[tempest] No metadata route in test_dualnet* family

Bug #1544515 reported by Evgeny Antyshev
This bug affects 3 people
Affects Status Importance Assigned to Milestone

Bug Description

We run tempest in such an environment that all ssh keys, personality files, etc. go through metadata service.
Which requires metadata route to being provided by DHCP.

We faced rather complicated problem in scenario/test_network_v6.py:

Networking configuration comprises of 4 steps:
1) Private network creation
2) Router creation and plugging it as a gateway in external network
3) Subnet creation
4) Adding router interface to the subnet

This sequence leads to that DHCP service provides static metadata route, and our scenario works.
That's how it is done in create_networks() from tempest/scenario/manager.py (which used in the majority of tests).

But, prepare_network() of scenario/test_network_v6.py first creates subnet, and after that it creates router (1-3-2-4).
DHCP service configuration in neutron regards this subnet isolated then (which is what I don't understand), therefore,
doesn't provide it with metadata route by default (force_metadata=False, enable_isolated_metadata=False).

It really seems like Neutron has a bug handling such scenario: it doesn't update DHCP service configuration when router is created for subnet.

Also, AFAIU, all the upstream Jenkins dsvm tempest jobs running test_dualnet* get metadata from config drive,
 that's possibly why they aren't affected.

Revision history for this message
Ihar Hrachyshka (ihar-hrachyshka) wrote :

Confirming. Once you kill dnsmasq and DHCP agent, and restart the agent, new configuration files are generated for the network that serve proper static routes pointing to router IP.

Changed in neutron:
status: New → Confirmed
tags: added: l3-ipam-dhcp
Changed in neutron:
importance: Undecided → High
Revision history for this message
Mark Rawlings (mark-rawlings) wrote :

Simply because this appears to be happening on what would be the transition from a network appearing to be isolated, to it appearing to be non-isolated. Is there a potential relationship here to Bug: #1450548 ? That issue indicates issues for VMs caught in the transitions between isolation states.

Is a symptom that 'some' VM's created before 4 in you second sequence do not receive metadata, but VMs created after 4 do?
(I accept that I'm looking for more examples of the other issue and I'll back away peacefully if I'm off base.)

Revision history for this message
Evgeny Antyshev (eantyshev) wrote :

Strictly speaking, your last question has no answer: I was describing how networking is created, and it doesn't matter when VMs are connected (since it AFAIU doesn't trigger dhcp server reconfiguration).

But the above bug is about the same problem: detection of whether subnet is isolated is or not is done in unreliable fashion.

Changed in neutron:
assignee: nobody → Mohammed Ashraf (mohammed-asharaf)
Changed in neutron:
status: Confirmed → In Progress
Changed in neutron:
assignee: Mohammed Ashraf (mohammed-asharaf) → nobody
Changed in neutron:
status: In Progress → Incomplete
importance: High → Undecided
Revision history for this message
Launchpad Janitor (janitor) wrote :

[Expired for neutron because there has been no activity for 60 days.]

Changed in neutron:
status: Incomplete → Expired
To post a comment you must log in.
This report contains Public information  
Everyone can see this information.

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.