gRPC拦截器
简介
grpc服务端和客户端都提供了拦截器interceptor功能，功能类似中间件go-grpc-middleware，很适合在这里处理验证、日志等流程。
代码
proto
syntax = "proto3";
option go_package = ".;proto";
service Greeter{
rpc SayHello(HelloRequest) returns (HelloReply);
}
message HelloRequest{
string name = 1;
}
message HelloReply{
string message = 1;
}
protoc -I . hello.proto --go_out=plugins=grpc:.
.pb.go
// Code generated by protoc-gen-go. DO NOT EDIT.
// versions:
// protoc-gen-go v1.28.0
// protoc v3.19.4
// source: hello.proto
package proto
import (
context "context"
grpc "google.golang.org/grpc"
codes "google.golang.org/grpc/codes"
status "google.golang.org/grpc/status"
protoreflect "google.golang.org/protobuf/reflect/protoreflect"
protoimpl "google.golang.org/protobuf/runtime/protoimpl"
reflect "reflect"
sync "sync"
)
const (
// Verify that this generated code is sufficiently up-to-date.
_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
// Verify that runtime/protoimpl is sufficiently up-to-date.
_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
)
type HelloRequest struct {
state protoimpl.MessageState
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
Name string `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
}
func (x *HelloRequest) Reset() {
*x = HelloRequest{}
if protoimpl.UnsafeEnabled {
mi := &file_hello_proto_msgTypes[0]
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
ms.StoreMessageInfo(mi)
}
}
func (x *HelloRequest) String() string {
return protoimpl.X.MessageStringOf(x)
}
func (*HelloRequest) ProtoMessage() {}
func (x *HelloRequest) ProtoReflect() protoreflect.Message {
mi := &file_hello_proto_msgTypes[0]
if protoimpl.UnsafeEnabled && x != nil {
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
if ms.LoadMessageInfo() == nil {
ms.StoreMessageInfo(mi)
}
return ms
}
return mi.MessageOf(x)
}
// Deprecated: Use HelloRequest.ProtoReflect.Descriptor instead.
func (*HelloRequest) Descriptor() ([]byte, []int) {
return file_hello_proto_rawDescGZIP(), []int{0}
}
func (x *HelloRequest) GetName() string {
if x != nil {
return x.Name
}
return ""
}
type HelloReply struct {
state protoimpl.MessageState
sizeCache protoimpl.SizeCache
unknownFields protoimpl.UnknownFields
Message string `protobuf:"bytes,1,opt,name=message,proto3" json:"message,omitempty"`
}
func (x *HelloReply) Reset() {
*x = HelloReply{}
if protoimpl.UnsafeEnabled {
mi := &file_hello_proto_msgTypes[1]
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
ms.StoreMessageInfo(mi)
}
}
func (x *HelloReply) String() string {
return protoimpl.X.MessageStringOf(x)
}
func (*HelloReply) ProtoMessage() {}
func (x *HelloReply) ProtoReflect() protoreflect.Message {
mi := &file_hello_proto_msgTypes[1]
if protoimpl.UnsafeEnabled && x != nil {
ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
if ms.LoadMessageInfo() == nil {
ms.StoreMessageInfo(mi)
}
return ms
}
return mi.MessageOf(x)
}
// Deprecated: Use HelloReply.ProtoReflect.Descriptor instead.
func (*HelloReply) Descriptor() ([]byte, []int) {
return file_hello_proto_rawDescGZIP(), []int{1}
}
func (x *HelloReply) GetMessage() string {
if x != nil {
return x.Message
}
return ""
}
var File_hello_proto protoreflect.FileDescriptor
var file_hello_proto_rawDesc = []byte{
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}
var (
file_hello_proto_rawDescOnce sync.Once
file_hello_proto_rawDescData = file_hello_proto_rawDesc
)
func file_hello_proto_rawDescGZIP() []byte {
file_hello_proto_rawDescOnce.Do(func() {
file_hello_proto_rawDescData = protoimpl.X.CompressGZIP(file_hello_proto_rawDescData)
})
return file_hello_proto_rawDescData
}
var file_hello_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
var file_hello_proto_goTypes = []interface{}{
(*HelloRequest)(nil), // 0: HelloRequest
(*HelloReply)(nil), // 1: HelloReply
}
var file_hello_proto_depIdxs = []int32{
0, // 0: Greeter.SayHello:input_type -> HelloRequest
1, // 1: Greeter.SayHello:output_type -> HelloReply
1, // [1:2] is the sub-list for method output_type
0, // [0:1] is the sub-list for method input_type
0, // [0:0] is the sub-list for extension type_name
0, // [0:0] is the sub-list for extension extendee
0, // [0:0] is the sub-list for field type_name
}
func init() { file_hello_proto_init() }
func file_hello_proto_init() {
if File_hello_proto != nil {
return
}
if !protoimpl.UnsafeEnabled {
file_hello_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
switch v := v.(*HelloRequest); i {
case 0:
return &v.state
case 1:
return &v.sizeCache
case 2:
return &v.unknownFields
default:
return nil
}
}
file_hello_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
switch v := v.(*HelloReply); i {
case 0:
return &v.state
case 1:
return &v.sizeCache
case 2:
return &v.unknownFields
default:
return nil
}
}
}
type x struct{}
out := protoimpl.TypeBuilder{
File: protoimpl.DescBuilder{
GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
RawDescriptor: file_hello_proto_rawDesc,
NumEnums: 0,
NumMessages: 2,
NumExtensions: 0,
NumServices: 1,
},
GoTypes: file_hello_proto_goTypes,
DependencyIndexes: file_hello_proto_depIdxs,
MessageInfos: file_hello_proto_msgTypes,
}.Build()
File_hello_proto = out.File
file_hello_proto_rawDesc = nil
file_hello_proto_goTypes = nil
file_hello_proto_depIdxs = nil
}
// Reference imports to suppress errors if they are not otherwise used.
