addressing the latest comments

cns/cnireconciler/podinfoprovider.go

@@ -54,7 +54,7 @@ func newCNIPodInfoProvider(exc exec.Interface, stateMigration bool) (cns.PodInfo
 	}
 	var endpointState map[string]*restserver.EndpointInfo
 	if stateMigration {
-		endpointState, err = cniStateToCnsEndpointState(state)
+		endpointState = cniStateToCnsEndpointState(state)
 	} else {
 		endpointState = nil
 	}
@@ -117,7 +117,7 @@ func endpointStateToPodInfoByIP(state map[string]*restserver.EndpointInfo) (map[
 // cniStateToCnsEndpointState converts an AzureCNIState dumped from a CNI exec
 // into a EndpointInfo map, using the containerID as keys in the map.
 // The map then will be saved on CNS endpoint state
-func cniStateToCnsEndpointState(state *api.AzureCNIState) (map[string]*restserver.EndpointInfo, error) {
+func cniStateToCnsEndpointState(state *api.AzureCNIState) map[string]*restserver.EndpointInfo {
 	logger.Printf("Generating CNS Endpoint State")
 	endpointState := map[string]*restserver.EndpointInfo{}
 	for epID, endpoint := range state.ContainerInterfaces {
@@ -126,22 +126,10 @@ func cniStateToCnsEndpointState(state *api.AzureCNIState) (map[string]*restserve
 		for _, epIP := range endpoint.IPAddresses {
 			if epIP.IP.To4() == nil { // is an ipv6 address
 				ipconfig := net.IPNet{IP: epIP.IP, Mask: epIP.Mask}
-				for _, ipconf := range ipInfo.IPv6 {
-					if ipconf.IP.Equal(ipconfig.IP) {
-						logger.Errorf("Found existing ipv6 ipconfig for infra container %s", endpoint.ContainerID)
-						return nil, restserver.ErrExistingIpconfigFound
-					}
-				}
 				ipInfo.IPv6 = append(ipInfo.IPv6, ipconfig)
 
 			} else {
 				ipconfig := net.IPNet{IP: epIP.IP, Mask: epIP.Mask}
-				for _, ipconf := range ipInfo.IPv4 {
-					if ipconf.IP.Equal(ipconfig.IP) {
-						logger.Errorf("Found existing ipv4 ipconfig for infra container %s", endpoint.ContainerID)
-						return nil, restserver.ErrExistingIpconfigFound
-					}
-				}
 				ipInfo.IPv4 = append(ipInfo.IPv4, ipconfig)
 			}
 		}
@@ -150,7 +138,7 @@ func cniStateToCnsEndpointState(state *api.AzureCNIState) (map[string]*restserve
 		endpointState[endpointID] = endpointInfo
 		logger.Printf("CNS endpoint state extracted from CNI: [%+v]", *endpointInfo)
 	}
-	return endpointState, nil
+	return endpointState
 }
 
 // extractEndpointInfo extract Interface Name and endpointID for each endpoint based the CNI state

cns/configuration/configuration.go

@@ -56,7 +56,7 @@ type CNSConfig struct {
 	UseHTTPS                    bool
 	WatchPods                   bool `json:"-"`
 	WireserverIP                string
-	StatelessCNIMigration       bool
+	StateMigration              bool
 }
 
 type TelemetrySettings struct {

cns/restserver/ipam.go

@@ -27,7 +27,6 @@ var (
 	ErrNoNCs                  = errors.New("no NCs found in the CNS internal state")
 	ErrOptManageEndpointState = errors.New("CNS is not set to manage the endpoint state")
 	ErrEndpointStateNotFound  = errors.New("endpoint state could not be found in the statefile")
-	ErrExistingIpconfigFound  = errors.New("Found existing ipconfig for infra container")
 )
 
 const (
@@ -1074,6 +1073,9 @@ func (service *HTTPRestService) GetEndpointHelper(endpointID string) (*EndpointI
 		logger.Warnf("[GetEndpointState] Found existing endpoint state for container %s", endpointID)
 		return endpointInfo, nil
 	}
+	// This part is a temprory fix if we have endpoint states belong to CNI version 1.4.X on Windows since the states don't have the containerID
+	// In case there was no endpoint founded with ContainerID as the key,
+	// then [First 8 character of containerid]-eth0 will be tried
 	legacyEndpointID := endpointID[:ContainerIDLength] + "-" + InterfaceName
 	if endpointInfo, ok := service.EndpointState[legacyEndpointID]; ok {
 		logger.Warnf("[GetEndpointState] Found existing endpoint state for container %s", legacyEndpointID)

cns/service/main.go

@@ -1521,11 +1521,11 @@ func InitializeStateFromCNS(cnsconfig *configuration.CNSConfig, endpointStateSto
 	if err != nil {
 		if errors.Is(err, store.ErrKeyNotFound) {
 			logger.Printf("[Azure CNS] No endpoint state found, skipping initializing CNS state")
-			if cnsconfig.StatelessCNIMigration {
+			if cnsconfig.StateMigration {
 				logger.Printf("StatelessCNI Migration is enabled")
 				logger.Printf("initializing from Statefull CNI")
 				var endpointState map[string]*restserver.EndpointInfo
-				podInfoByIPProvider, endpointState, err = cnireconciler.NewCNIPodInfoProvider(cnsconfig.StatelessCNIMigration)
+				podInfoByIPProvider, endpointState, err = cnireconciler.NewCNIPodInfoProvider(cnsconfig.StateMigration)
 				if err != nil {
 					return nil, errors.Wrap(err, "failed to create CNI PodInfoProvider")
 				}