本篇将介绍grpc_validator，它可以对gRPC数据的输入和输出进行验证。
这里复用上一篇文章的代码。
这里使用第三方插件go-proto-validators 自动生成验证规则。
地址：https://github.com/mwitkow/go-proto-validators
$ go get github.com/mwitkow/go-proto-validators
syntax = "proto3";
package proto;
option go_package = "./proto;proto";
// validator.proto是github.com/mwitkow/go-proto-validators/validator.proto
import "validator.proto";
message InnerMessage {
// some_integer can only be in range (1, 100).
int32 some_integer = 1 [(validator.field) = {int_gt: 0, int_lt: 100}];
// some_float can only be in range (0;1).
double some_float = 2 [(validator.field) = {float_gte: 0, float_lte: 1}];
}
message OuterMessage {
// important_string must be a lowercase alpha-numeric of 5 to 30 characters (RE2 syntax).
string important_string = 1 [(validator.field) = {regex: "^[a-z]{2,5}$"}];
// proto3 doesn't have `required`, the `msg_exist` enforces presence of InnerMessage.
InnerMessage inner = 2 [(validator.field) = {msg_exists: true}];
}
service Simple {
rpc Route (InnerMessage) returns (OuterMessage) {};
}
validator.proto文件内容：
// Copyright 2016 Michal Witkowski. All Rights Reserved.
// See LICENSE for licensing terms.
// Protocol Buffers extensions for defining auto-generateable validators for messages.
// TODO(mwitkow): Add example.
syntax = "proto2";
package validator;
import "google/protobuf/descriptor.proto";
option go_package = "github.com/mwitkow/go-proto-validators;validator";
// TODO(mwitkow): Email protobuf-global-extension-registry@google.com to get an extension ID.
extend google.protobuf.FieldOptions {
optional FieldValidator field = 65020;
}
extend google.protobuf.OneofOptions {
optional OneofValidator oneof = 65021;
}
message FieldValidator {
// Uses a Golang RE2-syntax regex to match the field contents.
optional string regex = 1;
// Field value of integer strictly greater than this value.
optional int64 int_gt = 2;
// Field value of integer strictly smaller than this value.
optional int64 int_lt = 3;
// Used for nested message types, requires that the message type exists.
optional bool msg_exists = 4;
// Human error specifies a user-customizable error that is visible to the user.
optional string human_error = 5;
// Field value of double strictly greater than this value.
// Note that this value can only take on a valid floating point
// value. Use together with float_epsilon if you need something more specific.
optional double float_gt = 6;
// Field value of double strictly smaller than this value.
// Note that this value can only take on a valid floating point
// value. Use together with float_epsilon if you need something more specific.
optional double float_lt = 7;
// Field value of double describing the epsilon within which
// any comparison should be considered to be true. For example,
// when using float_gt = 0.35, using a float_epsilon of 0.05
// would mean that any value above 0.30 is acceptable. It can be
// thought of as a {float_value_condition} +- {float_epsilon}.
// If unset, no correction for floating point inaccuracies in
// comparisons will be attempted.
optional double float_epsilon = 8;
// Floating-point value compared to which the field content should be greater or equal.
optional double float_gte = 9;
// Floating-point value compared to which the field content should be smaller or equal.
optional double float_lte = 10;
// Used for string fields, requires the string to be not empty (i.e different from "").
optional bool string_not_empty = 11;
// Repeated field with at least this number of elements.
optional int64 repeated_count_min = 12;
// Repeated field with at most this number of elements.
optional int64 repeated_count_max = 13;
// Field value of length greater than this value.
optional int64 length_gt = 14;
// Field value of length smaller than this value.
optional int64 length_lt = 15;
// Field value of length strictly equal to this value.
optional int64 length_eq = 16;
// Requires that the value is in the enum.
optional bool is_in_enum = 17;
// Ensures that a string value is in UUID format.
// uuid_ver specifies the valid UUID versions. Valid values are: 0-5.
// If uuid_ver is 0 all UUID versions are accepted.
optional int32 uuid_ver = 18;
}
message OneofValidator {
// Require that one of the oneof fields is set.
optional bool required = 1;
}
$ go get github.com/mwitkow/go-proto-validators/protoc-gen-govalidators
$ go install github.com/mwitkow/go-proto-validators/protoc-gen-govalidators
$ protoc --govalidators_out=. --go_out=plugins=grpc:. simple.proto
编译完成后，自动生成simple.pb.go和simple.validator.pb.go文件，simple.pb.go文件不再介绍，我们
看下simple.validator.pb.go文件。
// Code generated by protoc-gen-gogo. DO NOT EDIT.
