devstack pre-created router doesn't work

[Maciej Jozefczyk]

Steps to reproduce:

1. spawn devstack master with ovn
2. set external gateway for pre-created port router1
3. LRP is not configured properly in provider net LS.
4. FIP doesn't work.

[Maciej Jozefczyk (maciejjozefczyk)]

There a missing LRP (gw chassis).

Is:

router 3ce77559-6530-4c73-a32d-e37de79b7350 (neutron-bc10e5fb-6193-4c52-b4db-6a31e5bac924) (aka router1)
    port lrp-862ea4c5-1c54-4fe6-a57d-1bb9879520c4
        mac: "fa:16:3e:46:be:3a"
        networks: ["10.0.0.1/26"]
    port lrp-a1effd17-1269-45ff-9d37-d5963c991cda
        mac: "fa:16:3e:2b:b0:e3"
        networks: ["fd95:72b0:b7bb::1/64"]
    nat 24ab65a1-c8c2-4598-b4df-718cfaa3ef29
        external ip: "172.24.4.150"
        logical ip: "10.0.0.0/26"
        type: "snat"
    nat 6a45737a-5943-4545-8a6a-41df6a6892e2
        external ip: "172.24.4.237"
        logical ip: "10.0.0.16"
        type: "dnat_and_snat"

Should be:
router 6c0b4118-51d5-4ac7-b962-05b055d4c9a6 (neutron-6b2d8fc5-bbdc-4b56-bf2b-eaef1cfe85f9) (aka router2)
    port lrp-e01cd375-3ad1-41c8-bfdf-79ef5eb86aee
        mac: "fa:16:3e:2d:47:6e"
        networks: ["172.24.4.86/24", "2001:db8::101/64"]
        gateway chassis: [6b381d97-540b-4729-aca6-8faa198bf1d6]
    port lrp-1ce05553-9beb-461c-a66e-a67681c7e237
        mac: "fa:16:3e:fe:9b:82"
        networks: ["10.10.10.1/24"]
    nat 16f3f00e-bde2-4d6d-9dcd-610ed9ff63c3
        external ip: "172.24.4.86"
        logical ip: "10.10.10.0/24"
        type: "snat"
    nat 24b855af-d7f5-41be-ba03-50c85a0b1ad6
        external ip: "172.24.4.20"
        logical ip: "10.10.10.103"
        type: "dnat_and_snat"

[Maciej Jozefczyk (maciejjozefczyk)]

From log perspective we can see that the port was bound:

2019-06-13T08:33:31.173Z|00011|binding|INFO|Claiming lport cr-lrp-cce2462f-ad6e-4b71-acf6-c9729a635558 for this chassis.
2019-06-13T08:33:31.173Z|00012|binding|INFO|cr-lrp-cce2462f-ad6e-4b71-acf6-c9729a635558: Claiming fa:16:3e:63:c0:2a 172.24.4.38/24

But after a while in neutron logs:

Jun 13 08:33:39 test-devstack-fail neutron-server[2525]: DEBUG ovsdbapp.backend.ovs_idl.transaction [-] Running txn n=1 command(idx=2): SetLRouterPortInLSwitchPortCommand(if_exists=True, lswitch_port=cce2462f-ad6e-4b71-acf6-c9729a635558, lrouter_port=lrp-cce2462f-ad6e-4b71-acf6-c9729a635558, is_gw_port=True, lsp_address=router) {{(pid=2726) do_commit /usr/local/lib/python2.7/dist-packages/ovsdbapp/backend/ovs_idl/transaction.py:84}}
Jun 13 08:33:39 test-devstack-fail neutron-server[2525]: DEBUG networking_ovn.ovsdb.ovsdb_monitor [-] Hash Ring: Node 916c4c20-4d40-48b1-bc4a-92bf789dc5f7 (host: test-devstack-fail) handling event "update" for row c5b8be61-623e-4615-abde-50923234389c (table: Logical_Switch_Port) {{(pid=2720) notify /opt/stack/networking-ovn/networking_ovn/ovsdb/ovsdb_monitor.py:368}}
Jun 13 08:33:39 test-devstack-fail neutron-server[2525]: WARNING networking_ovn.db.revision [None req-53a83310-cd8f-44a8-b587-ca18a95af337 None None] No revision row found for cce2462f-ad6e-4b71-acf6-c9729a635558 (type: router_ports) when bumping the revision number. Creating one.: NoResultFound: No row was found for one()
Jun 13 08:33:39 test-devstack-fail neutron-server[2525]: DEBUG networking_ovn.db.revision [None req-53a83310-cd8f-44a8-b587-ca18a95af337 None None] create_initial_revision uuid=cce2462f-ad6e-4b71-acf6-c9729a635558, type=router_ports, rev=-1 {{(pid=2726) create_initial_revision /opt/stack/networking-ovn/networking_ovn/db/revision.py:59}}

And the LRP is missing in the ovn-ndb:

stack@test-devstack-fail:~$ ovn-nbctl list logical_router_port lrp-cce2462f-ad6e-4b71-acf6-c9729a635558
ovn-nbctl: no row "lrp-cce2462f-ad6e-4b71-acf6-c9729a635558" in table Logical_Router_Port
stack@test-devstack-fail:~$

[Maciej Jozefczyk (maciejjozefczyk)]

Specific place in code where the condition is met that leads to remove of LRP:

https://github.com/openstack/networking-ovn/blob/d1e0fb482fecadf50318458f6cd040d257d4e55d/networking_ovn/common/ovn_client.py#L1028