基于 Docker 的 pubsub 包实现的gRPC的发布与订阅

本文最后更新于:2 个月前

基于 Docker 的 pubsub 包实现的 gRPC 的发布与订阅

1. 创建对应的文件和目录

1
2
3
4
5
6
7
mkdir pubsub
cd pubsub
go mod init pubsub

mkdir proto publisher subscribe
touch server.go

2. 创建 proto 文件

1
2
cd proto
touch pubsub.proto
  • pubsub.proto 内容如下

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    syntax = "proto3";

    option go_package = "./;pb";

    message Result {
    string value = 1;
    }

    service PubSubService {
    rpc Publish (Result) returns (Result);
    rpc Subscribe (Result) returns (stream Result);
    }

    如未安装 proto 扩展请先安装

  • 执行 proto 命令

    1
    protoc --go_out=plugins=grpc:. pubsub.proto

3. 进入 pubsub 编辑 server.go 文件;内容如下

  
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
package main

import (
"context"
"fmt"
"github.com/docker/docker/pkg/pubsub"
grpc "google.golang.org/grpc"
"log"
"net"
"strings"

pb "pubsub/proto"
"time"
)

type PubSubService struct {
pub *pubsub.Publisher
}

func main() {
grpcServer := grpc.NewServer()
pb.RegisterPubSubServiceServer(grpcServer, NewPubSubService())

listener, err := net.Listen("tcp", ":1234")
if err != nil {
log.Fatal("listen err: ", err)
} else {
fmt.Println("Service Start.")
}
grpcServer.Serve(listener)
}

func NewPubSubService() *PubSubService {
return &PubSubService{pub: pubsub.NewPublisher(100*time.Millisecond, 10)}
}

func (pub *PubSubService) Publish(ctx context.Context, arg *pb.Result) (*pb.Result, error) {
value := arg.GetValue()
pub.pub.Publish(value)
return &pb.Result{Value: value}, nil
}

func (pub *PubSubService) Subscribe(arg *pb.Result, stream pb.PubSubService_SubscribeServer) error {
ch := pub.pub.SubscribeTopic(func(v interface{}) bool {
if key, ok := v.(string); ok {
if strings.HasPrefix(key, arg.GetValue()) {
return true
}
}
return false
})

for v := range ch {
if err := stream.Send(&pb.Result{Value: v.(string)}); err != nil {
return err
}
}
return nil
}

4. 进入 subscribe 目录,编写 subscribe.go 内容如下

  
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
package main

import (
"context"
"fmt"
"google.golang.org/grpc"
"io"
"log"
pb "pubsub/proto"
)

func main() {
conn, err := grpc.Dial("127.0.0.1:1234", grpc.WithInsecure())
if err != nil {
log.Fatal(err)
}
defer conn.Close()

client := pb.NewPubSubServiceClient(conn)

stream, err := client.Subscribe(
context.Background(),
&pb.Result{Value: "docker:"},
)
if err != nil {
log.Fatal(err)
}

for {
reply, err := stream.Recv()
if err != nil {
if err == io.EOF {
break
}
log.Fatal(err)
}
fmt.Println(reply.GetValue())
}


stream, err = client.Subscribe(
context.Background(),
&pb.Result{Value: "docker:"},
)
if err != nil {
log.Fatal(err)
}

for {
reply, err := stream.Recv()
if err != nil {
if err == io.EOF {
break
}
log.Fatal(err)
}
fmt.Println(reply.GetValue())
}
}

5. 进入 publisher 目录,编写 publisher.go 内容如下

  
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
package main

import (
"context"
"fmt"
"log"
pb "pubsub/proto"

grpc "google.golang.org/grpc"
)

func main() {
conn, err := grpc.Dial("127.0.0.1:1234", grpc.WithInsecure())
if err != nil {
log.Fatal(err)
}
defer conn.Close()

client := pb.NewPubSubServiceClient(conn)
str, err := client.Publish(
context.Background(),
&pb.Result{Value: "docker: hello Docker"},
)
if err != nil {
log.Fatal(err)
} else {
fmt.Println("Publish: ", str.GetValue())
}
}

6. 启动服务命令

  
1
2
3
4
5
6
7
8
9
进入根目录执行
go run server.go // 启动服务
进入 subscribe 目录执行
go run subscribe.go // 订阅服务
进入 publisher 目录执行
go run publisher.go // 发布

执行 发布之后,就能通过订阅窗口
有内容输出 docker: hello Docker

本博客所有文章除特别声明外,均采用 CC BY-SA 4.0 协议 ,转载请注明出处!