Docker Image will not work behind Proxy

[SvartrShell]

Having an issue getting this to work behind my reverse proxy - no matter what combo of ETESYNC_SERVER_HOSTS i put i get errors

  etesync-dav:
    container_name: etesync-dav
    image: etesync/etesync-dav:latest
    restart: always
    environment:
      ETESYNC_LISTEN_ADDRESS: 0.0.0.0
      ETESYNC_SERVER_HOSTS: 'host.domain.com,DOCKER_IP_ADD'
    ports:
      - "37358:37358"
    volumes:
      - "etesync-dav:/data"

gives error
[2025-04-09 09:57:12 +0000] [1] [CRITICAL] Invalid configuration: Invalid list_of_ip_address value for option 'hosts' in section 'server' in arguments: 'host.domain.com,DOCKER_IP_ADD'

I have tried all combos, adding port 443 to the host name, removing it entirely - nothing works - it used to - but i recently updated and it stopped working

[SvartrShell]

ok, well this is a pretty weird way of handling proxies - i have sort of got it working - i had to set the ETESYNC_LISTEN_ADDRESS to host.domain.com and then uncomment out the ETESYNC_SERVER_HOSTS - it now works through my reverse proxy but i cant access it via the docker host IP and port as i get

Bad Request
Host 'HOST.IP:37358' is not trusted.

Even if i add the host ip and port to ETESYNC_SERVER_HOSTS it fails - AND i cant get to it via the proxy url.

Why cant this just have a trusted proxies var and allow any connections to it from that - im not exposing this mgmt interface to the public internet but i use SSL/HTTPS offloading even for internal traffic to prevent data leaks and this is a really annoying issue

[tasn]

Yeah, it's indeed annoying. Unfortunately we rely on a 3rd party server (radicale) and that's how it's configured there. We could probably make it better, but haven't found a way.

This is the relevant section in the README: https://github.com/etesync/etesync-dav/?tab=readme-ov-file#common-environment-variables
Have you tried just setting hostname,ip to listen addresses and hostname:37358,ip:37358 to both?

Btw, it most definitely works behind a reverse proxy (you're not the only one that's doing it), but hard to comment about your specific setup and what's going on there.

[SvartrShell]

Yeah, it's indeed annoying. Unfortunately we rely on a 3rd party server (radicale) and that's how it's configured there. We could probably make it better, but haven't found a way.

This is the relevant section in the README: https://github.com/etesync/etesync-dav/?tab=readme-ov-file#common-environment-variables Have you tried just setting hostname,ip to listen addresses and hostname:37358,ip:37358 to both?

Btw, it most definitely works behind a reverse proxy (you're not the only one that's doing it), but hard to comment about your specific setup and what's going on there.

Thanks for responding, yes I tried that method - essentially though, if i put any type of hostname or non-ip string in the ETESYNC_SERVER_HOSTS, it gives me an error that invalid configuration error everytime. After an hour or so of testing - the only way i could get this somewhat working was with this

  etesync-dav:
    container_name: etesync-dav
    image: etesync/etesync-dav:latest
    restart: always
    environment:
      ETESYNC_LISTEN_ADDRESS: fqdn.domain.com
      # ETESYNC_SERVER_HOSTS: 0.0.0.0:37358
    ports:
      - "37358:37358"
    volumes:
      - "etesync-dav:/data"
      -

this results in me being able to reach the url through my proxy, but breaks any sort of IP resolution due to the not trusted error. I will paste a few examples of what I have tried unsuccessfully below - perhaps someone can highlight a glaring issue im missing

  etesync-dav:
    container_name: etesync-dav
    image: etesync/etesync-dav:latest
    restart: always
    environment:
      ETESYNC_LISTEN_ADDRESS: fqdn.domain.com,10.20.20.105
      ETESYNC_SERVER_HOSTS: 0.0.0.0:37358,0.0.0.0:443
    ports:
      - "37358:37358"
    volumes:
      - "etesync-dav:/data"

  etesync-dav:
    container_name: etesync-dav
    image: etesync/etesync-dav:latest
    restart: always
    environment:
      ETESYNC_LISTEN_ADDRESS: fqdn.domain.com
      ETESYNC_SERVER_HOSTS: 0.0.0.0:37358,0.0.0.0:443
    ports:
      - "37358:37358"
    volumes:
      - "etesync-dav:/data"

  etesync-dav:
    container_name: etesync-dav
    image: etesync/etesync-dav:latest
    restart: always
    environment:
      ETESYNC_LISTEN_ADDRESS: DOCKER.IP.ADD
      # ETESYNC_SERVER_HOSTS: 0.0.0.0:37358,10.20.20.105:37358
    ports:
      - "37358:37358"
    volumes:
      - "etesync-dav:/data"

  etesync-dav:
    container_name: etesync-dav
    image: etesync/etesync-dav:latest
    restart: always
    environment:
      ETESYNC_LISTEN_ADDRESS: docker.ip.add
      ETESYNC_SERVER_HOSTS: fqdm.domain.com:443
    ports:
      - "37358:37358"
    volumes:
      - "etesync-dav:/data"

The list goes on, as far as im aware, and having read the below, hostname should be accepted in ETESYNC_SERVER_HOSTS however in every one of my tests, whenever there was any form of FQDN in that variable, it would fail to start, giving an error of some kind

Common environment variables
ETESYNC_LISTEN_ADDRESS: a hostname or IP address to listen on. Requests to a different host/ip will be block for the admin UI. Uses as the default value for the next setting.
ETESYNC_SERVER_HOSTS: defaults to {ETESYNC_LISTEN_ADDRESS}:37358. Otherwise, a list of IP masks, hostnames, and ports for the server to listen on. E.g. 0.0.0.0:37358,[::]:37358 for listening on all ipv4 and ipv6 addresses and port 37358, or localhost:37358 to only allow requests from localhost.