This repo provides a starting point and example for creating your own custom dev container Features, hosted for free on GitHub Container Registry. The example in this repository follows the dev container Feature distribution specification.
To provide feedback to the specification, please leave a comment on spec issue #70. For more broad feedback regarding dev container Features, please see spec issue #61.
This repository contains a collection of two Features - hello
and color
. These Features serve as simple feature implementations. Each sub-section below shows a sample devcontainer.json
alongside example usage of the Feature.
TBD: short summary of spin
{
"image": "mcr.microsoft.com/devcontainers/base:ubuntu",
"features": {
"ghcr.io/ThorstenHans/devcontainer-features/spin:1": {
"version": "latest"
}
}
}
$ spin --version
spin 1.4.1 (e0bd911 2023-07-12)
Similar to the devcontainers/features
repo, this repository has a src
folder. Each Feature has its own sub-folder, containing at least a devcontainer-feature.json
and an entrypoint script install.sh
.
├── src
│ ├── fermyon-spin
│ │ ├── devcontainer-feature.json
│ │ └── install.sh
...
An implementing tool will composite the documented dev container properties from the feature's devcontainer-feature.json
file, and execute in the install.sh
entrypoint script in the container during build time. Implementing tools are also free to process attributes under the customizations
property as desired.
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.
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.
Allow GitHub Actions to create and approve pull requests should be enabled in the repository's Settings > Actions > General > Workflow permissions
for auto generation of src/<feature>/README.md
per Feature (which merges any existing src/<feature>/NOTES.md
).
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.
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
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.
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"
}
}
}
}
}
}