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
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
/*
*
* 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.
*
*/
// Package main starts Greeter service that will response with the hostname.
package main
import (
"context"
"flag"
"fmt"
"log"
"math/rand"
"net"
"os"
"strconv"
"time"
"google.golang.org/grpc"
pb "google.golang.org/grpc/examples/helloworld/helloworld"
"google.golang.org/grpc/health"
healthpb "google.golang.org/grpc/health/grpc_health_v1"
"google.golang.org/grpc/reflection"
)
var help = flag.Bool("help", false, "Print usage information")
const (
defaultPort = 50051
)
// server is used to implement helloworld.GreeterServer.
type server struct {
pb.UnimplementedGreeterServer
serverName string
}
func newServer(serverName string) *server {
return &server{
serverName: serverName,
}
}
// SayHello implements helloworld.GreeterServer
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
log.Printf("Received: %v", in.GetName())
return &pb.HelloReply{Message: "Hello " + in.GetName() + ", from " + s.serverName}, nil
}
func determineHostname() string {
hostname, err := os.Hostname()
if err != nil {
log.Printf("Failed to get hostname: %v, will generate one", err)
rand.Seed(time.Now().UnixNano())
return fmt.Sprintf("generated-%03d", rand.Int()%100)
}
return hostname
}
func init() {
flag.Usage = func() {
fmt.Fprintf(flag.CommandLine.Output(), `
Usage: server [port [hostname]]
port
The listen port. Defaults to %d
hostname
The name clients will see in greet responses. Defaults to the machine's hostname
`, defaultPort)
flag.PrintDefaults()
}
}
func main() {
flag.Parse()
if *help {
flag.Usage()
return
}
args := flag.Args()
if len(args) > 2 {
flag.Usage()
return
}
port := defaultPort
if len(args) > 0 {
var err error
port, err = strconv.Atoi(args[0])
if err != nil {
log.Printf("Invalid port number: %v", err)
flag.Usage()
return
}
}
var hostname string
if len(args) > 1 {
hostname = args[1]
}
if hostname == "" {
hostname = determineHostname()
}
lis, err := net.Listen("tcp", fmt.Sprintf("localhost:%d", port))
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
s := grpc.NewServer()
pb.RegisterGreeterServer(s, newServer(hostname))
reflection.Register(s)
healthServer := health.NewServer()
healthServer.SetServingStatus("", healthpb.HealthCheckResponse_SERVING)
healthpb.RegisterHealthServer(s, healthServer)
log.Printf("serving on %s, hostname %s", lis.Addr(), hostname)
s.Serve(lis)
}
|
