Initial draft of Gitea-oriented actions

.gitea/workflows/build-push-docker.yml

@@ -0,0 +1,65 @@
+name: Publish Docker Image
+
+on:
+  workflow_call:
+    inputs:
+      release:
+        required: true
+        type: string
+    outputs:
+      success:
+        description: "Did the flow succeed?"
+        value: ${{ jobs.publish.outputs.success }}
+
+env:
+  REGISTRY_URL: git.tainton.uk
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    # permissions:
+    #   packages: write
+    #   contents: read
+    #   attestations: write
+    #   id-token: write
+    outputs:
+      success: ${{ steps.set_flag.outputs.success }}
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v4.1.7
+        with:
+          ref: ${{ inputs.release }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Gitea Package Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY_URL }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.GITEA_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ${{ env.REGISTRY_URL }}/${{ gitea.repository }}
+          tags: |
+            type=semver,pattern=v{{version}},value=${{ inputs.release }}
+
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          labels: ${{ steps.meta.outputs.labels }}
+          tags: |
+            ${{ env.REGISTRY_URL }}/${{ gitea.repository }}:latest
+            ${{ env.REGISTRY_URL }}/${{ gitea.repository }}:${{ inputs.release }}
+
+      - name: Set success flag
+        id: set_flag
+        run: echo "success=true" >> "$GITEA_OUTPUT"