500 on deleteing a not existing ec2 security group

[Attila Fazekas]

Looks like there are 2 reason for seeing 500 errors on not existing ec2 security group delete attempt:

* Unexpected TypeError raised: expected string or buffer
* Unexpected UnboundLocalError raised: local variable 'group' referenced before assignment

Since it is server error the euca2ools automatically and silently retries the request multiple (unlimited?) times.

1. source the ec2 credentials:
$source /opt/stack/new/devstack/accrc/demo/demo

2.a:
$ euca-delete-group --debug 42
...
2015-01-13 09:57:02,907 euca2ools [DEBUG]:Received 500 response. Retrying in 1.9 seconds

2.b:
$ euca-delete-group --debug fortytwo

Relevant lines from the n-api log (It does not contains a full trace, however on this kind of errors it should):

action: DeleteSecurityGroup __call__ /opt/stack/new/nova/nova/api/ec2/__init__.py:379
arg: GroupName val: fortytwo __call__ /opt/stack/new/nova/nova/api/ec2/__init__.py:382
Neutron security group fortytwo not found get /opt/stack/new/nova/nova/network/security_group/neutron_driver.py:138
Unexpected UnboundLocalError raised: local variable 'group' referenced before assignment
EC2 error response: UnboundLocalError: Unknown error occurred. ec2_error_response /opt/stack/new/nova/nova/api/ec2/faults.py:29

Note: The issue seen in a neutron setup.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/148459

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/148459
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=9ff47340292c374ea7ab623e3405b0ae71de0919
Submitter: Jenkins
Branch: master

commit 9ff47340292c374ea7ab623e3405b0ae71de0919
Author: liyingjun <email address hidden>
Date: Tue Jan 20 15:45:56 2015 +0800

    Fix 500 when deleting a not existing ec2 security group

    There are 2 reason for seeing 500 errors on not existing ec2 security
    group delete attempt:

    * Unexpected TypeError raised: expected string or buffer
    * Unexpected UnboundLocalError raised: local variable 'group' referenced
      before assignment

    Fix the problems by catching the TypeError and raising NotFound
    exception explicitly.

    Change-Id: Iab9a4f99b965dbdd3419ea7585e8a4988eb738ae
    Closes-bug: #1410172