Bug 2107515

Summary:	[RFE] Add information at NB DB about where gateway chassis port are bound
Product:	Red Hat Enterprise Linux Fast Datapath	Reporter:	Luis Tomas Bolivar <ltomasbo>
Component:	OVN	Assignee:	Lucas Alvares Gomes <lmartins>
Status:	ASSIGNED ---	QA Contact:	ying xu <yinxu>
Severity:	unspecified	Docs Contact:
Priority:	medium
Version:	FDP 21.K	CC:	amusil, ctrautma, jiji, jishi, lmartins, mmichels
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Bug Blocks:	2193095

Description Luis Tomas Bolivar 2022-07-15 10:41:14 UTC

In order to expose OVN LoadBalancers at OpenStack with BGP the traffic needs to be exposed on the chassis having the CR-LRP port. As this information is only available currently at the OVN SB DB, the ovn-bgp-agent [1] is connected to it. This forces making some assumptions about OVN SB DBs that may change in the future (such as the availability of a Load_Balancer table).

In order not to double the number of connections to OVN DBs (i.e., SB + NB), it would be required to add the gateway chassis binding information to the NB. This would enable only connecting to NB to expose the routes though BGP.


[1] https://opendev.org/x/ovn-bgp-agent

Comment 1 Mark Michelson 2022-07-21 19:10:09 UTC

Hi Luis, I'm triaging this issue. I'm having trouble understanding which information you need in the northbound database. Can you be more specific about what you currently are getting from the southbound database and where in the northbound database you would like it to live? Is the issue that you have set multiple gateway chassis for a router port and you need to know which of the configured chassis the port is currently bound on? Or have I misinterpreted the request?

Thanks!

Comment 2 Luis Tomas Bolivar 2022-07-22 07:18:03 UTC

Hi Mark, that is exactly what I need. For instance, https://opendev.org/x/ovn-bgp-agent is using this information to be able to expose ovn-lb through BGP (as the ARP reply comes from the cr-lrp port where the loadbalancer members are connected through) on the node currently holding the gateway chassis port. This information is available at SB DB, but not at NB DB. For what I saw, that is the only information I'm missing so that we could change the agent to use NB instead of SB.

Comment 3 Mark Michelson 2022-07-22 17:36:05 UTC

Thanks, Luis. I'll mark triage complete.