add uemgr pkg

pkg/uemgr/manager.go

@@ -1,16 +1,169 @@
 package uemgr
 
-// TODO
-func NewManager() {
+import (
+	"context"
+	"io"
+	"strconv"
 
+	"github.com/onosproject/onos-api/go/onos/uenib"
+	"github.com/onosproject/onos-lib-go/pkg/grpc/retry"
+	"github.com/onosproject/onos-lib-go/pkg/logging"
+	"github.com/onosproject/onos-ric-sdk-go/pkg/e2/creds"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+)
+
+var log = logging.GetLogger("qmai", "uemgr")
+
+// creates a new UE Manager
+func NewManager(config Config) (Manager, error) {
+	// onos-uenib address
+	ueNibServiceAddress := config.UeNibEndpoint + ":" + strconv.Itoa(config.UeNibPort)
+	// connects to UE NIB service
+	conn, err := connectUeNibServiceHost(ueNibServiceAddress)
+	if err != nil {
+		return Manager{}, err
+	}
+	// creates a ue-nib client
+	ueClient := uenib.CreateUEServiceClient(conn)
+
+	return Manager{
+		ueClient: ueClient,
+	}, nil
+}
+
+// starts UE Manager
+func (m *Manager) Start() error {
+	// go routine
+	go func() {
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		err := m.watchUEConnections(ctx)
+		if err != nil {
+			log.Warn(err)
+			return
+		}
+	}()
+
+	return nil
 }
 
-// TODO
-func start() error {
+// watch UEs changes
+func (m *Manager) watchUEConnections(ctx context.Context) error {
+	// list UEs
+	m.listUEs(ctx)
+
+	// watch changes
+	log.Info("Starting to watch the UEs changes")
+	stream, err := m.ueClient.WatchUEs(ctx, &uenib.WatchUERequest{AspectTypes: defaultAspectTypes})
+	if err != nil {
+		log.Warn(err)
+		return err
+	}
+
+	for {
+		msg, err := stream.Recv()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			log.Warn(err)
+		}
+
+		log.Debug(msg.Event.Type.String(), msg.Event.UE.String())
+		// processEvent(); (TODO)
+	}
+
 	return nil
 }
 
-// TODO
-func listUEs() {
+// list all UEs
+func (m *Manager) listUEs(ctx context.Context) {
+	log.Info("Starting UEs listing")
+	// get UEs stream
+	stream, err := m.ueClient.ListUEs(ctx, &uenib.ListUERequest{AspectTypes: defaultAspectTypes})
+	if err != nil {
+		log.Warn(err)
+		return
+	}
+
+	// Number of UEs
+	num_ues := 0
+
+	for {
+		response, err := stream.Recv()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			log.Warn(err)
+		}
+
+		// increment num of UEs
+		num_ues++
+
+		// print UE num and UE ID
+		log.Debugf("UE-%d with ID %v connected", num_ues, response.UE.ID)
+
+		// get UE aspectTypes
+		aspects := m.getUEAspects(ctx, response.UE.ID)
+		log.Debugf("Available aspects of UE-%d: %s", num_ues, aspects)
+	}
+
+	log.Infof("Total connected UEs: %d", num_ues)
+}
+
+// func (m *Manager) getUes() (uenib.UE, error) { // TODO
+// }
+
+// getUE gets UE aspects
+func (m *Manager) getUEAspects(ctx context.Context, ueID uenib.ID) []string {
+	response, err := m.ueClient.GetUE(ctx, &uenib.GetUERequest{ID: ueID})
+	if err != nil {
+		log.Warn(err)
+		return nil
+	}
+
+	var aspects []string
+
+	for k := range response.UE.GetAspects() {
+		aspects = append(aspects, k)
+	}
+
+	return aspects
+}
+
+func (m *Manager) createUEAspect(ctx context.Context) {
+}
+
+// TODO: it is not necessary for now
+func (m *Manager) updateUEAspects(ctx context.Context, ue uenib.UE) {
+	log.Debug("Updating UE aspects")
+
+	// uncomment me to set aspect to existing UE
+	// ue.SetAspect(&uenib.CellInfo{ServingCell: &uenib.CellConnection{
+	// 	ID:             "e2:4/e00/2/64/e0000",
+	// 	SignalStrength: 11.0,
+	// }})
+
+	_, err := m.ueClient.UpdateUE(ctx, &uenib.UpdateUERequest{
+		UE: ue,
+	})
+
+	if err != nil {
+		log.Warn(err)
+	}
+}
 
+// ConnectUeNibServiceHost connects to UE NIB service
+func connectUeNibServiceHost(UeNibServiceAddress string) (*grpc.ClientConn, error) {
+	tlsConfig, err := creds.GetClientCredentials()
+	if err != nil {
+		return nil, err
+	}
+	opts := []grpc.DialOption{
+		grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)),
+	}
+	opts = append(opts, grpc.WithUnaryInterceptor(retry.RetryingUnaryClientInterceptor()))
+	return grpc.DialContext(context.Background(), UeNibServiceAddress, opts...)
 }

pkg/uemgr/options.go

@@ -1 +1,22 @@
 package uemgr
+
+import "github.com/onosproject/onos-api/go/onos/uenib"
+
+// default aspect types to get of UEs
+var defaultAspectTypes = []string{}
+
+type Manager struct {
+	ueClient uenib.UEServiceClient
+}
+
+type Config struct {
+	UeNibEndpoint string
+	UeNibPort     int
+}
+
+type UE struct {
+	ID          string
+	aspectTypes []string
+}
+
+type UEs []UE