Colima-ui appimage fails without docker daemon detection

[CrazyAce25]

When launching the appimage from the cli, it shows, "Gtk-Message: 10:58:42.132: Failed to load module "xapp-gtk3-module"
[DockerState] Docker daemon not reachable — starting with empty state." Is this looking to find Docker daemon on the host itself, or Docker daemon running within a VM created by Colima?

[architectureman]

Hi @CrazyAce25, thank you for reaching out!

To answer your questions:

1. Where is it looking for the daemon?
   ColimaUI is designed to first look for the Docker daemon running within the VM created by Colima. It does this by checking the sockets exposed on your host machine (specifically looking for ~/.colima/default/docker.sock or your specific Colima profile). If it cannot find a running Colima instance, it falls back to looking for a standard host Docker daemon (via the DOCKER_HOST environment variable or /var/run/docker.sock).

2. Is there a hard requirement for the Docker daemon?
   Yes, currently there is. Under the hood, ColimaUI uses a Rust client called Bollard to communicate with the container runtime via the standard Docker REST API.

   • If you start Colima with containerd (nerdctl), it does not expose a Docker-compatible HTTP API, so the UI cannot fetch containers or images.
   • If you use podman, it does have a Docker-compatible API, but the UI is currently strictly looking for the docker.sock file path.

So for now, the UI strictly requires Colima to be running with the default docker runtime to function correctly. Supporting containerd/nerdctl would require a different backend client, which is something we might consider for the future ecosystem roadmap.

Hope this clarifies things!