Added core_pair_topic flag.  Removed UpdateMembership and GetMembership calls.

This flag must also be added to the helm charts to work correctly.

VOL-1828

Change-Id: Id992c31b04e54468a94cb5bebcb779600f592ecf
diff --git a/rw_core/core/core.go b/rw_core/core/core.go
index 224b3cb..d82119c 100644
--- a/rw_core/core/core.go
+++ b/rw_core/core/core.go
@@ -17,8 +17,6 @@
 
 import (
 	"context"
-	"errors"
-	"fmt"
 	grpcserver "github.com/opencord/voltha-go/common/grpc"
 	"github.com/opencord/voltha-go/common/log"
 	"github.com/opencord/voltha-go/db/kvstore"
@@ -27,9 +25,6 @@
 	"github.com/opencord/voltha-go/rw_core/config"
 	"github.com/opencord/voltha-protos/go/voltha"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
-	"sync"
 )
 
 type Core struct {
@@ -48,8 +43,6 @@
 	exitChannel       chan int
 	kvClient          kvstore.Client
 	kafkaClient       kafka.Client
-	coreMembership    *voltha.Membership
-	membershipLock    sync.RWMutex
 	deviceOwnership   *DeviceOwnership
 }
 
@@ -179,53 +172,16 @@
 		return err
 	}
 
+	// Register the core-pair topic to handle core-bound requests destined to the core pair
+	if err := core.kmp.SubscribeWithDefaultRequestHandler(kafka.Topic{Name: core.config.CorePairTopic}, kafka.OffsetNewest); err != nil {
+		log.Fatalw("Failed-registering-pair-handler", log.Fields{"topic": core.config.CorePairTopic})
+		return err
+	}
+
 	log.Info("request-handler-registered")
 	return nil
 }
 
-func (core *Core) isMembershipRegistrationComplete() bool {
-	core.membershipLock.RLock()
-	defer core.membershipLock.RUnlock()
-	return core.coreMembership != nil
-}
-
-func (core *Core) updateCoreMembership(ctx context.Context, membership *voltha.Membership) error {
-	core.membershipLock.Lock()
-	defer core.membershipLock.Unlock()
-	// Sanity check - can only register once
-	if core.coreMembership != nil {
-		log.Warnw("core-reregistration-not-allowed", log.Fields{"membership": membership})
-		return status.Errorf(codes.AlreadyExists, "%s", membership.GroupName)
-	}
-
-	if membership == nil || membership.GroupName == "" {
-		return errors.New("invalid-membership-info")
-	}
-
-	core.coreMembership = membership
-
-	// Use the group name to register a specific kafka topic for this container
-	go func(groupName string) {
-		// Register the core-pair topic to handle core-bound requests destined to the core pair
-		pTopic := kafka.Topic{Name: fmt.Sprintf("%s_%s", core.config.CoreTopic, groupName)}
-		// TODO: Set a retry here to ensure this subscription happens
-		if err := core.kmp.SubscribeWithDefaultRequestHandler(pTopic, kafka.OffsetNewest); err != nil {
-			log.Fatalw("Failed-registering-pair-handler", log.Fields{"topic": core.config.CoreTopic})
-		}
-		// Update the CoreTopic to be used by the adapter proxy
-		core.deviceMgr.adapterProxy.updateCoreTopic(&pTopic)
-	}(membership.GroupName)
-
-	log.Info("core-membership-registered")
-	return nil
-}
-
-func (core *Core) getCoreMembership(ctx context.Context) *voltha.Membership {
-	core.membershipLock.RLock()
-	defer core.membershipLock.RUnlock()
-	return core.coreMembership
-}
-
 func (core *Core) startDeviceManager(ctx context.Context) {
 	log.Info("DeviceManager-Starting...")
 	core.deviceMgr.start(ctx, core.logicalDeviceMgr)