// source: simple.proto
package proto
import (
fmt "fmt"
math "math"
proto "github.com/golang/protobuf/proto"
_ "github.com/mwitkow/go-proto-validators"
regexp "regexp"
github_com_mwitkow_go_proto_validators "github.com/mwitkow/go-proto-validators"
)
// Reference imports to suppress errors if they are not otherwise used.
var _ = proto.Marshal
var _ = fmt.Errorf
var _ = math.Inf
func (this *InnerMessage) Validate() error {
if !(this.SomeInteger > 0) {
return github_com_mwitkow_go_proto_validators.FieldError("SomeInteger", fmt.Errorf(`value '%v' must be greater than '0'`, this.SomeInteger))
}
if !(this.SomeInteger < 100) {
return github_com_mwitkow_go_proto_validators.FieldError("SomeInteger", fmt.Errorf(`value '%v' must be less than '100'`, this.SomeInteger))
}
if !(this.SomeFloat >= 0) {
return github_com_mwitkow_go_proto_validators.FieldError("SomeFloat", fmt.Errorf(`value '%v' must be greater than or equal to '0'`, this.SomeFloat))
}
if !(this.SomeFloat <= 1) {
return github_com_mwitkow_go_proto_validators.FieldError("SomeFloat", fmt.Errorf(`value '%v' must be lower than or equal to '1'`, this.SomeFloat))
}
return nil
}
var _regex_OuterMessage_ImportantString = regexp.MustCompile(`^[a-z]{2,5}$`)
func (this *OuterMessage) Validate() error {
if !_regex_OuterMessage_ImportantString.MatchString(this.ImportantString) {
return github_com_mwitkow_go_proto_validators.FieldError("ImportantString", fmt.Errorf(`value '%v' must be a string conforming to regex "^[a-z]{2,5}$"`, this.ImportantString))
}
if nil == this.Inner {
return github_com_mwitkow_go_proto_validators.FieldError("Inner", fmt.Errorf("message must exist"))
}
if this.Inner != nil {
if err := github_com_mwitkow_go_proto_validators.CallValidatorIfExists(this.Inner); err != nil {
return github_com_mwitkow_go_proto_validators.FieldError("Inner", err)
}
}
return nil
}
里面自动生成了message中属性的验证规则。
package main
import (
"context"
grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
grpc_auth "github.com/grpc-ecosystem/go-grpc-middleware/auth"
grpc_zap "github.com/grpc-ecosystem/go-grpc-middleware/logging/zap"
grpc_recovery "github.com/grpc-ecosystem/go-grpc-middleware/recovery"
grpc_validator "github.com/grpc-ecosystem/go-grpc-middleware/validator"
pb "middleware/proto"
"middleware/server/middleware/auth"
"middleware/server/middleware/cred"
"middleware/server/middleware/recovery"
"middleware/server/middleware/zap"
"google.golang.org/grpc"
"log"
"net"
)
// SimpleService 定义我们的服务
type SimpleService struct{}
// Route 实现Route方法
func (s *SimpleService) Route(ctx context.Context, req *pb.InnerMessage) (*pb.OuterMessage, error) {
res := pb.OuterMessage{
ImportantString: "hello grpc validator",
Inner: req,
}
return &res, nil
}
const (
// Address 监听地址
Address string = ":8000"
// Network 网络通信协议
Network string = "tcp"
)
func main() {
// 监听本地端口
listener, err := net.Listen(Network, Address)
if err != nil {
log.Fatalf("net.Listen err: %v", err)
}
// 新建gRPC服务器实例
grpcServer := grpc.NewServer(
// TLS+Token认证
cred.TLSInterceptor(),
grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(
// 参数验证
grpc_validator.StreamServerInterceptor(),
// grpc_zap日志记录
grpc_zap.StreamServerInterceptor(zap.ZapInterceptor()),
// grpc_auth认证
grpc_auth.StreamServerInterceptor(auth.AuthInterceptor),
// grpc_recovery恢复
grpc_recovery.StreamServerInterceptor(recovery.RecoveryInterceptor()),
)),
grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
// 参数验证
grpc_validator.UnaryServerInterceptor(),
// grpc_zap日志记录
grpc_zap.UnaryServerInterceptor(zap.ZapInterceptor()),
// grpc_auth认证
grpc_auth.UnaryServerInterceptor(auth.AuthInterceptor),
// grpc_recovery恢复
grpc_recovery.UnaryServerInterceptor(recovery.RecoveryInterceptor()),
)),
)
// 在gRPC服务器注册我们的服务
pb.RegisterSimpleServer(grpcServer, &SimpleService{})
log.Println(Address + " net.Listing with TLS and token...")
