Release Helm Charts - GitHub Action
Overview
What it is
A reusable composite GitHub Action for publishing Helm charts to GitHub Pages. It detects changed charts, updates dependencies, runs helm lint, packages the chart, merges the repository index, and pushes the result to the Pages branch.
Why it exists
I built it to understand how composite GitHub Actions and Helm chart repositories work under the hood. I also wanted one release step I could reuse across my own projects instead of copying the same Bash workflow into each repo.
The project maps well to DevOps work: release automation, Git branch handling, Helm packaging, and CI jobs that update generated artifacts without causing loops.
Outcome
- Published on the GitHub Marketplace
- One reusable release step: detect changed charts, lint, package, publish to GitHub Pages
- Older chart versions stay installable after each release
- No-op runs make no commits, so release history stays clean
Implementation Highlights
The action runs one job: check out the source branch and the Pages branch side by side, diff the two trees to find changed charts, then run helm dependency update, helm lint, and helm package on each one before merging the result into index.yaml and pushing to the Pages branch.
Inputs cover the chart path, source branch, Pages branch, and commit metadata, and the repo ships Marketplace action metadata so other workflows can reuse it.
Key Challenges & Solutions
Challenge 1: Preserving Chart Version History
Problem: A Helm repository index lists every chart version users can install. If the action regenerated index.yaml from only the latest package, older chart versions would disappear from the repo metadata.
Solution: The action keeps the existing index.yaml from the Pages branch and passes it to helm repo index --merge. Helm adds new packages while preserving existing entries.
Older chart versions stay installable after new releases.