dnsmasq dhcp lease is not cleaned up after instance termination
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
kolla |
New
|
Undecided
|
Unassigned |
Bug Description
On a kolla 3.0.1 AiO deployment inside a Fedora 25 VM (packages updated) spawning new instances fails because tenant network DHCP leases are not getting cleaned up in dnsmasq.
How to reproduce:
- Install Kolla AiO according to Quick Start Guide using most current container binary images for CentOS or Ubuntu
- Deploy minimum OpenStack Admin infrastruture (Provider network, image, flavor)
- Spawn a tenant VM instance in a tenant network
- watch the DHCP lease for the instance get created in /var/lib/
- delete instance
- watch the dhcp_release call being placed correctly in neutron-dhcp-agent log with debug enabled:
2017-01-12 01:26:33.769 7 DEBUG neutron.
command: ['sudo', 'neutron-rootwrap', '/etc/neutron/
Expected behavior:
- lease is removed from dnsmasq lease file upon instance deletion
Actual behavior:
- lease is not removed from dnsmasq lease file
- further instances may not get IP addresses from dnsmasq because it's still hold by the orphaned lease, instance therefore do not spawn correctly because without IP they cannot get metadata
- observe log messages in dnsmasq hinting the root cause:
Jan 12 01:40:58 dnsmasq-dhcp[701]: not using configured address 172.16.0.3 because it is leased to fa:16:3e:12:50:3c
- with tcpdump on the dnsmasq tap interface no DHCP_RELEASE packet can be seen during dhcp_release call in neutron
Addendum: the behavior cannot be reproduced with either type of binary image when deployed on a VM running CentOS 7.3.1611