Update .gitea/workflows/build.yaml

.gitea/workflows/build.yaml

@@ -1,38 +1,48 @@
-name: Build flutter-node image
+# ci-images/flutter-node/.gitea/workflows/build.yaml
+#
+# Daily check, build ONLY when an input actually changed.
+#
+# Inputs that define an image:  upstream base digests + the Dockerfile itself.
+# Their combined hash is published as a marker tag `src-<hash>` next to the image.
+# If that tag already exists in the registry, this exact image was already built
+# and the run stops before doing any work.
+#
+# Tags pushed on a real build:
+#   :stable      moving, what runners pull by default
+#   :YYYYMMDD    immutable, for pinning / rollback
+#   :src-<hash>  marker, 856 bytes, makes the next check a single registry lookup
+
+name: build
 
-# Triggers:
-#   - push to main           → immediate rebuild (any change in the repo)
-#   - weekly cron            → picks up upstream patch updates in
-#                              cirruslabs/flutter:stable and node:20
-#                              without a source change
-#   - manual dispatch        → on-demand
 on:
+  schedule:
+    - cron: "0 3 * * *"          # daily instead of weekly - costs nothing when nothing changed
   push:
     branches: [main]
-  schedule:
-    # Sun 03:00 UTC. cirruslabs typically ships :stable bumps a few
-    # hours after the upstream Flutter stable channel — adjust freely.
-    - cron: "0 3 * * 0"
   workflow_dispatch:
+    inputs:
+      force:
+        description: "Build even if no upstream change was detected"
+        type: boolean
+        default: false
+
+env:
+  IMAGE: ${{ vars.REGISTRY_HOST }}/ci-images/flutter-node
+  FLUTTER_IMAGE: ghcr.io/cirruslabs/flutter:stable
+  NODE_IMAGE: node:20-bookworm-slim
 
 jobs:
-  build:
-    # Skip the job entirely (no runner provisioning) when the registry
-    # host isn't configured — shows as "skipped" in the UI rather than
-    # burning minutes on a build that can't be pushed. Secrets can't be
-    # referenced in job-level if:, so REGISTRY_TOKEN is still checked
-    # in the first step below.
-    if: vars.REGISTRY_HOST != ''
+  check:
     runs-on: ubuntu-docker
-    permissions:
-      packages: write
+    outputs:
+      changed:  ${{ steps.cmp.outputs.changed }}
+      hash:     ${{ steps.hash.outputs.hash }}
+      flutter:  ${{ steps.up.outputs.flutter }}
+      node:     ${{ steps.up.outputs.node }}
+      date:     ${{ steps.date.outputs.date }}
     steps:
       - name: Validate registry token
-        run: |
-          if [ -z "${{ secrets.REGISTRY_TOKEN }}" ]; then
-            echo "::error::Missing required config: secrets.REGISTRY_TOKEN"
-            exit 1
-          fi
+        run: test -n "${{ secrets.REGISTRY_TOKEN }}" || { echo "REGISTRY_TOKEN missing"; exit 1; }
 
       - name: Checkout
         uses: actions/checkout@v4
@@ -40,18 +50,75 @@ jobs:
       - name: Set up Buildx
         uses: docker/setup-buildx-action@v3
 
-      - name: Compute date tag
-        id: date
-        run: echo "date=$(date -u +%Y%m%d)" >> "$GITHUB_OUTPUT"
-
-      # Same registry + PAT pattern other projects on this Gitea
-      # instance use. The auto-injected gitea token is rejected by the
-      # registry path, hence the manually-issued PAT in REGISTRY_TOKEN.
       - name: Log in to Gitea registry
         uses: docker/login-action@v3
         with:
           registry: ${{ vars.REGISTRY_HOST }}
-          username: ${{ gitea.actor }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      # Resolve the mutable upstream tags to immutable digests, right now.
+      - name: Resolve upstream digests
+        id: up
+        run: |
+          set -euo pipefail
+          f=$(docker buildx imagetools inspect "$FLUTTER_IMAGE" --format '{{.Manifest.Digest}}')
+          n=$(docker buildx imagetools inspect "$NODE_IMAGE"    --format '{{.Manifest.Digest}}')
+          echo "flutter=$f" >> "$GITHUB_OUTPUT"
+          echo "node=$n"    >> "$GITHUB_OUTPUT"
+          echo "flutter: $f"
+          echo "node:    $n"
+
+      - name: Compute input hash
+        id: hash
+        run: |
+          set -euo pipefail
+          h=$(printf '%s\n' \
+                "${{ steps.up.outputs.flutter }}" \
+                "${{ steps.up.outputs.node }}" \
+                "$(sha256sum Dockerfile | cut -d' ' -f1)" \
+              | sha256sum | cut -c1-12)
+          echo "hash=$h" >> "$GITHUB_OUTPUT"
+          echo "input hash: $h"
+
+      # The whole gate: does a marker tag for this exact input set already exist?
+      - name: Compare against what is already published
+        id: cmp
+        run: |
+          set -euo pipefail
+          if [ "${{ github.event_name }}" != "schedule" ] || [ "${{ inputs.force }}" = "true" ]; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            echo "non-scheduled or forced run - building"
+            exit 0
+          fi
+          if docker buildx imagetools inspect "$IMAGE:src-${{ steps.hash.outputs.hash }}" >/dev/null 2>&1; then
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+            echo "no change since last build - skipping"
+          else
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            echo "upstream or Dockerfile changed - building"
+          fi
+
+      - name: Compute date tag
+        id: date
+        run: echo "date=$(date -u +%Y%m%d)" >> "$GITHUB_OUTPUT"
+
+  build:
+    needs: check
+    if: needs.check.outputs.changed == 'true'
+    runs-on: ubuntu-docker
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Gitea registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ vars.REGISTRY_HOST }}
+          username: ${{ github.actor }}
           password: ${{ secrets.REGISTRY_TOKEN }}
 
       - name: Build and push
@@ -59,13 +126,19 @@ jobs:
         with:
           context: .
           push: true
-          # Two tags:
-          #   :stable     — moving, what runners pull by default
-          #   :YYYYMMDD   — immutable, for pinning / rollback
-          tags: |
-            ${{ vars.REGISTRY_HOST }}/ci-images/flutter-node:stable
-            ${{ vars.REGISTRY_HOST }}/ci-images/flutter-node:${{ steps.date.outputs.date }}
+          pull: true                      # re-resolve bases; without this the cron is a no-op
+          provenance: false               # no attestation manifest -> half the package versions
+          cache-from: type=registry,ref=${{ env.IMAGE }}:stable
+          cache-to: type=inline
           build-args: |
             IMAGE_SOURCE=https://${{ vars.REGISTRY_HOST }}/ci-images/flutter-node
-          cache-from: type=registry,ref=${{ vars.REGISTRY_HOST }}/ci-images/flutter-node:stable
-          cache-to: type=inline
+            FLUTTER_IMAGE=${{ env.FLUTTER_IMAGE }}@${{ needs.check.outputs.flutter }}
+            NODE_IMAGE=${{ env.NODE_IMAGE }}@${{ needs.check.outputs.node }}
+          labels: |
+            org.opencontainers.image.base.name=${{ env.FLUTTER_IMAGE }}
+            org.opencontainers.image.base.digest=${{ needs.check.outputs.flutter }}
+            org.opencontainers.image.revision=${{ github.sha }}
+          tags: |
+            ${{ env.IMAGE }}:stable
+            ${{ env.IMAGE }}:${{ needs.check.outputs.date }}
+            ${{ env.IMAGE }}:src-${{ needs.check.outputs.hash }}