Add support for collect-timing option

When we run "cinder help" we can see that there is a --collect-timing
option:

  --collect-timing Collect per-API call timing information.

This is a keystone session option that we are not currently acting on
from a user perspective.

This patch adds support for this option, and we'll be able to see the
timing in a similar way as we do with OSC:

$ cinder --collect-timing api-version
+------+---------+---------+-------------+
| ID   | Status  | Version | Min_version |
+------+---------+---------+-------------+
| v3.0 | CURRENT | 3.66    | 3.0         |
+------+---------+---------+-------------+
+--------+------------------------------------------------+----------+
| method | url                                            | seconds  |
+--------+------------------------------------------------+----------+
| GET    | http://192.168.121.243/identity                | 0.003591 |
| POST   | http://192.168.121.243/identity/v3/auth/tokens | 0.016649 |
| GET    | http://192.168.121.243/volume/                 | 0.004012 |
| GET    | http://192.168.121.243/volume/                 | 0.004543 |
+--------+------------------------------------------------+----------+

The patch formats the "elapsed" time attribute into seconds and renames
the column to "seconds" to make it more user friendly similar to OSC.
If we didn't it would look like 0:00:00.003744

Closes-Bug: #1960337
Change-Id: Ia6b31794bf60a351007cc4476a76b9bcb76bf378

cinderclient/shell.py

@@ -705,6 +705,12 @@ class OpenStackCinderShell(object):
         if not auth_session:
             auth_session = self._get_keystone_session()
 
+        # collect_timing is a keystone session option
+        if (not isinstance(auth_session, session.Session)
+                and getattr(args, 'collect_timing', False) is True):
+            raise exc.AuthorizationFailure("Provided auth plugin doesn't "
+                                           "support collect_timing option")
+
         insecure = self.options.insecure
 
         client_args = dict(
@@ -805,6 +811,17 @@ class OpenStackCinderShell(object):
                 print("To display trace use next command:\n"
                       "osprofiler trace show --html %s " % trace_id)
 
+            if getattr(args, 'collect_timing', False) is True:
+                self._print_timings(auth_session)
+
+    def _print_timings(self, session):
+        timings = session.get_timings()
+        utils.print_list(
+            timings,
+            fields=('method', 'url', 'seconds'),
+            sortby_index=None,
+            formatters={'seconds': lambda r: r.elapsed.total_seconds()})
+
     def _discover_client(self,
                          current_client,
                          os_api_version,

releasenotes/notes/collect-timing-ce6d521d40d422fb.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    `Bug #1960337 <https://bugs.launchpad.net/cinder/+bug/1960337>`_: Added
+    support for ``collect-timing`` parameter to see the timings of REST API
+    requests from the client when using Keystone authentication.