1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
/*
*
* 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 server is an example server.
package main
import (
"context"
"flag"
"fmt"
"log"
"net"
"time"
"google.golang.org/grpc"
pb "google.golang.org/grpc/examples/features/proto/echo"
"google.golang.org/grpc/health"
healthpb "google.golang.org/grpc/health/grpc_health_v1"
)
var (
port = flag.Int("port", 50051, "the port to serve on")
sleep = flag.Duration("sleep", time.Second*5, "duration between changes in health")
system = "" // empty string represents the health of the system
)
type echoServer struct {
pb.UnimplementedEchoServer
}
func (e *echoServer) UnaryEcho(ctx context.Context, req *pb.EchoRequest) (*pb.EchoResponse, error) {
return &pb.EchoResponse{
Message: fmt.Sprintf("hello from localhost:%d", *port),
}, nil
}
var _ pb.EchoServer = &echoServer{}
func main() {
flag.Parse()
lis, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
s := grpc.NewServer()
healthcheck := health.NewServer()
healthpb.RegisterHealthServer(s, healthcheck)
pb.RegisterEchoServer(s, &echoServer{})
go func() {
// asynchronously inspect dependencies and toggle serving status as needed
next := healthpb.HealthCheckResponse_SERVING
for {
healthcheck.SetServingStatus(system, next)
if next == healthpb.HealthCheckResponse_SERVING {
next = healthpb.HealthCheckResponse_NOT_SERVING
} else {
next = healthpb.HealthCheckResponse_SERVING
}
time.Sleep(*sleep)
}
}()
if err := s.Serve(lis); err != nil {
log.Fatalf("failed to serve: %v", err)
}
}
|
