ci: add helm OCI release flow (#1)

.github/workflows/helm-oci.yaml

@@ -0,0 +1,77 @@
+name: Release Helm Charts
+
+on:
+  push:
+    branches:
+      - 'main'
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - 'main'
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Set up Helm
+        uses: azure/setup-helm@5119fcb9089d432beecbf79bb2c7915207344b78 # v3.5
+        with:
+          version: v3.12.0
+
+      - name: Set chart name
+        id: chart-name
+        run: echo "value=${{ github.event.repository.name }}" >> "$GITHUB_OUTPUT"
+
+      - name: Set OCI registry name
+        id: oci-registry-name
+        run: echo "value=ghcr.io/${{ github.repository_owner }}/helm-charts" >> "$GITHUB_OUTPUT"
+
+      - name: Set OCI chart name
+        id: oci-chart-name
+        run: echo "value=${{ steps.oci-registry-name.outputs.value }}/${{ steps.chart-name.outputs.value }}" >> "$GITHUB_OUTPUT"
+
+      - name: Helm lint
+        run: helm lint charts/${{ steps.chart-name.outputs.value }}
+
+      - name: Determine raw version
+        uses: haya14busa/action-cond@1d6e8a12b20cdb4f1954feef9aa475b9c390cab5 # v1.1.1
+        id: raw-version
+        with:
+          cond: ${{ github.ref_type == 'tag' }}
+          if_true: ${{ github.ref_name }}
+          if_false: v0.0.0
+
+      - name: Determine version
+        id: version
+        run: |
+          VERSION=${{ steps.raw-version.outputs.value }}
+          echo "value=${VERSION#v}" >> "$GITHUB_OUTPUT"
+
+      - name: Helm package
+        id: build
+        run: |
+          helm package charts/${{ steps.chart-name.outputs.value }} --version ${{ steps.version.outputs.value }} --app-version ${{ steps.raw-version.outputs.value }}
+          echo "package=${{ steps.chart-name.outputs.value }}-${{ steps.version.outputs.value }}.tgz" >> "$GITHUB_OUTPUT"
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@343f7c4344506bcbf9b4de18042ae17996df046d # v3.0.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ github.token }}
+        if: github.ref_type == 'tag'
+
+      - name: Helm push
+        run: helm push ${{ steps.build.outputs.package }} oci://${{ steps.oci-registry-name.outputs.value }}
+        env:
+          HELM_REGISTRY_CONFIG: ~/.docker/config.json
+        if: github.ref_type == 'tag'