Devcontainer GUI Apps

Properties1
tagstools, dev, containers, vscode, vnc

2 min read

Run GUI apps inside a devcontainer via a lightweight Fluxbox desktop, reachable through noVNC in a browser or any VNC client. The desktop-lite feature handles this without a custom Dockerfile.

{
  "features": {
    "ghcr.io/devcontainers/features/desktop-lite:1": {
      "webPort": "6080",
      "vncPort": "5901"
    }
  },
  "containerEnv": {
    "VNC_RESOLUTION": "1920x1080x16"
  },
  "forwardPorts": [5901, 6080],
  "portsAttributes": {
    "6080": { "label": "Desktop (noVNC - browser)" }
  }
}

Resolution

The feature defaults to 1440x768x16, which is too short and hides the Fluxbox topbar behind fullscreen app windows. Override it with VNC_RESOLUTION in containerEnv.

Access

  • Browser: forward webPort (6080) and open it — noVNC serves a full VNC client as a web page, no extra software needed.
  • Native VNC client: forward vncPort (5901) and point the client at localhost:5901.

With devpod, both ports in forwardPorts reach localhost automatically — no manual tunnel required. Outside devpod (plain SSH-hosted container), forward them yourself as in the Cheatsheet below.

Password

The VNC password defaults to "vscode" if VNC_PASSWORD isn’t set in containerEnv. That’s only safe when the desktop is never exposed directly — e.g. reachable solely through an SSH tunnel you open yourself, on a machine only you have access to. Set VNC_PASSWORD explicitly for anything more exposed.

Cheatsheet

ssh -L 6080:localhost:6080 <user>@<remote-host>  # tunnel noVNC to the browser
ssh -L 5901:localhost:5901 <user>@<remote-host>  # tunnel to a native VNC client

Graph View

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