fix(bake): set correct output

Author: jobcespedes

buildx-bake/merge/action.yml

@@ -68,9 +68,6 @@ runs:
 
         print(f"Merged digests:\n{json.dumps(merged, indent=2)}", flush=True)
 
-        with open(os.environ["GITHUB_OUTPUT"], "a") as gh:
-            gh.write(f"image-digests={json.dumps(merged)}\n")
-
         # --- Load bake metadata ---
         with open(bake_meta_path) as f:
             bake_meta = json.load(f)
@@ -84,13 +81,26 @@ runs:
             subprocess.run(cmd, check=True)
 
         # --- Create manifest lists, push & inspect ---
+        image_digests = []
         for entry in merged.values():
             image_name = entry["name"]
             digests = [f"{image_name}@{d}" for d in entry["digests"]]
             tag_args = [a for s in tag_suffixes for a in ("-t", f"{image_name}:{s}")]
-            run(["docker", "buildx", "imagetools", "create"] + tag_args + digests)
+            run(["docker", "buildx", "imagetools", "create", *tag_args, *digests])
             if version:
-                run(["docker", "buildx", "imagetools", "inspect", f"{image_name}:{version}"])
+                ref = f"{image_name}:{version}"
+                result = subprocess.run(
+                    ["docker", "buildx", "imagetools", "inspect", ref,
+                     "--format", "{{.Manifest.Digest}}"],
+                    capture_output=True, text=True, check=True,
+                )
+                digest = result.stdout.strip()
+                print(f"{ref} -> {digest}", flush=True)
+                image_digests.append({image_name: digest})
 
         if not version:
             print("WARNING: DOCKER_META_VERSION not found, skipping inspect")
+
+        print(f"\nimage-digests:\n{json.dumps(image_digests, indent=2)}", flush=True)
+        with open(os.environ["GITHUB_OUTPUT"], "a") as gh:
+            gh.write(f"image-digests={json.dumps(image_digests)}\n")