Generate the changelog for a release¶

Prerequisite¶

Prepare your Github Token
Install the Github python dependencies needed to generate the changelog.
```
pip install PyGithub
```

Generate release notes¶

Run the following command and fetch oneline git commits from the last release (v0.3.0) to current release (v0.4.0).
```
git log v0.3.0..v0.4.0 --oneline
```
You may need to run the following command first:
```
git fetch --tags
```

Copy the above commit history to scripts/changelog-generator.py and replace <your_github_token> with your Github token. Run the script to generate changelogs.

from github import Github
import re


class ChangelogGenerator:
    def __init__(self, github_repo):
        # Replace <your_github_token> with your Github Token
        self._github = Github('<your_github_token>')
        self._github_repo = self._github.get_repo(github_repo)

    def generate(self, pr_id):
        pr = self._github_repo.get_pull(pr_id)

        return "{title} ([#{pr_id}]({pr_link}), @{user})".format(
            title=pr.title,
            pr_id=pr_id,
            pr_link=pr.html_url,
            user=pr.user.login
        )


# generated by `git log <oldTag>..<newTag> --oneline`
payload = '''
7374e2c [RayService] Skip update events without change (#811) (#825)
7f83353 Switch to 0.4.0 and eliminate Chart app versions. (#810)
86b0af2 Remove ingress.enabled from KubeRay operator chart (#812) (#816)
c1cbaed Update chart versions for 0.4.0-rc.0 (#804)
84a70f1 Update image tags. (#784)
d760b9c [helm] Add memory limits and resource documentation. (#789) (#798)
16905df [Feature] Improve the observability of integration tests (#775) (#796)
83aab82 [CI] Pin go version in CRD consistency check (#794) (#797)
....
'''

g = ChangelogGenerator("ray-project/kuberay")
for pr_match in re.finditer(r"#(\d+)", payload):
    pr_id = int(pr_match.group(1))
    print("* {}".format(g.generate(pr_id)))

To create the release notes, save the output of the script. Modify the script's output as follows.
- Remove extraneous data, such as commits with tag information or links to other PRs, e.g.
```
- c1cbaed (tag: v0.4.0-rc.0) Update chart versions for 0.4.0-rc.0 (#804) -> c1cbaed Update chart versions for 0.4.0-rc.0 (#804)
- 86b0af2 Remove ingress.enabled from KubeRay operator chart (#812) (#816) -> 86b0af2 Remove ingress.enabled from KubeRay operator chart (#816)
```
- Group commits by category e.g. KubeRay Operator, Documentation, etc. (The choice of categories is at the release manager's discretion.)
- Add a section summarizing important changes.
- Add a section listing individuals who contributed to the release.
Cut the release from tags and add the release notes from the last step. For an example, see the v0.3.0 release notes.
Send a PR to update CHANGELOG.md. The changelog should be updated by prepending the new release notes.