SOLVED: Traefik Reverse proxy works with https but shows "Select Server" with http

[davedv]

I have set up Jellyfin behind a Traefik reverse proxy, and I am trying to set up both https (from an external domain, jellyfin.mydomain.com) and http (with a jellyfin.local DNS) endpoints, both relaying to Jellyfin's http port.

Things work fine with the external https endpoint, but when trying to use the http endpoint through my local URL, I get a Jellyfin screen asking me to "Select a server", and clicking on the server, leads to an error message "We're unable to connect to the selected server right now"We

Switching the jellyfin.local config to an https endpoint and TLS works fine (but since I cannot have a properly-signed certificate, it's not ideal).

I have tried turning on/off the different middleware options, and modifying values in the network.xml file, but nothing seems to work.

Any idea what might be causing this?

Relevant parts of Jellyfin's docker compose:

Code:

[...]
        labels:
            - "traefik.enable=true"
            # Remote
            - "traefik.http.routers.jellyfin_secure.rule=Host(`jellyfin.mydomain.com`)"
            - "traefik.http.routers.jellyfin_secure.entrypoints=https"
            - "traefik.http.routers.jellyfin_secure.tls=true"
            - "traefik.http.routers.jellyfin_secure.tls.certresolver=myresolver"
            - "traefik.http.routers.jellyfin_secure.service=jellyfin"
            - 'traefik.http.routers.jellyfin_secure.middlewares=jellyfin-mw'
            # Local:
            - "traefik.http.routers.jellyfin.rule=Host(`jellyfin.local`)"
            - "traefik.http.routers.jellyfin.entrypoints=http"
            - "traefik.http.routers.jellyfin.service=jellyfin"
            - 'traefik.http.routers.jellyfin.middlewares=jellyfin-mw'
            # service
            - "traefik.http.services.jellyfin.loadbalancer.server.port=8096"
            - 'traefik.http.services.jellyfin.loadBalancer.passHostHeader=true'
            - 'traefik.http.middlewares.jellyfin-mw.headers.customResponseHeaders.X-Robots-Tag=noindex,nofollow,nosnippet,noarchive,notranslate,noimageindex'
            - 'traefik.http.middlewares.jellyfin-mw.headers.STSSeconds=315360000'
            - 'traefik.http.middlewares.jellyfin-mw.headers.STSIncludeSubdomains=true'
            - 'traefik.http.middlewares.jellyfin-mw.headers.STSPreload=true'
            - 'traefik.http.middlewares.jellyfin-mw.headers.forceSTSHeader=true'
            - 'traefik.http.middlewares.jellyfin-mw.headers.frameDeny=true'
            - 'traefik.http.middlewares.jellyfin-mw.headers.contentTypeNosniff=true'
            - 'traefik.http.middlewares.jellyfin-mw.headers.customresponseheaders.X-XSS-PROTECTION=1'
        networks:
            - traefik_net

networks:
    traefik_net:
        external: true  # Reuse the network from Traefik

Network.xml is the default one.

[davedv]

Additional info:

disabling STS-specific headers in the middleware doesn't help:
<code>
# - 'traefik.http.middlewares.jellyfin-mw.headers.STSSeconds=315360000'
# - 'traefik.http.middlewares.jellyfin-mw.headers.STSIncludeSubdomains=true'
# - 'traefik.http.middlewares.jellyfin-mw.headers.STSPreload=true'
# - 'traefik.http.middlewares.jellyfin-mw.headers.forceSTSHeader=true'
</code>

Relevant parts from Jellyfin's log:
<code>
[...]
jellyfin | [custom-init] No custom files found, skipping...
jellyfin | [09:24:27] [INF] [1] Main: Jellyfin version: 10.10.6
jellyfin | [09:24:27] [INF] [1] Main: Environment Variables: ["[JELLYFIN_LOG_DIR, /config/log]", "[JELLYFIN_CONFIG_DIR, /config]", "[JELLYFIN_CACHE_DIR, /config/cache]", "[JELLYFIN_DATA_DIR, /config/data]", "[JELLYFIN_WEB_DIR, /usr/share/jellyfin/web]"]
jellyfin | [09:24:27] [INF] [1] Main: Arguments: ["/usr/lib/jellyfin/bin/jellyfin.dll", "--ffmpeg=/usr/lib/jellyfin-ffmpeg/ffmpeg"]
jellyfin | [09:24:27] [INF] [1] Main: Operating system: Ubuntu 24.04.2 LTS
jellyfin | [09:24:27] [INF] [1] Main: Architecture: Arm64
jellyfin | [09:24:27] [INF] [1] Main: 64-Bit Process: True
jellyfin | [09:24:27] [INF] [1] Main: User Interactive: True
jellyfin | [09:24:27] [INF] [1] Main: Processor count: 4
jellyfin | [09:24:27] [INF] [1] Main: Program data path: /config/data
jellyfin | [09:24:27] [INF] [1] Main: Log directory path: /config/log
jellyfin | [09:24:27] [INF] [1] Main: Config directory path: /config
jellyfin | [09:24:27] [INF] [1] Main: Cache path: /config/cache
jellyfin | [09:24:27] [INF] [1] Main: Temp directory path: /tmp/jellyfin
jellyfin | [09:24:27] [INF] [1] Main: Web resources path: /usr/share/jellyfin/web
jellyfin | [09:24:27] [INF] [1] Main: Application directory: /usr/lib/jellyfin/bin/
jellyfin | [09:24:27] [INF] [1] Emby.Server.Implementations.AppBase.BaseConfigurationManager: Setting cache path: /config/cache
jellyfin | [09:24:28] [INF] [1] Emby.Server.Implementations.ApplicationHost: Loading assemblies
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Defined LAN subnets: ["127.0.0.1/8", "10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"]
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Defined LAN exclusions: []
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Used LAN subnets: ["127.0.0.1/8", "10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"]
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Filtered interface addresses: ["127.0.0.1", "172.18.0.3"]
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Bind Addresses ["0.0.0.0"]
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Remote IP filter is Allowlist
jellyfin | [09:24:28] [INF] [1] Jellyfin.Networking.Manager.NetworkManager: Filtered subnets: []
</code>

[davedv]

Seem to have found my solution: posting here for anyone who might land on this post:

It turns out the main issue was with localstorage: deleting it after restarting the server, allowed me to log back in.
I was emptying the cache, but did not realise that would still preserve localstorage (duh).

Console logs showed the hint: "http request succeeded, but found a different server Id than what was expected"
Worth noting that restarting the server (after changing misc middleware settings) seems to require emptying localstorage again (guess that resets the server ID?)

In the end, that seemed to be the only issue (works with whatever middleware settings). IMHO this behaviour is slightly buggy and should display something more informative when server IDs mysteriously change…