# Contributing to Dagger

## GitHub Workflow

The recommended workflow is to clone the repository from `dagger/dagger` and
open pull requests from your own fork.

### 1) Cloning the repository

```sh
git clone https://github.com/dagger/dagger.git
```

**NOTE**: If you cloned your fork, either switch back to `dagger/dagger` using
`git remote` or start over.

### 2) Forking

- Click on the _Fork_ button on GitHub
- Add your fork as a remote

```sh
git remote add fork git@github.com:MYFORK/dagger.git
```

### 3) Creating a Pull Request

```sh
# create a branch
git checkout -b mybranch

# make changes to your branch, use `git commit -s`, ...
# ...

# push the branch to your own fork
git push -u fork mybranch

# create a pull request from https://github.com/dagger/dagger
```

### 4) Rebasing

```sh
git checkout main
git pull  # <-- this will pull from `dagger/dagger`
git checkout mybranch
git rebase main  # <-- this will rebase `dagger/dagger` into your `FORK/dagger`
git push -f -u fork mybranch  # <-- update the pull request
```

## Commits

### DCO

Contributions to this project must be accompanied by a Developer Certificate of
Origin (DCO).

All commit messages must contain the Signed-off-by line with an email address that matches the commit author. When commiting, use the `--signoff` flag:

```sh
git commit -s
```

The Signed-off-by line must match the **author's real name**, otherwise the PR will be rejected.

### Commit Messages

[How to Write a Git Commit Message](https://chris.beams.io/posts/git-commit/)

Guidelines:

- Group Commits: Each commit should represent a meaningful change (e.g. implement
  feature X, fix bug Y, ...).
- For instance, a PR should not look like _1) Add Feature X 2) Fix Typo 3) Changes to features X 5) Bugfix for feature X 6) Fix Linter 7) ..._<br>
  Instead, these commits should be squashed together into a single "Add Feature" commit.
- Each commit should work on its own: it must compile, pass the linter and so on.
- This makes life much easier when using `git log`, `git blame`, `git bisect`, etc.
- For instance, when doing a `git blame` on a file to figure out why a change
  was introduced, it's pretty meaningless to see a _Fix linter_ commit message.
  "Add Feature X" is much more meaningful.
- Use `git rebase -i main` to group commits together and rewrite their commit message
- To add changes to the previous commit, use `git commit --amend -s`. This will
  change the last commit (amend) instead of creating a new commit.
- Format: Use the imperative mood in the subject line: "If applied, this commit
  will _your subject line here_"

## Docs

### Use relative links to markdown files

Link to markdown files (`[link](../foo.md)`) instead of relative URLs
(`[link](/foo)`).

The docs compiler will replace file links with relative URLs automatically.

This is to avoid broken links. If a file gets renamed, the compiler will
catch broken links and throw an error. Relative URLs get broken unnoticed.

## FAQ

### How to run the markdown linter locally

First install `markdownlint-cli`:

- On Mac OS: `brew install markdownlint-cli`
- On other systems, with yarn installed: `yarn global add markdownlint-cli`

Then from the repository root:

```console
markdownlint -c .markdownlint.yaml docs/**/*.md
```
