[autotest] Get atest to list the shard a host is on. TEST=Ran atest host list. BUG=chromium:438858 Change-Id: I0ec46f1d3f8068c0f2144a8a0e5a769cf81a0c96 Reviewed-on: https://chromium-review.googlesource.com/235545 Reviewed-by: Prashanth B <[email protected]> Tested-by: Prashanth B <[email protected]> Commit-Queue: Prashanth B <[email protected]> Trybot-Ready: Prashanth B <[email protected]>

diff --git a/cli/topic_common.py b/cli/topic_common.py
index f4cb0ba..c9c0a7f 100644
--- a/cli/topic_common.py
+++ b/cli/topic_common.py

@@ -108,6 +108,7 @@
                     'max_number_of_machines': 'Max. hosts to use',
                     'parse_failed_repair': 'Include failed repair results',
                     'atomic_group.name': 'Atomic Group Name',
+                    'shard': 'Shard',
                     }
 
 # In the failure, tag that will replace the item.
@@ -138,7 +139,8 @@
                 'invalid': lambda flag: str(bool(not flag)),
                 'only_if_needed': _int_2_bool_string,
                 'platform': __convert_platform,
-                'labels': lambda labels: ', '.join(labels)}
+                'labels': lambda labels: ', '.join(labels),
+                'shards': lambda shard: shard.hostname if shard else ''}
 
 
 def _get_item_key(item, key):