前言#
上篇介绍了go-grpc-middleware的grpc_zap、grpc_auth和grpc_recovery使用，本篇将介绍grpc_validator，它可以对gRPC数据的输入和输出进行验证。
创建proto文件，添加验证规则#
这里使用第三方插件go-proto-validators自动生成验证规则。
go get github.com/mwitkow/go-proto-validators
1.新建simple.proto文件
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``syntax = “proto3”;
package proto;
import “github.com/mwitkow/go-proto-validators/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){};
}``
代码import "github.com/mwitkow/go-proto-validators/validator.proto"，文件validator.proto需要import "google/protobuf/descriptor.proto";包，不然会报错。
google/protobuf地址：https://github.com/protocolbuffers/protobuf/tree/master/src/google/protobuf/descriptor.proto
把src文件夹中的protobuf目录下载到GOPATH目录下。
2.编译simple.proto文件
go get github.com/mwitkow/go-proto-validators/protoc-gen-govalidators
指令编译：protoc --govalidators_out=. --go_out=plugins=grpc:./ ./simple.proto
或者使用
VSCode-proto3插件，第一篇有介绍。只需要添加"--govalidators_out=."即可。
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`”protoc”: {
"path": "C:\\Go\\bin\\protoc.exe",
"compile_on_save": true,
"options": [
"--go_out=plugins=grpc:.",
"--govalidators_out=."
]
},`
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。
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``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”
)
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。
把grpc_validator验证拦截器添加到服务端#
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grpcServer := grpc.NewServer(cred.TLSInterceptor(), grpc.StreamInterceptor(grpc_middleware.ChainStreamServer( grpc_validator.StreamServerInterceptor(), grpc_auth.StreamServerInterceptor(auth.AuthInterceptor), grpc_zap.StreamServerInterceptor(zap.ZapInterceptor()), grpc_recovery.StreamServerInterceptor(recovery.RecoveryInterceptor()), )), grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer( grpc_validator.UnaryServerInterceptor(), grpc_auth.UnaryServerInterceptor(auth.AuthInterceptor), grpc_zap.UnaryServerInterceptor(zap.ZapInterceptor()), grpc_recovery.UnaryServerInterceptor(recovery.RecoveryInterceptor()), )), )
运行后，当输入数据验证失败后，会有以下错误返回
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Call Route err: rpc error: code = InvalidArgument desc = invalid field SomeInteger: value '101' must be less than '100'
其他类型验证规则设置#
enum验证
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`syntax = “proto3”;
package proto;
import “github.com/mwitkow/go-proto-validators/validator.proto”;
message SomeMsg {
Action do = 1 [(validator.field) = {is_in_enum : true}];
}
enum Action {
ALLOW = 0;
DENY = 1;
CHILL = 2;
}`
UUID验证
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`syntax = “proto3”;
package proto;
import “github.com/mwitkow/go-proto-validators/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}];
}`
总结#
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。
