Add docs for releasing arena (#1201)

Signed-off-by: Yi Chen <[email protected]>

README.md

@@ -1,6 +1,6 @@
 # Arena
 
-[![Integration Test](https://github.com/kubeflow/arena/actions/workflows/integration.yaml/badge.svg)](https://github.com/kubeflow/arena/actions/workflows/integration.yaml)[![Go Report Card](https://goreportcard.com/badge/github.com/kubeflow/arena)](https://goreportcard.com/report/github.com/kubeflow/arena)
+[![GitHub release](https://img.shields.io/github/v/release/kubeflow/arena)](https://github.com/kubeflow/arena/releases) [![Integration Test](https://github.com/kubeflow/arena/actions/workflows/integration.yaml/badge.svg)](https://github.com/kubeflow/arena/actions/workflows/integration.yaml) [![Go Report Card](https://goreportcard.com/badge/github.com/kubeflow/arena)](https://goreportcard.com/report/github.com/kubeflow/arena)
 
 View the [Arena documentation](https://arena-docs.readthedocs.io/en/latest).
 

docs/release.md

@@ -0,0 +1,87 @@
+# Releasing Arena
+
+## Prerequisites
+
+- [Write](https://docs.github.com/organizations/managing-access-to-your-organizations-repositories/repository-permission-levels-for-an-organization#permission-levels-for-repositories-owned-by-an-organization) permission for the [kubeflow/arena](https://github.com/kubeflow/arena) repository.
+
+- Create a [GitHub Token](https://docs.github.com/github/authenticating-to-github/keeping-your-account-and-data-secure/creating-a-personal-access-token).
+
+- Install `PyGithub`:
+
+    ```bash
+    pip install PyGithub==2.3.0
+    ```
+
+## Versioning Policy
+
+Arena version format follows [Semantic Versioning](https://semver.org/). Arena versions are in the format of `vX.Y.Z`, where `X` is the major version, `Y` is the minor version, and `Z` is the patch version. The patch version contains only bug fixes.
+
+## Release Process
+
+### Update Versions
+
+1. Modify `VERSION` file in the root directory of the project:
+
+    - For the RC tag as follows:
+
+    ```bash
+    vX.Y.Z-rc.N
+    ```
+
+    - For the official release tag as follows:
+
+    ```bash
+    vX.Y.Z
+    ```
+
+2. Modify `version` and `appVersion` in `Chart.yaml`:
+
+    ```bash
+    # Get version and remove the leading 'v'
+    VERSION=$(cat VERSION | sed "s/^v//")
+
+    # Change the version and appVersion in Chart.yaml
+    # On Linux
+    sed -i "s/^version.*/version: ${VERSION}/" arena-artifacts/Chart.yaml
+    sed -i "s/^appVersion.*/appVersion: ${VERSION}/" arena-artifacts/Chart.yaml
+
+    # On MacOS
+    sed -i '' "s/^version.*/version: ${VERSION}/" arena-artifacts/Chart.yaml
+    sed -i '' "s/^appVersion.*/appVersion: ${VERSION}/" arena-artifacts/Chart.yaml
+    ```
+
+3. Commit and push the changes to your own branch:
+
+    ```bash
+    git add VERSION
+    git add arena-artifacts/Chart.yaml
+    git commit -s -m "Release v${VERSION}"
+    git push --set-upstream origin $(git rev-parse --abbrev-ref HEAD)
+    ```
+
+4. Open a new PR to the master branch.
+
+### Publish release
+
+After `VERSION` file is modified and pushed to the master branch, a release workflow will be triggered to create a new draft release with the arena installer packaged as artifacts. After modifying the release notes, then publish the release.
+
+## Update Changelog
+
+1. Update the `CHANGELOG.md` file by running:
+
+    ```bash
+    # Use your GitHub token.
+    GH_TOKEN=<github-token>
+    # The previous release version, e.g. v1.7.1
+    PREVIOUS_RELEASE=vX.Y.Z
+    # The current release version, e.g. v1.8.0
+    CURRENT_RELEASE=vX.Y.Z
+
+    python hack/generate-changelog.py \
+        --token=${GH_TOKEN} \
+        --range=${PREVIOUS_RELEASE}..<CURRENT_RELEASE>
+    ```
+
+2. Group PRs in the `CHANGELOG.md` file into **Features**, **Bug Fixes** and **Misc**, etc.
+
+3. Finally, open a new PR to the master branch with the updated Changelog.