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：
./autogen.sh
./configure
make
make install
最后设置环境变量即可：export LD_LIBRARY_PATH=/usr/local/lib
3、安装 golang protobuf
go get -u github.com/golang/protobuf/proto // golang protobuf 库
go 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
syntax = "proto3";
option objc_class_prefix = "HLW";
package helloworld;
// The greeting service definition.
service Greeter {
// Sends a greeting
rpc SayHello (HelloRequest) returns (HelloReply) {}
}
// The request message containing the user's name.
message HelloRequest {
string name = 1;
}
// The response message containing the greetings
message HelloReply {
string message = 1;
}
- 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：
protoc --go_out=plugins=grpc:. helloworld.proto
ls
helloworld.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 // Code generated by protoc-gen-go. DO NOT EDIT.
2 // source: helloworld.proto
3
4 package helloworld
5
6 import (
7 context "context"
8 fmt "fmt"
9 proto "github.com/golang/protobuf/proto"
10 grpc "google.golang.org/grpc"
11 math "math"
12 )
13
14 // Reference imports to suppress errors if they are not otherwise used.
15 var _ = proto.Marshal
16 var _ = fmt.Errorf
17 var _ = math.Inf
18
19 // This is a compile-time assertion to ensure that this generated file
20 // is compatible with the proto package it is being compiled against.
21 // A compilation error at this line likely means your copy of the
22 // proto package needs to be updated.
23 const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
24
25 // The request message containing the user's name.
26 type HelloRequest struct {
27 Name string `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
28 XXX_NoUnkeyedLiteral struct{} `json:"-"`
29 XXX_unrecognized []byte `json:"-"`
30 XXX_sizecache int32 `json:"-"`
31 }
32
33 func (m *HelloRequest) Reset() { *m = HelloRequest{} }
34 func (m *HelloRequest) String() string { return proto.CompactTextString(m) }
35 func (*HelloRequest) ProtoMessage() {}
36 func (*HelloRequest) Descriptor() ([]byte, []int) {
37 return fileDescriptor_17b8c58d586b62f2, []int{0}
38 }
39
40 func (m *HelloRequest) XXX_Unmarshal(b []byte) error {
41 return xxx_messageInfo_HelloRequest.Unmarshal(m, b)
42 }
43 func (m *HelloRequest) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
44 return xxx_messageInfo_HelloRequest.Marshal(b, m, deterministic)
45 }
46 func (m *HelloRequest) XXX_Merge(src proto.Message) {
47 xxx_messageInfo_HelloRequest.Merge(m, src)
48 }
49 func (m *HelloRequest) XXX_Size() int {
50 return xxx_messageInfo_HelloRequest.Size(m)
51 }
52 func (m *HelloRequest) XXX_DiscardUnknown() {
53 xxx_messageInfo_HelloRequest.DiscardUnknown(m)
54 }
55
56 var xxx_messageInfo_HelloRequest proto.InternalMessageInfo
57
58 func (m *HelloRequest) GetName() string {
59 if m != nil {
60 return m.Name
61 }
62 return ""
63 }
64
65 // The response message containing the greetings
66 type HelloReply struct {
67 Message string `protobuf:"bytes,1,opt,name=message,proto3" json:"message,omitempty"`
68 XXX_NoUnkeyedLiteral struct{} `json:"-"`
69 XXX_unrecognized []byte `json:"-"`
70 XXX_sizecache int32 `json:"-"`
71 }
72
73 func (m *HelloReply) Reset() { *m = HelloReply{} }
74 func (m *HelloReply) String() string { return proto.CompactTextString(m) }
75 func (*HelloReply) ProtoMessage() {}
76 func (*HelloReply) Descriptor() ([]byte, []int) {
77 return fileDescriptor_17b8c58d586b62f2, []int{1}
78 }
79
80 func (m *HelloReply) XXX_Unmarshal(b []byte) error {
81 return xxx_messageInfo_HelloReply.Unmarshal(m, b)
82 }
83 func (m *HelloReply) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
84 return xxx_messageInfo_HelloReply.Marshal(b, m, deterministic)
85 }
86 func (m *HelloReply) XXX_Merge(src proto.Message) {
87 xxx_messageInfo_HelloReply.Merge(m, src)
88 }
89 func (m *HelloReply) XXX_Size() int {
90 return xxx_messageInfo_HelloReply.Size(m)
91 }
92 func (m *HelloReply) XXX_DiscardUnknown() {
93 xxx_messageInfo_HelloReply.DiscardUnknown(m)
94 }
95
96 var xxx_messageInfo_HelloReply proto.InternalMessageInfo
97
98 func (m *HelloReply) GetMessage() string {
99 if m != nil {
100 return m.Message
101 }
102 return ""
103 }
104
105 func init() {
106 proto.RegisterType((*HelloRequest)(nil), "helloworld.HelloRequest")
107 proto.RegisterType((*HelloReply)(nil), "helloworld.HelloReply")
108 }
109
