Homework — Chart Packaging & Registries

Apply what you learned about packaging, repositories, OCI registries, and CI/CD pipelines.

Task 1 — GitHub Pages Chart Repository

Set up a chart repository hosted on GitHub Pages. This simulates a real open-source chart distribution workflow.

Create a new GitHub repository (or use an existing one) and enable GitHub Pages on the docs/ folder of the main branch.
Create a Helm chart called myservice with version: 1.0.0 and appVersion: "2.0.0".
Write a .helmignore that excludes .git, *.md, tests/, ci/, .env, and editor swap files.
Package the chart into the docs/ directory.
Generate index.yaml with your GitHub Pages URL as the base URL.

Commit, push, and verify the repo works:

helm repo add mypages https://<username>.github.io/<repo>
helm repo update
helm search repo mypages/myservice

Bump the chart to version: 1.1.0, re-package, regenerate the index (use --merge to preserve existing entries), commit, and push.
Verify both versions are discoverable with helm search repo mypages/myservice --versions.

Self-Check

helm repo add succeeds without errors.
helm search repo --versions shows both 1.0.0 and 1.1.0.
The index.yaml has correct urls pointing to the GitHub Pages domain.
The .helmignore keeps the archive lean (no .md, no tests/).

Task 2 — OCI Multi-Version Release Pipeline

Build a shell script that automates the full lint-package-push pipeline for an OCI registry.

Start a local OCI registry: docker run -d -p 5000:5000 --name hw-registry registry:2

Create a shell script called release.sh that accepts a chart directory and a version as arguments and performs:

#!/usr/bin/env bash
set -euo pipefail

CHART_DIR="$1"
VERSION="$2"
REGISTRY="oci://localhost:5000/charts"

# Step 1: Lint
helm lint "$CHART_DIR" --strict

# Step 2: Package with version override
helm package "$CHART_DIR" --version "$VERSION" -d ./build/

# Step 3: Push to OCI registry
ARCHIVE="./build/$(basename "$CHART_DIR")-${VERSION}.tgz"
helm push "$ARCHIVE" "$REGISTRY"

echo "Released $(basename "$CHART_DIR") v${VERSION}"

Run the script three times to release versions 1.0.0, 1.1.0, and 2.0.0-rc1 of your chart.

Verify all three tags exist in the registry:

curl -s http://localhost:5000/v2/charts/<name>/tags/list

Pull each version and confirm the Chart.yaml inside has the correct version.

Self-Check

release.sh exits on any lint or push failure (set -euo pipefail).
The registry API returns all three tags: 1.0.0, 1.1.0, 2.0.0-rc1.
helm show chart oci://localhost:5000/charts/<name> --version 2.0.0-rc1 shows the correct metadata.
The pre-release version (2.0.0-rc1) is a valid SemVer string.

Task 3 — GitHub Actions CI/CD Workflow (Stretch)

Write a GitHub Actions workflow that automates chart releases on tag pushes.

Create .github/workflows/helm-release.yaml in a GitHub repository.
Trigger on pushes of tags matching v* (e.g., v1.2.0).
The workflow should:
- Check out the repository.
- Install Helm using azure/setup-helm@v4.
- Run helm lint --strict.
- Run helm template to validate rendered output.
- Package the chart with the version derived from the tag (${GITHUB_REF_NAME#v}).
- Authenticate to GitHub Container Registry using GITHUB_TOKEN.
- Push to oci://ghcr.io/${{ github.repository_owner }}/charts.
Test by creating and pushing a tag: git tag v1.0.0 && git push origin v1.0.0.
Verify the chart appears in your GitHub Packages page.

Self-Check

The workflow runs without errors on tag push.
The lint step would catch a broken chart (test by intentionally breaking a template).
The chart is visible at ghcr.io/<owner>/charts/<name>.
helm pull oci://ghcr.io/<owner>/charts/<name> --version 1.0.0 works from a different machine (if the package is public).

Grading Rubric

Criterion	Points	Description
Task 1 — GitHub Pages repo works	35	Both chart versions are discoverable via `helm search repo`; `index.yaml` is correct; `.helmignore` is present and effective.
Task 2 — OCI pipeline script	40	Script lints, packages, and pushes; all three versions appear in registry; `set -euo pipefail` ensures failure stops the pipeline; pulled charts have correct metadata.
Task 3 — GitHub Actions workflow	25	Workflow file is syntactically valid; includes lint, template, package, and push stages; uses tag-derived versioning; authenticates correctly to GHCR.
Total	100

Note: Task 3 is a stretch goal. If you do not have a GitHub account or prefer not to push to a public registry, you can write the workflow file locally and validate it with actionlint or the online checker without actually running it.