| /* |
| * |
| * Copyright 2020 gRPC authors. |
| * |
| * 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. |
| * |
| */ |
| |
| // Binary client is an example client. |
| package main |
| |
| import ( |
| "context" |
| "flag" |
| "fmt" |
| "log" |
| "time" |
| |
| "google.golang.org/grpc" |
| pb "google.golang.org/grpc/examples/features/proto/echo" |
| _ "google.golang.org/grpc/health" |
| "google.golang.org/grpc/resolver" |
| "google.golang.org/grpc/resolver/manual" |
| ) |
| |
| var serviceConfig = `{ |
| "loadBalancingPolicy": "round_robin", |
| "healthCheckConfig": { |
| "serviceName": "" |
| } |
| }` |
| |
| func callUnaryEcho(c pb.EchoClient) { |
| ctx, cancel := context.WithTimeout(context.Background(), time.Second) |
| defer cancel() |
| r, err := c.UnaryEcho(ctx, &pb.EchoRequest{}) |
| if err != nil { |
| fmt.Println("UnaryEcho: _, ", err) |
| } else { |
| fmt.Println("UnaryEcho: ", r.GetMessage()) |
| } |
| } |
| |
| func main() { |
| flag.Parse() |
| |
| r := manual.NewBuilderWithScheme("whatever") |
| r.InitialState(resolver.State{ |
| Addresses: []resolver.Address{ |
| {Addr: "localhost:50051"}, |
| {Addr: "localhost:50052"}, |
| }, |
| }) |
| |
| address := fmt.Sprintf("%s:///unused", r.Scheme()) |
| |
| options := []grpc.DialOption{ |
| grpc.WithInsecure(), |
| grpc.WithBlock(), |
| grpc.WithResolvers(r), |
| grpc.WithDefaultServiceConfig(serviceConfig), |
| } |
| |
| conn, err := grpc.Dial(address, options...) |
| if err != nil { |
| log.Fatalf("did not connect %v", err) |
| } |
| defer conn.Close() |
| |
| echoClient := pb.NewEchoClient(conn) |
| |
| for { |
| callUnaryEcho(echoClient) |
| time.Sleep(time.Second) |
| } |
| } |