54 - Skip CI image rebuild when the lockfile tag already exists

.forgejo/workflows/ci.yml

@@ -32,7 +32,27 @@ jobs:
           HASH="$(sha256sum composer.lock | cut -c1-12)"
           echo "tag=php8.3-${HASH}" >> "$GITHUB_OUTPUT"
 
+      - name: Check whether image already exists
+        id: exists
+        run: |
+          set -euo pipefail
+          TOKEN="$(curl -sf "https://forge.lvl0.xyz/v2/token?service=container_registry&scope=repository:lvl0/dishplanner-ci:pull" | grep -o '"token":"[^"]*"' | head -n1 | cut -d'"' -f4)"
+          if [ -z "$TOKEN" ]; then
+            echo "Registry token fetch failed; cannot check for an existing image." >&2
+            exit 1
+          fi
+          CODE="$(curl -s -o /dev/null -w '%{http_code}' \
+            -H "Authorization: Bearer $TOKEN" \
+            -H 'Accept: application/vnd.oci.image.index.v1+json, application/vnd.docker.distribution.manifest.list.v2+json, application/vnd.docker.distribution.manifest.v2+json' \
+            "https://forge.lvl0.xyz/v2/lvl0/dishplanner-ci/manifests/${{ steps.meta.outputs.tag }}")"
+          if [ "$CODE" = "200" ]; then
+            echo "found=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "found=false" >> "$GITHUB_OUTPUT"
+          fi
+
       - name: Build and push CI image
+        if: steps.exists.outputs.found == 'false'
         uses: https://data.forgejo.org/docker/build-push-action@v5
         with:
           context: .