How do you run a private Docker Registry with Dokploy?

[MoinJulian]

I tried running registry:2/3 with joxit/docker-registry-ui on Dokploy. The registry works internally and authentication works via curl, but docker login through the Dokploy-managed domain returns HTTP 400.

Is there a recommended way to run a private Docker Registry with Dokploy? Should I use Harbor or is there a built-in approach?
And if I use Harbor is there anyway to to it via the Dokploy UI or do I have to ssh onto the server?

Thanks for any answers in advance

[dosubot[bot]]

Hi @MoinJulian! I'm Dosu and I'm helping the Dokploy team.

The HTTP 400 you're seeing with docker login is very likely caused by a missing environment variable. The critical setting for running Docker Registry behind Dokploy's Traefik reverse proxy is REGISTRY_HTTP_RELATIVEURLS=true [1]. Without it, Docker's push/pull/login protocol breaks because Traefik rewrites URLs in a way the registry doesn't expect. A community member confirmed this fixed their "unknown blob" errors when running a registry behind Traefik [2].

Dokploy actually has an official Docker Registry template in the templates repository that's already configured correctly [3]. It uses registry:3 with htpasswd auth and includes that critical relative URLs setting. You can deploy it from the Dokploy UI via the templates feature. Here's the key compose configuration it uses:

services:
  registry:
    image: registry:3
    environment:
      - USERNAME=${USERNAME}
      - PASSWORD=${PASSWORD}
      - REGISTRY_AUTH=htpasswd
      - REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm
      - REGISTRY_AUTH_HTPASSWD_PATH=/auth/registry.password
      - REGISTRY_HTTP_RELATIVEURLS=true  # Critical for Traefik
    entrypoint: ["sh", "/entrypoint.sh"]
    volumes:
      - registry-data:/var/lib/registry
    expose:
      - 5000

[1]

The domain should be mapped to port 5000 of the registry service [3].

Regarding your other questions:

• Harbor: There is no Harbor template or built-in Harbor support in Dokploy. You'd have to set it up manually via SSH, and it's significantly more complex than a simple registry.
• Built-in approach: Dokploy has built-in registry management (for storing credentials and integrating with deploy flows), but for hosting a registry, the official template above is the recommended path [4].
• joxit/docker-registry-ui: Not part of the official template, but you could add it as an additional service in the compose file pointing at your registry.

If you're still getting HTTP 400 after adding REGISTRY_HTTP_RELATIVEURLS=true, double-check that your Dokploy domain is mapped to port 5000 and review Traefik logs for routing clues.

To reply, just mention @dosu.

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