VOL-1967 move api-server to separate repository

Current with voltha-go acf0adaf2d91ae72b55192cc8a939e0485918d16

Change-Id: I000ea6be0789e20c922bd671562b58a7120892ae
diff --git a/internal/pkg/afrouter/round-robin-router.go b/internal/pkg/afrouter/round-robin-router.go
new file mode 100644
index 0000000..b5f031e
--- /dev/null
+++ b/internal/pkg/afrouter/round-robin-router.go
@@ -0,0 +1,125 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package afrouter
+
+import (
+	"errors"
+	"fmt"
+	"github.com/opencord/voltha-go/common/log"
+	"google.golang.org/grpc"
+)
+
+type RoundRobinRouter struct {
+	name           string
+	grpcService    string
+	cluster        *cluster
+	currentBackend **backend
+}
+
+func newRoundRobinRouter(rconf *RouterConfig, config *RouteConfig) (Router, error) {
+	var err error = nil
+	var rtrn_err = false
+	// Validate the configuration
+
+	log.Debug("Creating a new round robin router")
+	// A name must exist
+	if config.Name == "" {
+		log.Error("A router 'name' must be specified")
+		rtrn_err = true
+	}
+
+	if rconf.ProtoPackage == "" {
+		log.Error("A 'package' must be specified")
+		rtrn_err = true
+	}
+
+	if rconf.ProtoService == "" {
+		log.Error("A 'service' must be specified")
+		rtrn_err = true
+	}
+
+	var bptr *backend
+	bptr = nil
+	rr := RoundRobinRouter{
+		name:           config.Name,
+		grpcService:    rconf.ProtoService,
+		currentBackend: &bptr,
+	}
+
+	// Create the backend cluster or link to an existing one
+	ok := true
+	if rr.cluster, ok = clusters[config.backendCluster.Name]; !ok {
+		if rr.cluster, err = newBackendCluster(config.backendCluster); err != nil {
+			log.Errorf("Could not create a backend for router %s", config.Name)
+			rtrn_err = true
+		}
+	}
+
+	if rtrn_err {
+		return rr, errors.New(fmt.Sprintf("Failed to create a new router '%s'", rr.name))
+	}
+
+	return rr, nil
+}
+
+func (rr RoundRobinRouter) GetMetaKeyVal(serverStream grpc.ServerStream) (string, string, error) {
+	return "", "", nil
+}
+
+func (rr RoundRobinRouter) IsStreaming(_ string) (bool, bool) {
+	panic("not implemented")
+}
+
+func (rr RoundRobinRouter) BackendCluster(s string, mk string) (*cluster, error) {
+	return rr.cluster, nil
+}
+
+func (rr RoundRobinRouter) Name() string {
+	return rr.name
+}
+
+func (rr RoundRobinRouter) Route(sel interface{}) (*backend, *connection) {
+	var err error
+	switch sl := sel.(type) {
+	case *requestFrame:
+		// Since this is a round robin router just get the next backend
+		if *rr.currentBackend, err = rr.cluster.nextBackend(*rr.currentBackend, BackendSequenceRoundRobin); err == nil {
+			return *rr.currentBackend, nil
+		} else {
+			sl.err = err
+			return nil, nil
+		}
+	default:
+		log.Errorf("Internal: invalid data type in Route call %v", sel)
+		return nil, nil
+	}
+}
+
+func (rr RoundRobinRouter) Service() string {
+	return rr.grpcService
+}
+
+func (rr RoundRobinRouter) FindBackendCluster(becName string) *cluster {
+	if becName == rr.cluster.name {
+		return rr.cluster
+	}
+	return nil
+}
+
+func (rr RoundRobinRouter) ReplyHandler(sel interface{}) error { // This is a no-op
+	return nil
+}