Operator helm releases should push index to GH pages (#1481)

Summary: We want to start using Github to host our Helm charts. As a
part of that process, we should update the `index.yaml` with the new
helm chart entry. This PR updates the helm build release script to
generate the new index file, and also updates the Github workflow to
push it to the gh-pages branch.

Relevant Issues: N/A

Type of change: /kind cleanup

Test Plan: Build an rc

---------

Signed-off-by: Michelle Nguyen <michellenguyen@pixielabs.ai>

Author: aimichelle

.github/workflows/operator_release.yaml

@@ -43,10 +43,12 @@ jobs:
         COSIGN_PASSWORD: ${{secrets.COSIGN_PASSWORD}}
         COSIGN_PRIVATE_KEY: ${{secrets.COSIGN_PRIVATE_KEY}}
         GOOGLE_APPLICATION_CREDENTIALS: ${{ steps.gcloud-creds.outputs.gcloud-creds }}
+        GH_REPO: ${{ github.repository }}
       shell: bash
       run: |
         export TAG_NAME="${REF#*/tags/}"
         export ARTIFACTS_DIR="$(pwd)/artifacts"
+        export INDEX_FILE="$(pwd)/index.yaml"
         mkdir -p "${ARTIFACTS_DIR}"
         ./ci/save_version_info.sh
         ./ci/operator_build_release.sh
@@ -65,6 +67,10 @@ jobs:
       with:
         name: operator-artifacts
         path: artifacts/
+    - uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce  # v3.1.2
+      with:
+        name: index-artifacts
+        path: index.yaml
   create-github-release:
     if: ${{ !contains(github.event.ref, '-') }}
     name: Create Release on Github
@@ -93,4 +99,38 @@ jobs:
         gh release create "${TAG_NAME}" --title "Operator ${TAG_NAME#release/operator/}" \
           --notes $'Pixie Operator Release:\n'"${changelog}"
         gh release upload "${TAG_NAME}" operator-artifacts/*
+  create-helm-chart:
+    if: ${{ !contains(github.event.ref, '-') }}
+    name: Create Helm chart on Github
+    runs-on: ubuntu-latest
+    needs: build-release
+    concurrency: gh-pages
+    permissions:
+      contents: write
+    steps:
+    - uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3  # v3.5.0
+      with:
+        fetch-depth: 0
+        ref: gh-pages
+    - uses: actions/download-artifact@9bc31d5ccc31df68ecc42ccf4149144866c47d8a  # v3.0.2
+    - name: Setup git
+      shell: bash
+      env:
+        GIT_SSH_COMMAND: "ssh -i /tmp/ssh.key"
+      run: |
+        git config --global user.name 'pixie-io-buildbot'
+        git config --global user.email 'build@pixielabs.ai'
+    - name: Push Helm YAML to gh-pages
+      shell: bash
+      env:
+        TAG_NAME: ${{ github.event.release.tag_name }}
+        GH_TOKEN: ${{ secrets.BUILDBOT_GH_API_TOKEN }}
+        GIT_SSH_COMMAND: "ssh -i /tmp/ssh.key"
+      # yamllint disable rule:indentation
+      run: |
+        cp index-artifacts/index.yaml helm_chart/index.yaml
+        git add helm_chart/index.yaml
+        export VERSION="$(echo "${TAG_NAME}" | cut -d'/' -f3)"
+        git commit -s -m "Release Helm chart ${VERSION}"
+        git push origin "gh-pages"
       # yamllint enable rule:indentation

ci/operator_helm_build_release.sh

@@ -34,6 +34,8 @@ parse_args() {
 parse_args "$@"
 tmp_dir="$(mktemp -d)"
 artifacts_dir="${ARTIFACTS_DIR:?}"
+index_file="${INDEX_FILE:?}"
+gh_repo="${GH_REPO:?}"
 
 helm_gcs_bucket="pixie-operator-charts"
 if [[ $VERSION == *"-"* ]]; then
@@ -88,3 +90,12 @@ cp sha "${artifacts_dir}/pixie-operator-chart-${VERSION}.tgz.sha256"
 
 # Upload the new index and tar to gcs by syncing. This will help keep the timestamps for pre-existing tars the same.
 gsutil rsync "${tmp_dir}/${helm_gcs_bucket}" "gs://${helm_gcs_bucket}"
+
+# Generate separate index file for GH.
+mkdir -p "${tmp_dir}/gh_helm_chart"
+helm package "${helm_path}" -d "${tmp_dir}/gh_helm_chart"
+# Pull index file.
+curl https://artifacts.px.dev/helm_chart/index.yaml -o old_index.yaml
+# Update the index file.
+helm repo index "${tmp_dir}/gh_helm_chart" --merge old_index.yaml --url "https://github.com/${gh_repo}/releases/download/release%2Foperator%2Fv${VERSION}"
+mv "${tmp_dir}/gh_helm_chart/index.yaml" "${index_file}"