decolint on GitHub

no-bind-mount

disallow “bind” type entries in “mounts”, which GitHub Codespaces silently ignores except for the Docker socket

Category
correctness
Applies to
devcontainer
Platforms
codespaces

Why

A codespace runs on a machine in the cloud, where the host path a bind mount points at does not exist, so Codespaces documents that it ignores “bind” mounts apart from the Docker socket. The mount is dropped without an error and the container starts missing the data it expects. Volume mounts are honored, so use “type=volume” for anything that only has to persist across rebuilds.

Bad

{
  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
  "mounts": [
    {
      "source": "${localWorkspaceFolder}/.cache",
      "target": "/home/vscode/.cache",
      "type": "bind"
    }
  ]
}

Good

{
  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
  "mounts": [
    {
      "source": "devcontainer-cache",
      "target": "/home/vscode/.cache",
      "type": "volume"
    }
  ]
}

References