Golang gRPC 使用

一、概念

1、gRPC默认使用protocol buffers，这是google开源的一套成熟的结构数据序列化机制（当然也可以使用其他数据格式如JSON），可以用proto files创建gRPC服务，用protocol buffers消息类型来定义方法参数和返回类型。

二、安装

1、yum install autoconf automake libtool （centos 系统）

2、protocal buffer安装

从 https://github.com/google/protobuf/releases下载安装包，解压，然后操作以下命令：

1./autogen.sh
2./configure
3make
4make install

最后设置环境变量即可：export LD_LIBRARY_PATH=/usr/local/lib

3、安装 golang protobuf

1go get -u github.com/golang/protobuf/proto // golang protobuf 库
2go get -u github.com/golang/protobuf/protoc-gen-go //protoc --go_out 工具

4、安装 gRPC-go

go get google.golang.org/grpc

无法下载的话去 https://github.com/grpc/grpc-go 下载

三、使用

1、编写 proto 文件，helloworld.proto

1syntax = "proto3";
2
3option objc_class_prefix = "HLW";
4
5package helloworld;
6
7// The greeting service definition.
8service Greeter {
9  // Sends a greeting
10  rpc SayHello (HelloRequest) returns (HelloReply) {}
11}
12
13// The request message containing the user's name.
14message HelloRequest {
15  string name = 1;
16}
17
18// The response message containing the greetings
19message HelloReply {
20  string message = 1;
21}

syntax="proto3":指定protobuf的版本
package helloworld_:声明一个报名，一般与文件目录名相同_
import "xxx/xx.proto":导入其他的包，这样你就可以使用其他的包的数据结构
required、optional、repeated:表示该字段是否必须填充；required表示必须指定且只能指定一个；当optional表示可选，可指定也可不指定，但不可超过一个不指定值的时候会采用空值，如string类型的字段会用字符串表示；repeated表示可以重复，类似与编程语言中的list
message Author：在一个message体内定义一个message结构体
enum：是枚举类型结构体
数字：字段的标识符，不可重复
数据类型： int32、int64、uint32、uint64、sint32、sint64、double、float、 string、bool、bytes、enum、message等等

2、使用protoc命令生成相关文件：

1protoc --go_out=plugins=grpc:. helloworld.proto
2ls
3helloworld.pb.go    helloworld.proto

