update alarm time constraints fail but without helpful error message

[ZhiQiang Fan]

# ceilometer alarm-threshold-update 40fc94d3-a7a1-4e15-b9b7-1ebcbd80058c --time-constraint 'start=30 17 31 3 *;duration=3600'
'name'

# ceilometer -d alarm-threshold-update 40fc94d3-a7a1-4e15-b9b7-1ebcbd80058c --time-constraint 'start=30 17 31 3 *;duration=3600'
Traceback (most recent call last):
  File "/usr/local/bin/ceilometer", line 10, in <module>
    sys.exit(main())
  File "/opt/stack/python-ceilometerclient/ceilometerclient/shell.py", line 299, in main
    CeilometerShell().main(args)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/shell.py", line 248, in main
    args.func(client, args)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/shell.py", line 462, in _wrapped
    return func(*args, **kwargs)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/shell.py", line 190, in wrapped
    return func(cc, args)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/shell.py", line 190, in wrapped
    return func(cc, args)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/shell.py", line 800, in do_alarm_threshold_update
    alarm = cc.alarms.update(args.alarm_id, **fields)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/alarms.py", line 163, in update
    updated.get('time_constraints', []), kwargs)
  File "/opt/stack/python-ceilometerclient/ceilometerclient/v2/alarms.py", line 138, in _merge_time_constraints
    if old_tc['name'] == tc['name']:#tc.get('name'): # if names match, merge
KeyError: 'name'

after fix:
# ceilometer alarm-threshold-update 40fc94d3-a7a1-4e15-b9b7-1ebcbd80058c --time-constraint 'start=30 17 31 3 *;duration=3600'
Invalid input for field/attribute name. Value: 'None'. Mandatory field missing. (HTTP 400) (Request-ID: req-85662cc1-e465-42b4-8d38-690f7ae30a02)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/169774

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/169774
Committed: https://git.openstack.org/cgit/openstack/python-ceilometerclient/commit/?id=16880fcaebb9a950c7ad7ca17ff87b000645f2ac
Submitter: Jenkins
Branch: master

commit 16880fcaebb9a950c7ad7ca17ff87b000645f2ac
Author: ZhiQiang Fan <email address hidden>
Date: Wed Apr 1 22:22:07 2015 +0800

    print user friendly error message for alarm update time constraints

    Currently, if we update an alarm with wrong time constraint which
    doesn't get name defined, then the shell only prints a very simple
    string 'name'.

    This is because our code assume name field has always been specified,
    however it is not true, then KeyError exception will be raised but not
    handled well, finally user only gets an implicit message.

    This patch uses dict.get() for name field, and sends request (may be broken)
    to ceilometer api, then extracts error message from response.

    Change-Id: I086c4ec790acc22767ba7f5e43dbcf73f3af5dff
    Closes-Bug: #1439207