[K8s-R5.0]: Pod in Isolated namespace cannot resolve DNS request

[Pulkit Tandon]

Kubernetes
R5.0 (Mainline)
Issue observed post CB build 85
Ocata
Ubuntu16.04

Setup:
HA setup with 3 Control nodes. 1 Kube master
2 compute nodes

Issue:
Created 1 Isolated namespaces:
root@testbed-1-vm1:~# kubectl describe namespace
Name: ctest-namespace-51821523
Labels: <none>
Annotations: opencontrail.org/isolation=true
Status: Active

Created 1 Pod in the isolated namespace
ctest-namespace-51821523 ctest-busybox-pod-14314702 1/1 Running 0 5m 10.47.255.251 testbed-1-vm2

Attempted to resolve DNS to kubernetes.default.svc.cluster.local
I was expecting it to resolve it correctly but it failed.
The issue has been introduced starting CB build 83.

On further debugging, found that the VN created on isolation of namespace does not have a route to DNS server 10.96.0.10.
There is no such route in VRF of the new VN corresponding to isolated namespace.

[Pulkit Tandon (pulkitt)]

Sanity test case that is failing due to this issue is :
TestServiceVNIsolated.test_kube_dns_lookup

[Yuvaraja Mariappan (ymariappan)]

https://review.opencontrail.org/#/c/38808/ will fix this as well.

Thanks,
Yuvaraja

[Pulkit Tandon (pulkitt)]

Verified on R5.0-ocata-103-ubuntu1604.
Issue is resolved. Hence closing the bug.