这里用了plugins选项，提供对grpc的支持，否则不会生成Service的接口，方便编写服务器和客户端程序

helloworld.pb.go 文件如下：

1  1 // Code generated by protoc-gen-go. DO NOT EDIT.
2  2 // source: helloworld.proto
3  3 
4  4 package helloworld
5  5 
6  6 import (
7  7     context "context"
8  8     fmt "fmt"
9  9     proto "github.com/golang/protobuf/proto"
10 10     grpc "google.golang.org/grpc"
11 11     math "math"
12 12 )
13 13 
14 14 // Reference imports to suppress errors if they are not otherwise used.
15 15 var _ = proto.Marshal
16 16 var _ = fmt.Errorf
17 17 var _ = math.Inf
18 18 
19 19 // This is a compile-time assertion to ensure that this generated file
20 20 // is compatible with the proto package it is being compiled against.
21 21 // A compilation error at this line likely means your copy of the
22 22 // proto package needs to be updated.
23 23 const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
24 24 
25 25 // The request message containing the user's name.
26 26 type HelloRequest struct {
27 27     Name                 string   `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
28 28     XXX_NoUnkeyedLiteral struct{} `json:"-"`
29 29     XXX_unrecognized     []byte   `json:"-"`
30 30     XXX_sizecache        int32    `json:"-"`
31 31 }
32 32 
33 33 func (m *HelloRequest) Reset()         { *m = HelloRequest{} }
34 34 func (m *HelloRequest) String() string { return proto.CompactTextString(m) }
35 35 func (*HelloRequest) ProtoMessage()    {}
36 36 func (*HelloRequest) Descriptor() ([]byte, []int) {
37 37     return fileDescriptor_17b8c58d586b62f2, []int{0}
38 38 }
39 39 
40 40 func (m *HelloRequest) XXX_Unmarshal(b []byte) error {
41 41     return xxx_messageInfo_HelloRequest.Unmarshal(m, b)
42 42 }
43 43 func (m *HelloRequest) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
44 44     return xxx_messageInfo_HelloRequest.Marshal(b, m, deterministic)
45 45 }
46 46 func (m *HelloRequest) XXX_Merge(src proto.Message) {
47 47     xxx_messageInfo_HelloRequest.Merge(m, src)
48 48 }
49 49 func (m *HelloRequest) XXX_Size() int {
50 50     return xxx_messageInfo_HelloRequest.Size(m)
51 51 }
52 52 func (m *HelloRequest) XXX_DiscardUnknown() {
53 53     xxx_messageInfo_HelloRequest.DiscardUnknown(m)
54 54 }
55 55 
56 56 var xxx_messageInfo_HelloRequest proto.InternalMessageInfo
57 57 
58 58 func (m *HelloRequest) GetName() string {
59 59     if m != nil {
60 60         return m.Name
61 61     }
62 62     return ""
63 63 }
64 64 
65 65 // The response message containing the greetings
66 66 type HelloReply struct {
67 67     Message              string   `protobuf:"bytes,1,opt,name=message,proto3" json:"message,omitempty"`
68 68     XXX_NoUnkeyedLiteral struct{} `json:"-"`
69 69     XXX_unrecognized     []byte   `json:"-"`
70 70     XXX_sizecache        int32    `json:"-"`
71 71 }
72 72 
73 73 func (m *HelloReply) Reset()         { *m = HelloReply{} }
74 74 func (m *HelloReply) String() string { return proto.CompactTextString(m) }
75 75 func (*HelloReply) ProtoMessage()    {}
76 76 func (*HelloReply) Descriptor() ([]byte, []int) {
77 77     return fileDescriptor_17b8c58d586b62f2, []int{1}
78 78 }
79 79 
80 80 func (m *HelloReply) XXX_Unmarshal(b []byte) error {
81 81     return xxx_messageInfo_HelloReply.Unmarshal(m, b)
82 82 }
83 83 func (m *HelloReply) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
84 84     return xxx_messageInfo_HelloReply.Marshal(b, m, deterministic)
85 85 }
86 86 func (m *HelloReply) XXX_Merge(src proto.Message) {
87 87     xxx_messageInfo_HelloReply.Merge(m, src)
88 88 }
89 89 func (m *HelloReply) XXX_Size() int {
90 90     return xxx_messageInfo_HelloReply.Size(m)
91 91 }
92 92 func (m *HelloReply) XXX_DiscardUnknown() {
93 93     xxx_messageInfo_HelloReply.DiscardUnknown(m)
94 94 }
95 95 
96 96 var xxx_messageInfo_HelloReply proto.InternalMessageInfo
97 97 
98 98 func (m *HelloReply) GetMessage() string {
99 99     if m != nil {
100100         return m.Message
101101     }
102102     return ""
103103 }
104104 
105105 func init() {
106106     proto.RegisterType((*HelloRequest)(nil), "helloworld.HelloRequest")
107107     proto.RegisterType((*HelloReply)(nil), "helloworld.HelloReply")
108108 }
109109 
110110 func init() { proto.RegisterFile("helloworld.proto", fileDescriptor_17b8c58d586b62f2) }
111111 
112112 var fileDescriptor_17b8c58d586b62f2 = []byte{
113113     // 149 bytes of a gzipped FileDescriptorProto
114114     0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0xc8, 0x48, 0xcd, 0xc9,
115115     0xc9, 0x2f, 0xcf, 0x2f, 0xca, 0x49, 0xd1, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0xe2, 0x42, 0x88,
116116     0x28, 0x29, 0x71, 0xf1, 0x78, 0x80, 0x78, 0x41, 0xa9, 0x85, 0xa5, 0xa9, 0xc5, 0x25, 0x42, 0x42,
117117     0x5c, 0x2c, 0x79, 0x89, 0xb9, 0xa9, 0x12, 0x8c, 0x0a, 0x8c, 0x1a, 0x9c, 0x41, 0x60, 0xb6, 0x92,
118118     0x1a, 0x17, 0x17, 0x54, 0x4d, 0x41, 0x4e, 0xa5, 0x90, 0x04, 0x17, 0x7b, 0x6e, 0x6a, 0x71, 0x71,
119119     0x62, 0x3a, 0x4c, 0x11, 0x8c, 0x6b, 0xe4, 0xc9, 0xc5, 0xee, 0x5e, 0x94, 0x9a, 0x5a, 0x92, 0x5a,
120120     0x24, 0x64, 0xc7, 0xc5, 0x11, 0x9c, 0x58, 0x09, 0xd6, 0x25, 0x24, 0xa1, 0x87, 0xe4, 0x02, 0x64,
121121     0xcb, 0xa4, 0xc4, 0xb0, 0xc8, 0x14, 0xe4, 0x54, 0x2a, 0x31, 0x38, 0xb1, 0x2d, 0x62, 0x62, 0xf6,
122122     0xf0, 0x09, 0x4f, 0x62, 0x03, 0xbb, 0xd8, 0x18, 0x10, 0x00, 0x00, 0xff, 0xff, 0xbe, 0xde, 0x1d,
123123     0x2e, 0xc5, 0x00, 0x00, 0x00,
124124 }
125125 
126126 // Reference imports to suppress errors if they are not otherwise used.
127127 var _ context.Context
128128 var _ grpc.ClientConn
129129 
130130 // This is a compile-time assertion to ensure that this generated file
131131 // is compatible with the grpc package it is being compiled against.
132132 const _ = grpc.SupportPackageIsVersion4
133133 
134134 // GreeterClient is the client API for Greeter service.
135135 //
136136 // For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
137137 type GreeterClient interface {
138138     // Sends a greeting
139139     SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error)
140140 }
141141 
142142 type greeterClient struct {
143143     cc *grpc.ClientConn
144144 }
145145 
146146 func NewGreeterClient(cc *grpc.ClientConn) GreeterClient {
147147     return &greeterClient{cc}
148148 }
149149 
150150 func (c *greeterClient) SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error) {
151151     out := new(HelloReply)
152152     err := c.cc.Invoke(ctx, "/helloworld.Greeter/SayHello", in, out, opts...)
153153     if err != nil {
154154         return nil, err
155155     }
156156     return out, nil
157157 }
158158 
159159 // GreeterServer is the server API for Greeter service.
160160 type GreeterServer interface {
161161     // Sends a greeting
162162     SayHello(context.Context, *HelloRequest) (*HelloReply, error)
163163 }
164164 
165165 func RegisterGreeterServer(s *grpc.Server, srv GreeterServer) {
166166     s.RegisterService(&_Greeter_serviceDesc, srv)
167167 }
168168 
169169 func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
170170     in := new(HelloRequest)
171171     if err := dec(in); err != nil {
172172         return nil, err
173173     }
174174     if interceptor == nil {
175175         return srv.(GreeterServer).SayHello(ctx, in)
176176     }
177177     info := &grpc.UnaryServerInfo{
178178         Server:     srv,
179179         FullMethod: "/helloworld.Greeter/SayHello",
180180     }
181181     handler := func(ctx context.Context, req interface{}) (interface{}, error) {
182182         return srv.(GreeterServer).SayHello(ctx, req.(*HelloRequest))
183183     }
184184     return interceptor(ctx, in, info, handler)
185185 }
186186 
187187 var _Greeter_serviceDesc = grpc.ServiceDesc{
188188     ServiceName: "helloworld.Greeter",
189189     HandlerType: (*GreeterServer)(nil),
190190     Methods: []grpc.MethodDesc{
191191         {
192192             MethodName: "SayHello",
193193             Handler:    _Greeter_SayHello_Handler,
194194         },
195195     },
196196     Streams:  []grpc.StreamDesc{},
197197     Metadata: "helloworld.proto",
198198 }

