Kube-router: Garbage collect KUBE_DUMMY_IF ip assignments

[johanot]

Deleted or changed service IP's are not removed from the KUBE_DUMMY_IF on nodes.

We currently have about 70 active ClusterIP services in our cluster, but kube-dummy-if has 1059 ip-addresses assigned. This actually turned out to be a real problem, because we had another host service that was configured to listen on all interfaces and breached ulimits when trying to open its 1024+ listening socket.

Since no auto-cleanup is running and we don't want to restart kube-router with --cleanup every night or so, I believe it should be a reconciliation step to delete unused serviceIP's from the dummy interface, just like unused ipvs rules are purged today.

[murali-reddy]

@johanot thanks for reporting. Yes this must be fixed. I will work on a fix.

[killcity]

Is this the same as https://github.com/cloudnativelabs/kube-router/issues/383?

[murali-reddy]

@killcity no #383 is different issue. This issue relates to internal implementation detail of kube-router.

[murali-reddy]

If any one like to verify the fix in #417 please use cloudnativelabs/kube-router-git:master image.

[johanot]

@murali-reddy Works like a charm! Just tested - during today's keynote in Copenhagen :-) - on our cluster and stale IP's are removed as expected.

[murali-reddy]

@johanot thanks for confirming.

@dlamotte Keep the PR's coming in :)

[murali-reddy]

Just tested - during today's keynote in Copenhagen :-)

@johanot do plan to attend https://kccnceu18.sched.com/event/Dqv8/global-container-networks-on-kubernetes-at-digitalocean-andrew-sy-kim-digitalocean-intermediate-skill-level :)