Is Contiv-vpp supported as a secondary plugin in Multus

[dushyantbehl]

My requirement is to setup Contiv on a network running Multus+Flannel with some nodes running Contiv/VPP. This is an updated version of the issue(#1739).

Here's what I have done so far -

1. Bare K8 cluster running Multus + Flannel
2. Apply contiv-vpp.yaml
3. Created a crd with contiv-cni as Network Attachment Definition -

apiVersion: "k8s.cni.cncf.io/v1"
kind: NetworkAttachmentDefinition
metadata:
  name: contiv-cni-test
spec:
  config: '{
    "cniVersion": "0.3.1",
    "type": "contiv-cni",
    "grpcServer": "/var/run/contiv/cni.sock",
    "logFile": "/var/run/contiv/cni.log"
  }'

4. Tried to create a Pod with the above network-attachment-definition in metadata as follows,

metadata:
  name: pod3
  annotations:
    k8s.v1.cni.cncf.io/networks: contiv-cni-test

After which contiv earlier threw an error, cannot create eth0 as the file exists

I manually modified the file plugins/ipnet/pod.go and changed the default podInterfaceHostName to eth1 as follows -

diff --git a/plugins/ipnet/pod.go b/plugins/ipnet/pod.go
index f6cd032..fa57034 100755
--- a/plugins/ipnet/pod.go
+++ b/plugins/ipnet/pod.go
@@ -46,7 +46,7 @@ const (
        podLinuxLoopLogicalNamePrefix = "linux-loop-"

        // interface host name as required by Kubernetes for every pod
-       podInterfaceHostName = "eth0" // required by Kubernetes
+       podInterfaceHostName = "eth1" // required by Kubernetes

        // prefix for logical name of AF-Packet interface (VPP) connecting a pod
        podAFPacketLogicalNamePrefix = "afpacket"

After recompiling contiv, I tested with updated docker images and got the following error -

Failed to create pod sandbox: rpc error: code = Unknown desc = failed to set up sandbox container "99dcc03daff59b936f3761ff2aa9d7be642e01c8fc3f98a224ea6653e66dedf2" network for pod "pod3": networkPlugin cni failed to set up pod "pod3_default" network: Multus: [default/pod3]: error adding container to network "contiv-cni-test": delegateAdd: error invoking DelegateAdd - "contiv-cni": error in getting result from AddNetwork: rpc error: code = Unknown desc = KeyErrors: [config/linux/l3/v2/route/0.0.0.0/0/linux-tap-99dcc03daff59b936f3761ff2aa9d7be642e01c8fc3f98a224ea6 (CREATE): failed to add linux route: file exists]

Note the failed to add linux route: file exists

What I wanna know before doing anything is that does Contiv support Multus and can act as a secondary plugin by changing some configuration? or is there any plan to extend support to Multus.

Thanks for any support.