View Code

3、服务器程序

1package main
2
3import (
4    "log"
5    "net"
6
7    pb "test_grpc/helloworld"
8    "google.golang.org/grpc"
9    "golang.org/x/net/context"
10)
11
12const (
13    PORT = ":50001"
14)
15
16type server struct {}
17
18func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
19    log.Println("request: ", in.Name)
20    return &pb.HelloReply{Message: "Hello " + in.Name}, nil
21}
22
23func main() {
24    lis, err := net.Listen("tcp", PORT)
25
26    if err != nil {
27        log.Fatalf("failed to listen: %v", err)
28    }
29
30    s := grpc.NewServer()
31    pb.RegisterGreeterServer(s, &server{})
32    log.Println("rpc服务已经开启")
33    s.Serve(lis)
34}

4、客户端程序

1package main
2
3import (
4    "log"
5    "os"
6
7    pb "test_grpc/helloworld"
8    "golang.org/x/net/context"
9    "google.golang.org/grpc"
10)
11
12const (
13    address = "localhost:50001"
14)
15
16func main() {
17    conn, err := grpc.Dial(address, grpc.WithInsecure())
18
19    if err != nil {
20        log.Fatalf("did not connect: %v", err)
21    }
22
23    defer conn.Close()
24
25    c := pb.NewGreeterClient(conn)
26
27    name := "lin"
28    if len(os.Args) > 1 {
29        name = os.Args[1]
30    }
31
32    r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
33
34    if err != nil {
35        log.Fatalf("could not greet: %v", err)
36    }
37
38    log.Println(r.Message)
39}

一、概念

二、安装

三、使用

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