110 func init() { proto.RegisterFile("helloworld.proto", fileDescriptor_17b8c58d586b62f2) }
111
112 var fileDescriptor_17b8c58d586b62f2 = []byte{
113 // 149 bytes of a gzipped FileDescriptorProto
114 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0xc8, 0x48, 0xcd, 0xc9,
115 0xc9, 0x2f, 0xcf, 0x2f, 0xca, 0x49, 0xd1, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0xe2, 0x42, 0x88,
116 0x28, 0x29, 0x71, 0xf1, 0x78, 0x80, 0x78, 0x41, 0xa9, 0x85, 0xa5, 0xa9, 0xc5, 0x25, 0x42, 0x42,
117 0x5c, 0x2c, 0x79, 0x89, 0xb9, 0xa9, 0x12, 0x8c, 0x0a, 0x8c, 0x1a, 0x9c, 0x41, 0x60, 0xb6, 0x92,
118 0x1a, 0x17, 0x17, 0x54, 0x4d, 0x41, 0x4e, 0xa5, 0x90, 0x04, 0x17, 0x7b, 0x6e, 0x6a, 0x71, 0x71,
119 0x62, 0x3a, 0x4c, 0x11, 0x8c, 0x6b, 0xe4, 0xc9, 0xc5, 0xee, 0x5e, 0x94, 0x9a, 0x5a, 0x92, 0x5a,
120 0x24, 0x64, 0xc7, 0xc5, 0x11, 0x9c, 0x58, 0x09, 0xd6, 0x25, 0x24, 0xa1, 0x87, 0xe4, 0x02, 0x64,
121 0xcb, 0xa4, 0xc4, 0xb0, 0xc8, 0x14, 0xe4, 0x54, 0x2a, 0x31, 0x38, 0xb1, 0x2d, 0x62, 0x62, 0xf6,
122 0xf0, 0x09, 0x4f, 0x62, 0x03, 0xbb, 0xd8, 0x18, 0x10, 0x00, 0x00, 0xff, 0xff, 0xbe, 0xde, 0x1d,
123 0x2e, 0xc5, 0x00, 0x00, 0x00,
124 }
125
126 // Reference imports to suppress errors if they are not otherwise used.
127 var _ context.Context
128 var _ grpc.ClientConn
129
130 // This is a compile-time assertion to ensure that this generated file
131 // is compatible with the grpc package it is being compiled against.
132 const _ = grpc.SupportPackageIsVersion4
133
134 // GreeterClient is the client API for Greeter service.
135 //
136 // For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
137 type GreeterClient interface {
138 // Sends a greeting
139 SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error)
140 }
141
142 type greeterClient struct {
143 cc *grpc.ClientConn
144 }
145
146 func NewGreeterClient(cc *grpc.ClientConn) GreeterClient {
147 return &greeterClient{cc}
148 }
149
150 func (c *greeterClient) SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error) {
151 out := new(HelloReply)
152 err := c.cc.Invoke(ctx, "/helloworld.Greeter/SayHello", in, out, opts...)
153 if err != nil {
154 return nil, err
155 }
156 return out, nil
157 }
158
159 // GreeterServer is the server API for Greeter service.
160 type GreeterServer interface {
161 // Sends a greeting
162 SayHello(context.Context, *HelloRequest) (*HelloReply, error)
163 }
164
165 func RegisterGreeterServer(s *grpc.Server, srv GreeterServer) {
166 s.RegisterService(&_Greeter_serviceDesc, srv)
167 }
168
169 func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
170 in := new(HelloRequest)
171 if err := dec(in); err != nil {
172 return nil, err
173 }
174 if interceptor == nil {
175 return srv.(GreeterServer).SayHello(ctx, in)
176 }
177 info := &grpc.UnaryServerInfo{
178 Server: srv,
179 FullMethod: "/helloworld.Greeter/SayHello",
180 }
181 handler := func(ctx context.Context, req interface{}) (interface{}, error) {
182 return srv.(GreeterServer).SayHello(ctx, req.(*HelloRequest))
183 }
184 return interceptor(ctx, in, info, handler)
185 }
186
187 var _Greeter_serviceDesc = grpc.ServiceDesc{
188 ServiceName: "helloworld.Greeter",
189 HandlerType: (*GreeterServer)(nil),
190 Methods: []grpc.MethodDesc{
191 {
192 MethodName: "SayHello",
193 Handler: _Greeter_SayHello_Handler,
194 },
195 },
196 Streams: []grpc.StreamDesc{},
197 Metadata: "helloworld.proto",
198 }
View Code
3、服务器程序
package main
import (
"log"
"net"
pb "test_grpc/helloworld"
"google.golang.org/grpc"
"golang.org/x/net/context"
)
const (
PORT = ":50001"
)
type server struct {}
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
log.Println("request: ", in.Name)
return &pb.HelloReply{Message: "Hello " + in.Name}, nil
}
func main() {
lis, err := net.Listen("tcp", PORT)
if err != nil {
log.Fatalf("failed to listen: %v", err)
}
s := grpc.NewServer()
pb.RegisterGreeterServer(s, &server{})
log.Println("rpc服务已经开启")
s.Serve(lis)
}
4、客户端程序
package main
import (
"log"
"os"
pb "test_grpc/helloworld"
"golang.org/x/net/context"
"google.golang.org/grpc"
)
const (
address = "localhost:50001"
)
func main() {
conn, err := grpc.Dial(address, grpc.WithInsecure())
if err != nil {
log.Fatalf("did not connect: %v", err)
}
defer conn.Close()
c := pb.NewGreeterClient(conn)
name := "lin"
if len(os.Args) > 1 {
name = os.Args[1]
}
r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
if err != nil {
log.Fatalf("could not greet: %v", err)
}
log.Println(r.Message)
}
