DDEV devcontainer feature

Distributing Features

Versioning

Features are individually versioned by the version attribute in a Feature's devcontainer-feature.json. Features are versioned according to the semver specification. More details can be found in the dev container Feature specification.

Publishing

NOTE: The Distribution spec can be found here.

While any registry implementing the OCI Distribution spec can be used, this template will leverage GHCR (GitHub Container Registry) as the backing registry.

Features are meant to be easily sharable units of dev container configuration and installation code.

This repo contains a GitHub Action workflow that will publish each feature to GHCR. By default, each Feature will be prefixed with the <owner/<repo> namespace. For example, the two Features in this repository can be referenced in a devcontainer.json with:

ghcr.io/devcontainers/feature-starter/color:1
ghcr.io/devcontainers/feature-starter/hello:1

The provided GitHub Action will also publish a third "metadata" package with just the namespace, eg: ghcr.io/devcontainers/feature-starter. This contains information useful for tools aiding in Feature discovery.

'devcontainers/feature-starter' is known as the feature collection namespace.

Marking Feature Public

Note that by default, GHCR packages are marked as private. To stay within the free tier, Features need to be marked as public.

This can be done by navigating to the Feature's "package settings" page in GHCR, and setting the visibility to 'public`. The URL may look something like:

https://github.com/users/<owner>/packages/container/<repo>%2F<featureName>/settings

Adding Features to the Index

If you'd like your Features to appear in our public index so that other community members can find them, you can do the following:

• Go to github.com/devcontainers/devcontainers.github.io
  • This is the GitHub repo backing the containers.dev spec site
• Open a PR to modify the collection-index.yml file

This index is from where supporting tools like VS Code Dev Containers and GitHub Codespaces surface Features for their dev container creation UI.

Using private Features in Codespaces

For any Features hosted in GHCR that are kept private, the GITHUB_TOKEN access token in your environment will need to have package:read and contents:read for the associated repository.

Many implementing tools use a broadly scoped access token and will work automatically. GitHub Codespaces uses repo-scoped tokens, and therefore you'll need to add the permissions in devcontainer.json

An example devcontainer.json can be found below.

{
    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
    "features": {
     "ghcr.io/my-org/private-features/hello:1": {
            "greeting": "Hello"
        }
    },
    "customizations": {
        "codespaces": {
            "repositories": {
                "my-org/private-features": {
                    "permissions": {
                        "packages": "read",
                        "contents": "read"
                    }
                }
            }
        }
    }
}