Setup shipyrd-gem Docker image

[AliOsm]

What?

This PR sets up a Docker image for the shipyrd-gem gem.

Why?

To enable non-Ruby projects using Kamal as a deployment tool to benefit from Shipyrd without needing to install Ruby in their development environment.

How?

• Workflow: The PR adapts Kamal's docker-publish.yml workflow, only changing the repository name. Note that a new image will be generated on each release.

• Dockerfile: A simplified Kamal Dockerfile is created, removing Docker and SSH dependencies, and excluding an entry point.

• Scripts: 4 new scripts are added to the ./bin directory to run Shipyrd triggers. Users should add the following line to each Kamal hook supported by Shipyrd:

  docker run --rm -v "${PWD}:/workdir" --env-file <(env | grep -E '^(KAMAL_|SHIPYRD_)') 
  ghcr.io/shipyrd/shipyrd-gem:latest /shipyrd/bin/$(basename $0)

  • -v "${PWD}:/workdir": Binds the current directory to /workdir to access the latest commit message.
  • --env-file <(env | grep -E '^(KAMAL_|SHIPYRD_)'): Passes Kamal and Shipyrd environment variables to the shipyrd-gem container.
  • $(basename $0): Generalizes the command to be hook agnostic.

Testing

Tested on a Ruby on Rails project using a standard terminal and a DevContainer (within Docker). It is working fine. The shipyrd-gem image used for testing is available here.

Limitations

The shipyrd-gem container can't access the gh CLI to retrieve the GitHub username.

Next steps

Post-approval, the repository owner should create a repository secret named GH_TOKEN with a GitHub personal access token that has write:packages permission. No need for this step, I just knew about secrets.GITHUB_TOKEN being predefined in GitHub Actions.

Also, the main Shipyrd repository documentation should be updated.

Enhancements

• Consolidate the 4 scripts in ./bin into 1 script with an argument variable.
• Explore ways to reduce the Docker image size.

[AliOsm]

Closes #11

[AliOsm]

Hello @nickhammond, could you please take a look into the PR?

[nickhammond]

Hey @AliOsm - Thanks for opening this PR, I'll take a look at it this week!

[AliOsm]

Hello @nickhammond, any updates on this?

[nickhammond]

Hey @AliOsm - Nice work! Can you help update the readme with some of the details from your scripts section?

Thinking we can help users out with a function:

MacOS:

shipyrd() {
  docker run --platform linux/arm64 --rm -v "${PWD}:/workdir"  --env-file <(env | grep -E '^(KAMAL_|SHIPYRD_)') ghcr.io/shipyrd/shipyrd-gem:latest /shipyrd/bin/"$@"
}

Linux:
Just removing the platform

shipyrd() {
  docker run  --rm -v "${PWD}:/workdir"  --env-file <(env | grep -E '^(KAMAL_|SHIPYRD_)') ghcr.io/shipyrd/shipyrd-gem:latest /shipyrd/bin/"$@"
}

Then within .kamal/hooks/* or .kamal/hooks/pre-connect we just need:

#!/usr/bin/env zsh
shipyrd pre-connect

[AliOsm]

Hello @nickhammond, sure.

For MacOS vs Linux commands, docker can detect the required platform automatically and download the right image, so no need for different functions.

[nickhammond]

@AliOsm This is great, I'll get a release cut next week with this, thank you!