var _ context.Context
var _ grpc.ClientConnInterface
// This is a compile-time assertion to ensure that this generated file
// is compatible with the grpc package it is being compiled against.
const _ = grpc.SupportPackageIsVersion6
// GreeterClient is the client API for Greeter service.
//
// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://godoc.org/google.golang.org/grpc#ClientConn.NewStream.
type GreeterClient interface {
SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error)
}
type greeterClient struct {
cc grpc.ClientConnInterface
}
func NewGreeterClient(cc grpc.ClientConnInterface) GreeterClient {
return &greeterClient{cc}
}
func (c *greeterClient) SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error) {
out := new(HelloReply)
err := c.cc.Invoke(ctx, "/Greeter/SayHello", in, out, opts...)
if err != nil {
return nil, err
}
return out, nil
}
// GreeterServer is the server API for Greeter service.
type GreeterServer interface {
SayHello(context.Context, *HelloRequest) (*HelloReply, error)
}
// UnimplementedGreeterServer can be embedded to have forward compatible implementations.
type UnimplementedGreeterServer struct {
}
func (*UnimplementedGreeterServer) SayHello(context.Context, *HelloRequest) (*HelloReply, error) {
return nil, status.Errorf(codes.Unimplemented, "method SayHello not implemented")
}
func RegisterGreeterServer(s *grpc.Server, srv GreeterServer) {
s.RegisterService(&_Greeter_serviceDesc, srv)
}
func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
in := new(HelloRequest)
if err := dec(in); err != nil {
return nil, err
}
if interceptor == nil {
return srv.(GreeterServer).SayHello(ctx, in)
}
info := &grpc.UnaryServerInfo{
Server: srv,
FullMethod: "/Greeter/SayHello",
}
handler := func(ctx context.Context, req interface{}) (interface{}, error) {
return srv.(GreeterServer).SayHello(ctx, req.(*HelloRequest))
}
return interceptor(ctx, in, info, handler)
}
var _Greeter_serviceDesc = grpc.ServiceDesc{
ServiceName: "Greeter",
HandlerType: (*GreeterServer)(nil),
Methods: []grpc.MethodDesc{
{
MethodName: "SayHello",
Handler: _Greeter_SayHello_Handler,
},
},
Streams: []grpc.StreamDesc{},
Metadata: "hello.proto",
}
Server
package main
import (
"ShopBefore/rpc/grpc_interpretor/proto"
"context"
"fmt"
"google.golang.org/grpc"
"net"
"time"
)
type Server struct{}
func (s Server) SayHello(ctx context.Context, request *proto.HelloRequest) (*proto.HelloReply, error) {
time.Sleep(2 * time.Second)
return &proto.HelloReply{Message: "hello " + request.Name}, nil
}
func main() {
interceptorFunc := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
fmt.Println("接收到了一个新的请求")
res, err := handler(ctx, req)
fmt.Println("请求已完成")
return res, err
}
interceptor := grpc.UnaryInterceptor(interceptorFunc)
server := grpc.NewServer(interceptor)
proto.RegisterGreeterServer(server,&Server{})
listen, _ := net.Listen("tcp", ":8081")
_ = server.Serve(listen)
}
Client
package main
import (
"ShopBefore/rpc/grpc_interpretor/proto"
"context"
"fmt"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
"time"
)
func main() {
interceptorFunc := func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
start := time.Now()
err := invoker(ctx, method, req, reply, cc, opts...)
fmt.Printf("耗时:%s\n", time.Since(start))
return err
}
var opts []grpc.DialOption
opts = append(opts, grpc.WithUnaryInterceptor(interceptorFunc))
opts = append(opts, grpc.WithTransportCredentials(insecure.NewCredentials()))
conn, _ := grpc.Dial("localhost:8081", opts...)
defer conn.Close()
client := proto.NewGreeterClient(conn)
res, _ := client.SayHello(context.Background(), &proto.HelloRequest{Name: "番茄炒蛋"})
fmt.Println(res.Message)
}
以上拦截器可以拦截一元rpc请求(简单模式);代码中的error为了编写效率没有处理请忽略;