Use temporary file to pass digest

Author: JarLob

.github/workflows/release.yml

@@ -35,7 +35,8 @@ jobs:
         id: docker_build
         run: |
           echo ${{ secrets.GITHUB_TOKEN }} | docker login ghcr.io -u ${{ github.actor }} --password-stdin
-          DIGEST=$(python release_tools/publish_docker.py release.txt main.py ${{ env.REGISTRY }}/${{ env.USER }}/${{ env.IMAGE_NAME }} ${{ github.event.inputs.release_tag }} | grep '^Image digest: ' | cut -d':' -f2 | xargs)
+          python release_tools/publish_docker.py release.txt main.py ${{ env.REGISTRY }}/${{ env.USER }}/${{ env.IMAGE_NAME }} ${{ github.event.inputs.release_tag }}
+          DIGEST=$(cat /tmp/digest.txt)
           echo "digest=$DIGEST" >> $GITHUB_OUTPUT
 
       - name: Generate artifact attestation

release_tools/publish_docker.py

@@ -103,7 +103,9 @@ def build_and_push_image(dest_dir, image_name, tag):
     ], check=True)
     print(f"Pushed {image_name}:{tag}")
     digest = get_image_digest(image_name, tag)
-    print(f"Image digest: {digest}") # The prefix "Image digest: " is used for grepping in the release workflow
+    print(f"Image digest: {digest}")
+    with open("/tmp/digest.txt", "w") as f:
+        f.write(digest)
 
 if __name__ == "__main__":
     if len(sys.argv) != 5: