Return the exit code of the executed command

On the container exec command, return the same exit code of
the command being executed in the container. This would be
useful for users to retrieve the exit code as they did in
Docker CLI.

Change-Id: I2aa0b4d9e7994a125f54e93d36efc854db66fe25
Depends-On: I20cc48da20bdc3784ec8fce4e38a98baf388a0ca
Closes-Bug: #1645044

zunclient/osc/v1/containers.py

@@ -386,8 +386,11 @@ class ExecContainer(command.Command):
         client = _get_client(self, parsed_args)
         container = parsed_args.container
         command = ' '.join(parsed_args.command)
-        output = client.containers.execute(container, command)
+        response = client.containers.execute(container, command)
+        output = response['output']
+        exit_code = response['exit_code']
         print(output)
+        return exit_code
 
 
 class LogsContainer(command.Command):

zunclient/shell.py

@@ -573,7 +573,7 @@ class OpenStackZunShell(object):
                                 endpoint_type=endpoint_type,
                                 insecure=insecure)
 
-        args.func(self.cs, args)
+        return args.func(self.cs, args)
 
     def _dump_timings(self, timings):
         class Tyme(object):
@@ -631,8 +631,8 @@ class OpenStackHelpFormatter(argparse.HelpFormatter):
 
 def main():
     try:
-        OpenStackZunShell().main(map(encodeutils.safe_decode, sys.argv[1:]))
-
+        return OpenStackZunShell().main(
+            map(encodeutils.safe_decode, sys.argv[1:]))
     except Exception as e:
         logger.debug(e, exc_info=1)
         print("ERROR: %s" % encodeutils.safe_encode(six.text_type(e)),
@@ -641,4 +641,4 @@ def main():
 
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main())

zunclient/v1/containers_shell.py

@@ -359,8 +359,11 @@ def do_logs(cs, args):
            help='The command to execute in a container')
 def do_exec(cs, args):
     """Execute command in a container."""
-    output = cs.containers.execute(args.container, ' '.join(args.command))
+    response = cs.containers.execute(args.container, ' '.join(args.command))
+    output = response['output']
+    exit_code = response['exit_code']
     print(output)
+    return exit_code
 
 
 @utils.arg('containers',