//用服务器 Serve() 方法以及我们的端口信息区实现阻塞等待，直到进程被杀死或者 Stop() 被调用
err = grpcServer.Serve(listener)
if err != nil {
log.Fatalf("grpcServer.Serve err: %v", err)
}
}
[root@zsx middleware]# go run server.go
2023/02/11 21:42:01 :8000 net.Listing with TLS and token...
package main
import (
"context"
"middleware/token"
pb "middleware/proto"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"log"
)
// Address 连接地址
const Address string = ":8000"
var grpcClient pb.SimpleClient
func main() {
//从输入的证书文件中为客户端构造TLS凭证
creds, err := credentials.NewClientTLSFromFile("./cert/server/server.pem", "test.example.com")
if err != nil {
log.Fatalf("Failed to create TLS credentials %v", err)
}
//构建Token
token := auth.Token{
Value: "bearer grpc.auth.token",
}
// 连接服务器
conn, err := grpc.Dial(Address, grpc.WithTransportCredentials(creds), grpc.WithPerRPCCredentials(&token))
if err != nil {
log.Fatalf("net.Connect err: %v", err)
}
defer conn.Close()
// 建立gRPC连接
grpcClient = pb.NewSimpleClient(conn)
route()
}
// route 调用服务端Route方法
func route() {
// 创建发送结构体
req := pb.InnerMessage{
SomeInteger: 99,
SomeFloat: 1,
}
// 调用我们的服务(Route方法)
// 同时传入了一个 context.Context ，在有需要时可以让我们改变RPC的行为，比如超时/取消一个正在运行的RPC
res, err := grpcClient.Route(context.Background(), &req)
if err != nil {
log.Fatalf("Call Route err: %v", err)
}
// 打印返回值
log.Println(res)
}
[root@zsx middleware]# go run client.go
2023/02/11 21:44:11 important_string:"hello grpc validator" inner:{some_integer:99 some_float:1}
运行后，当输入不符合要求的数据：
// 创建发送结构体
req := pb.InnerMessage{
SomeInteger: 199,
SomeFloat: 1,
}
验证失败后，会有以下错误返回：
[root@zsx middleware]# go run client.go
2023/02/11 21:45:25 Call Route err: rpc error: code = InvalidArgument desc = invalid field SomeInteger: value '199' must be less than '100'
exit status 1
# 项目结构
$ tree middleware/
middleware/
├── cert
│ ├── ca.crt
│ ├── ca.csr
│ ├── ca.key
│ ├── ca.srl
│ ├── client
│ │ ├── client.csr
│ │ ├── client.key
│ │ └── client.pem
│ ├── openssl.cnf
│ └── server
│ ├── server.csr
│ ├── server.key
│ └── server.pem
├── client.go
├── go.mod
├── go.sum
├── log
│ └── debug.log
├── proto
│ ├── simple.pb.go
│ └── simple.validator.pb.go
├── server
│ └── middleware
│ ├── auth
│ │ └── auth.go
│ ├── cred
│ │ └── cred.go
│ ├── recovery
│ │ └── recovery.go
│ └── zap
│ └── zap.go
├── server.go
├── simple.proto
├── token
│ └── token.go
└── validator.proto
12 directories, 25 files
enum验证：
syntax = "proto3";
package proto;
option go_package = "./proto;enum";
import "validator.proto";
message SomeMsg {
Action do = 1 [(validator.field) = {is_in_enum: true}];
}
enum Action {
ALLOW = 0;
DENY = 1;
CHILL = 2;
}
UUID验证：
syntax = "proto3";
package proto;
option go_package = "./proto;uuid";
import "validator.proto";
message UUIDMsg {
// user_id must be a valid version 4 UUID.
string user_id = 1 [(validator.field) = {uuid_ver: 4, string_not_empty: true}];
}
go-grpc-middleware中grpc_validator集成go-proto-validators，我们只需要在编写proto时设好验证规
则，并把grpc_validator添加到gRPC服务端，就能完成gRPC的数据验证，很简单也很方便。