use action run number for docker image tag

Author: m-parkhill

.github/workflows/docker-publish.yml

@@ -24,6 +24,8 @@ jobs:
   build-and-push:
     name: Build and Push truvera-api-mcp
     runs-on: ubuntu-latest
+    env:
+      SHOULD_PUSH: ${{ github.event_name != 'workflow_dispatch' || inputs.push }}
     permissions:
       contents: read
       packages: write
@@ -35,15 +37,21 @@ jobs:
       - name: Read build number
         id: build_number
         run: |
-          BUILD_NUM=$(cat apps/truvera-api/.buildnumber)
+          if [ -f apps/truvera-api/.buildnumber ]; then
+            BUILD_NUM=$(cat apps/truvera-api/.buildnumber)
+            echo "Using apps/truvera-api/.buildnumber"
+          else
+            BUILD_NUM="${{ github.run_number }}"
+            echo "apps/truvera-api/.buildnumber not found; using GitHub run number"
+          fi
           echo "build_number=$BUILD_NUM" >> $GITHUB_OUTPUT
           echo "Build number: $BUILD_NUM"
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
       - name: Log in to DockerHub
-        if: github.event_name != 'pull_request'
+        if: ${{ env.SHOULD_PUSH == 'true' }}
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
@@ -63,11 +71,12 @@ jobs:
             type=sha,prefix={{branch}}-
 
       - name: Build and push API Docker image
+        id: docker_build
         uses: docker/build-push-action@v5
         with:
           context: .
           file: ./apps/truvera-api/Dockerfile
-          push: ${{ github.event_name != 'pull_request' && (github.event.inputs.push == 'true' || github.event.inputs.push == null) }}
+          push: ${{ env.SHOULD_PUSH == 'true' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |
@@ -77,4 +86,9 @@ jobs:
           platforms: linux/amd64,linux/arm64
 
       - name: Image digest
+        if: ${{ env.SHOULD_PUSH == 'true' }}
         run: echo "Image pushed with digest ${{ steps.docker_build.outputs.digest }}"
+
+      - name: Image build only
+        if: ${{ env.SHOULD_PUSH != 'true' }}
+        run: echo "Image built without push because workflow_dispatch input 'push' was false"