build_ds_container.py: Enable container image push

Add option to use a k8s container image to create Profile Bundles.
This makes it easy to reference any k8s content image to create Profile
Bundles for OCP4 and RHCOS4.

utils/build_ds_container.py

@@ -42,6 +42,11 @@
         '--product and --debug flags.'),
     action='store_true',
     default=False)
+parser.add_argument(
+    '-i', '--push-content-image',
+    help=(
+        'Do not build any content. Create profile bundles from the referenced k8s content image'),
+    )
 parser.add_argument(
     '-d', '--debug',
     help=(
@@ -270,6 +275,10 @@ def get_image_repository():
     return image_repo.decode().strip()
 
 
+if args.push_content_image:
+    create_profile_bundles(args.products, args.push_content_image)
+    sys.exit(0)
+
 log.info(f'Building content for {", ".join(args.products)}')
 ensure_namespace_exists()