Added support for override command directive when conductor is building image

Author: Daniil Trishkin

container/core.py

@@ -713,6 +713,13 @@ def _run_intermediate_build_container(engine, container_name, cur_image_id, serv
         environment=dict(ANSIBLE_CONTAINER=1)
     )
 
+    if service.get('build_overrides'):
+        for key in service['build_overrides']:
+            if key in ['user', 'working_dir', 'command', 'privileged']:
+                run_kwargs[key] = service['build_overrides'][key]
+
+        run_kwargs['environment'].update(service['build_overrides']['environment'])
+
     if service.get('volumes'):
         for volume in service['volumes']:
             pieces = volume.split(':')