add labels and b) we want to do less manual work! Instead, we can set up a defaultRule. The docs say:

It must be a valid Go template, and can use sprig template functions. The container name can be accessed with the ContainerName identifier. The service name can be accessed with the Name identifier.

With a little regex magic, we can make our labels a little nicer:

services:
  traefik:
    environment:
      TRAEFIK_PROVIDERS_DOCKER_DEFAULTRULE: >-
         {{ regexReplaceAll "([a-z-]+)-ix.*" .Name
           "Host(`$1.montero.house.local`) || Host(`$1.montero`)" }}

And here we go! Accessible exactly as we want!

$ curl -I http://jellyfin.montero/web/
HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: 9723
Content-Type: text/html
Date: Mon, 02 Dec 2024 06:11:05 GMT
Etag: "1db3a353dad17fb"
Last-Modified: Tue, 19 Nov 2024 03:43:48 GMT
Server: Kestrel
X-Response-Time-Ms: 0.1094

Now, this doesn't always work perfectly. Plex, for example, exposes multiple ports, so Traefik needs a little help to find the right one. We do this with a Docker Label:

traefik.http.services.plex.loadbalancer.server.port=32000

For docker-compose services, we can just drop in labels files directly, especially if they don't match the ix scheme:

labels:
- traefik.http.services.transmission.loadbalancer.server.port=9001
- >-
  traefik.http.routers.transmission.rule=Host(`transmission.montero.house.local`)
  || Host(`transmission.montero`)

Ideally, we could access the TrueNAS web interface through our proxy as well. truenas.montero ought to work, at least if we're not futzing with the router.

But TrueNAS doesn't run in Docker, so our regular discovery mechanism doesn't work.

The solution I settled on is… inelegant, but servicable.

Traefik has two kinds of configuration: Static configuration and dynamic configuration. We're using env variables to control static configuration: what port to serve on, how to name services, other stuff that won't change.

But "services" (Traefik backend servers) and "routers" (Frontend rule sets) are dynamic. So even though ours won't change, we need to use a dynamic configuration provider.

The only manual ones available File and HTTP. Thus, to add our special case entry, we need to create a file.

Here's our basic declaration:

http:
  services:
    TrueNAS:
      loadbalancer:
        servers:
        - url: http://192.168.6.66:8080
  routers:
    TrueNAS:
      entrypoints:
      - http
      service: TrueNAS
      rule: "Host(`truenas.montero`) || Host(`truenas.montero.house.local`)"

We'll make use of Docker Compose configs.

services:
  traefik:
    environment:
      TRAEFIK_PROVIDERS_FILE_FILENAME: '/tmp/traefik-truenas.yaml'
    configs:
    - source: truenas_config
      target: '/tmp/traefik-truenas.yaml'
configs:
  truenas_config:
    content: |
      http:
        services:
          TrueNAS:
            loadbalancer:
              servers:
              - url: http://192.168.6.66:8080
        routers:
          TrueNAS:
            entrypoints:
            - http
            service: TrueNAS
            rule: >-
              Host(`truenas.montero`) ||
              Host(`truenas.montero.house.local`)

That's right. just stick it in the YAML. This keeps everything we need in one place.

Now we can access the UI:

$ curl -I http://truenas.montero/ui/
HTTP/1.1 200 OK
<snip>