Removing ExternalIP Fails to Withdraw Route

[ghost]

I am using externalIPs to advertise out anycast BGP routes from kube-router. Advertising works as you'd expect: I add an externalIP and it is advertised. Unfortunately when removing the externalIP, the route is never withdrawn from my peers.

Running kube-router version v0.2.0-beta.7, built on 2018-06-08T09:34:34+0000, go1.8.7

[ghost]

@murali-reddy If you can provide a bit of insight into which package this bug likely exists in, I will start hunting for it.

[murali-reddy]

@MagikMan please see

https://github.com/cloudnativelabs/kube-router/blob/master/pkg/controllers/routing/ecmp_vip.go

this is where all service VIP's that are to be advertised and withdrawn are identified

[mk01]

@MagikMan @murali-reddy

it is because the on update() methods are not considering previous state.
in this PR 669 is implemented one way to fix (by remembering currently advertised list of ext ip)

another way would be to pass oldObj on update too and take the previous list from there. perhaps it would be even better.

(update: created #670 as the second variant and closed 669)

mk