Split CNI into watcher/handler under felix

This patch splits the CNI watcher and handlers
in two pieces. The handling will be done in the main
'felix' goroutine, while the watching / grpc server
will live under watchers/ and not store or access agent
state.

The intent is to move away from a model with multiple servers
replicating state and communicating over a pubsub. This being
prone to race conditions, deadlocks, and not providing many
benefits as scale & asynchronicity will not be a constraint
on nodes with relatively small number of pods (~100) as is k8s
default.

Signed-off-by: Nathan Skrzypczak <[email protected]>

Author: sknat

calico-vpp-agent/cmd/calico_vpp_dataplane.go

@@ -34,7 +34,6 @@ import (
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 
-	"github.com/projectcalico/vpp-dataplane/v3/calico-vpp-agent/cni"
 	"github.com/projectcalico/vpp-dataplane/v3/calico-vpp-agent/common"
 	"github.com/projectcalico/vpp-dataplane/v3/calico-vpp-agent/connectivity"
 	"github.com/projectcalico/vpp-dataplane/v3/calico-vpp-agent/felix"
@@ -144,12 +143,12 @@ func main() {
 	localSIDWatcher := watchers.NewLocalSIDWatcher(vpp, clientv3, log.WithFields(logrus.Fields{"subcomponent": "localsid-watcher"}))
 	felixServer := felix.NewFelixServer(vpp, clientv3, log.WithFields(logrus.Fields{"component": "policy"}))
 	felixWatcher := watchers.NewFelixWatcher(felixServer.GetFelixServerEventChan(), log.WithFields(logrus.Fields{"component": "felix watcher"}))
+	cniServer := watchers.NewCNIServer(felixServer.GetFelixServerEventChan(), log.WithFields(logrus.Fields{"component": "cni"}))
 	err = watchers.InstallFelixPlugin()
 	if err != nil {
 		log.Fatalf("could not install felix plugin: %s", err)
 	}
 	connectivityServer := connectivity.NewConnectivityServer(vpp, felixServer, clientv3, log.WithFields(logrus.Fields{"subcomponent": "connectivity"}))
-	cniServer := cni.NewCNIServer(vpp, felixServer, log.WithFields(logrus.Fields{"component": "cni"}))
 
 	/* Pubsub should now be registered */
 
@@ -184,7 +183,6 @@ func main() {
 		serviceServer.SetOurBGPSpec(bgpSpec)
 		localSIDWatcher.SetOurBGPSpec(bgpSpec)
 		netWatcher.SetOurBGPSpec(bgpSpec)
-		cniServer.SetOurBGPSpec(bgpSpec)
 	}
 
 	if *config.GetCalicoVppFeatureGates().MultinetEnabled {
@@ -197,7 +195,6 @@ func main() {
 		if !ok {
 			panic("ourBGPSpec is not *felixconfig.Config")
 		}
-		cniServer.SetFelixConfig(felixCfg)
 		connectivityServer.SetFelixConfig(felixCfg)
 	}