unable to reload allocations neutron-dhcp-agent

[Miguel Angel Ajo]

In some cases dhcp agent dumps an exception because it's trying to use replace_file over a directory
which was never created.

http://logstash.openstack.org/#eyJzZWFyY2giOiJcIlVuYWJsZSB0byByZWxvYWRfYWxsb2NhdGlvbnMgZGhjcCBmb3JcIiIsImZpZWxkcyI6WyJsb2dfdXJsIl0sIm9mZnNldCI6MCwidGltZWZyYW1lIjoiNjA0ODAwIiwiZ3JhcGhtb2RlIjoiY291bnQiLCJ0aW1lIjp7InVzZXJfaW50ZXJ2YWwiOjB9LCJzdGFtcCI6MTQyMDQ1MDU0OTY2M30=

[req-84e8f66a-5401-424c-82d5-068267d81c7b None] Unable to reload_allocations dhcp for c2a866cf-a1db-4e50-9fc8-5da8b7320669.
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent Traceback (most recent call last):
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/opt/stack/new/neutron/neutron/agent/dhcp_agent.py", line 129, in call_driver
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent getattr(driver, action)(**action_kwargs)
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/opt/stack/new/neutron/neutron/agent/linux/dhcp.py", line 445, in reload_allocations
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent self._output_hosts_file()
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/opt/stack/new/neutron/neutron/agent/linux/dhcp.py", line 525, in _output_hosts_file
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent utils.replace_file(filename, buf.getvalue())
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/opt/stack/new/neutron/neutron/agent/linux/utils.py", line 112, in replace_file
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent tmp_file = tempfile.NamedTemporaryFile('w+', dir=base_dir, delete=False)
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/usr/lib/python2.7/tempfile.py", line 462, in NamedTemporaryFile
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags)
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/usr/lib/python2.7/tempfile.py", line 239, in _mkstemp_inner
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent fd = _os.open(file, flags, 0600)
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent File "/usr/local/lib/python2.7/dist-packages/eventlet/green/os.py", line 109, in open
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent fd = __original_open__(file, flags, mode)
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent OSError: [Errno 2] No such file or directory: '/opt/stack/data/neutron/dhcp/c2a866cf-a1db-4e50-9fc8-5da8b7320669/tmpJnpUfM'
2015-01-05 09:06:38.554 2489 TRACE neutron.agent.dhcp_agent

Proper directory creation must always happen before any attempt to "replace_file"

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/144977

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/144977
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=057e540087150d57a2e628b5f08dcdaa8b43a307
Submitter: Jenkins
Branch: master

commit 057e540087150d57a2e628b5f08dcdaa8b43a307
Author: Miguel Angel Ajo <email address hidden>
Date: Mon Jan 5 12:34:53 2015 +0000

    Ensure config directory created before updating leases

    Under high load conditions dhcp-agent could try to start the
    dhcp local process via reload_allocations. But it will fail since
    the dhcp config directory for the specific network is not
    created yet.

    We ensure its creation with this patch.

    Closes-Bug: 1407618

    Change-Id: Ib37651f7f802debd472ab292b148c2a2496063a3