ci: auto-build runner images on Dockerfile changes

- Watches Dockerfile.golang, .rust, .node for changes
- Builds and pushes images to Forgejo registry with commit SHA + latest tags
- Image Updater detects new images automatically
- ArgoCD syncs updated image tags
- Workflow runs on: golang (has docker + dind)

.gitea/workflows/build-runner-images.yml

@@ -0,0 +1,67 @@
+name: Build and push runner images
+
+on:
+  push:
+    paths:
+      - 'k8s/infra/forgejo-runner/Dockerfile.golang'
+      - 'k8s/infra/forgejo-runner/Dockerfile.rust'
+      - 'k8s/infra/forgejo-runner/Dockerfile.node'
+    branches:
+      - main
+
+jobs:
+  build-runners:
+    runs-on: golang
+    env:
+      REGISTRY: forgejo.riotpiao.com
+      IMAGE_BASE: forgejo.riotpiao.com/rock
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Get short SHA
+        id: sha
+        run: |
+          SHORT_SHA=$(git rev-parse --short HEAD)
+          echo "short_sha=${SHORT_SHA}" >> $GITHUB_OUTPUT
+
+      - name: Registry login
+        run: |
+          echo "${REGISTRY_TOKEN}" | docker login "${REGISTRY}" \
+            --username "${REGISTRY_USER}" --password-stdin
+        env:
+          REGISTRY_USER: ${{ secrets.FORGEJO_REGISTRY_USER }}
+          REGISTRY_TOKEN: ${{ secrets.FORGEJO_REGISTRY_TOKEN }}
+
+      - name: Build and push golang-runner
+        if: contains(github.event.head_commit.modified, 'Dockerfile.golang')
+        run: |
+          docker build -f k8s/infra/forgejo-runner/Dockerfile.golang \
+            -t "${IMAGE_BASE}/forgejo-runner-golang:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE_BASE}/forgejo-runner-golang:latest" \
+            .
+          docker push "${IMAGE_BASE}/forgejo-runner-golang:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE_BASE}/forgejo-runner-golang:latest"
+          echo "✓ Pushed golang-runner"
+
+      - name: Build and push rust-runner
+        if: contains(github.event.head_commit.modified, 'Dockerfile.rust')
+        run: |
+          docker build -f k8s/infra/forgejo-runner/Dockerfile.rust \
+            -t "${IMAGE_BASE}/forgejo-runner-rust:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE_BASE}/forgejo-runner-rust:latest" \
+            .
+          docker push "${IMAGE_BASE}/forgejo-runner-rust:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE_BASE}/forgejo-runner-rust:latest"
+          echo "✓ Pushed rust-runner"
+
+      - name: Build and push node-runner
+        if: contains(github.event.head_commit.modified, 'Dockerfile.node')
+        run: |
+          docker build -f k8s/infra/forgejo-runner/Dockerfile.node \
+            -t "${IMAGE_BASE}/forgejo-runner-node:${{ steps.sha.outputs.short_sha }}" \
+            -t "${IMAGE_BASE}/forgejo-runner-node:latest" \
+            .
+          docker push "${IMAGE_BASE}/forgejo-runner-node:${{ steps.sha.outputs.short_sha }}"
+          docker push "${IMAGE_BASE}/forgejo-runner-node:latest"
+          echo "✓ Pushed node-runner"