feat: publish helm chart to helm.coder.com (#4793)

.github/workflows/release.yaml

@@ -20,6 +20,8 @@ permissions:
   contents: write
   # Necessary to push docker images to ghcr.io.
   packages: write
+  # Necessary for GCP authentication (https://github.com/google-github-actions/setup-gcloud#usage)
+  id-token: write
 
 env:
   CODER_RELEASE: ${{ github.event.inputs.snapshot && 'false' || 'true' }}
@@ -167,6 +169,26 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Authenticate to Google Cloud
+        uses: google-github-actions/auth@v0
+        with:
+          workload_identity_provider: ${{ secrets.GCP_WORKLOAD_ID_PROVIDER }}
+          service_account: ${{ secrets.GCP_SERVICE_ACCOUNT }}
+
+      - name: Setup GCloud SDK
+        uses: 'google-github-actions/setup-gcloud@v0'
+
+      - name: Publish Helm Chart
+        run: |
+          set -euo pipefail
+          version="$(./scripts/version.sh)"
+          mkdir -p build/helm
+          cp "build/coder_helm_${version}.tgz" build/helm
+          gsutil cp gs://helm.coder.com/v2/index.yaml build/helm/index.yaml
+          helm repo index build/helm --url https://helm.coder.com/v2 --merge build/helm/index.yaml
+          gsutil -h "Cache-Control:no-cache,max-age=0" cp build/helm/coder_helm_${version}.tgz gs://helm.coder.com/v2
+          gsutil -h "Cache-Control:no-cache,max-age=0" cp build/helm/index.yaml gs://helm.coder.com/v2
+
       - name: Upload artifacts to actions (if dry-run or snapshot)
         if: ${{ github.event.inputs.dry_run || github.event.inputs.snapshot }}
         uses: actions/upload-artifact@v2