fix workflow

.gitea/workflows/build.yaml

@@ -1,36 +1,38 @@
-name: Build fdroidserver-ipfs image
+# ci-images/fdroidserver-ipfs/.gitea/workflows/build.yaml
+#
+# Daily check, build ONLY when the upstream base or the Dockerfile changed.
+# See the flutter-node variant for the full explanation - identical logic,
+# one upstream base instead of two.
+
+name: build
 
-# Triggers:
-#   - push to main           → immediate rebuild (any change in the repo)
-#   - weekly cron            → picks up upstream :master refreshes in
-#                              docker-executable-fdroidserver without a
-#                              source change here
-#   - manual dispatch        → on-demand
 on:
+  schedule:
+    - cron: "0 4 * * *"
   push:
     branches: [main]
-  schedule:
-    # Sun 04:00 UTC.
-    - cron: "0 4 * * 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/fdroidserver-ipfs
+  FDROIDSERVER_IMAGE: registry.gitlab.com/fdroid/docker-executable-fdroidserver:master
 
 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 below.
-    if: vars.REGISTRY_HOST != ''
+  check:
     runs-on: ubuntu-docker
-    permissions:
-      packages: write
+    outputs:
+      changed: ${{ steps.cmp.outputs.changed }}
+      hash:    ${{ steps.hash.outputs.hash }}
+      base:    ${{ steps.up.outputs.base }}
+      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
@@ -38,15 +40,69 @@ jobs:
       - 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: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Resolve upstream digest
+        id: up
+        run: |
+          set -euo pipefail
+          b=$(docker buildx imagetools inspect "$FDROIDSERVER_IMAGE" --format '{{.Manifest.Digest}}')
+          echo "base=$b" >> "$GITHUB_OUTPUT"
+          echo "base: $b"
+
+      - name: Compute input hash
+        id: hash
+        run: |
+          set -euo pipefail
+          h=$(printf '%s\n' \
+                "${{ steps.up.outputs.base }}" \
+                "$(sha256sum Dockerfile | cut -d' ' -f1)" \
+              | sha256sum | cut -c1-12)
+          echo "hash=$h" >> "$GITHUB_OUTPUT"
+          echo "input hash: $h"
+
+      - name: Compare against what is already published
+        id: cmp
+        run: |
+          set -euo pipefail
+          if [ "${{ 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: ${{ gitea.actor }}
+          username: ${{ github.actor }}
           password: ${{ secrets.REGISTRY_TOKEN }}
 
       - name: Build and push
@@ -54,13 +110,18 @@ jobs:
         with:
           context: .
           push: true
-          # Two tags:
-          #   :stable     — moving, what callers pull by default
-          #   :YYYYMMDD   — immutable, for pinning / rollback
-          tags: |
-            ${{ vars.REGISTRY_HOST }}/ci-images/fdroidserver-ipfs:stable
-            ${{ vars.REGISTRY_HOST }}/ci-images/fdroidserver-ipfs:${{ steps.date.outputs.date }}
+          pull: true
+          provenance: false
+          cache-from: type=registry,ref=${{ env.IMAGE }}:stable
+          cache-to: type=inline
           build-args: |
             IMAGE_SOURCE=https://${{ vars.REGISTRY_HOST }}/ci-images/fdroidserver-ipfs
-          cache-from: type=registry,ref=${{ vars.REGISTRY_HOST }}/ci-images/fdroidserver-ipfs:stable
-          cache-to: type=inline
+            FDROIDSERVER_IMAGE=${{ env.FDROIDSERVER_IMAGE }}@${{ needs.check.outputs.base }}
+          labels: |
+            org.opencontainers.image.base.name=${{ env.FDROIDSERVER_IMAGE }}
+            org.opencontainers.image.base.digest=${{ needs.check.outputs.base }}
+            org.opencontainers.image.revision=${{ github.sha }}
+          tags: |
+            ${{ env.IMAGE }}:stable
+            ${{ env.IMAGE }}:${{ needs.check.outputs.date }}
+            ${{ env.IMAGE }}:src-${{ needs.check.outputs.hash }}