hz usage(protobuf)

hz usage(protobuf).

Create a project based on protobuf IDL

new: Create a new project

  1. Create the protobuf IDL file in the current directory

    1. Create api.proto

      api.proto is an annotation file provided by hz, with the following content. Please import the file in the annotated proto file.

      If you want to expand the use of annotations on your own, please do not use “5” as the beginning of the sequence number to avoid conflicts. For example, “optional string xxx = 77777;”.

      // idl/api.proto; Annotation extension
syntax = "proto2";

package api;

import "google/protobuf/descriptor.proto";

option go_package = "/api";

extend google.protobuf.FieldOptions {
    optional string raw_body = 50101;
    optional string query = 50102;
    optional string header = 50103;
    optional string cookie = 50104;
    optional string body = 50105;
    optional string path = 50106;
    optional string vd = 50107;
    optional string form = 50108;
    optional string js_conv = 50109;
    optional string file_name = 50110;
    optional string none = 50111;

    // 50131~50160 used to extend field option by hz
    optional string form_compatible = 50131;
    optional string js_conv_compatible = 50132;
    optional string file_name_compatible = 50133;
    optional string none_compatible = 50134;
    // 50135 is reserved to vt_compatible
    // optional FieldRules vt_compatible = 50135;

    optional string go_tag = 51001;
}

extend google.protobuf.MethodOptions {
    optional string get = 50201;
    optional string post = 50202;
    optional string put = 50203;
    optional string delete = 50204;
    optional string patch = 50205;
    optional string options = 50206;
    optional string head = 50207;
    optional string any = 50208;
    optional string gen_path = 50301; // The path specified by the user when the client code is generated, with a higher priority than api_version
    optional string api_version = 50302; // Specify the value of the :version variable in path when the client code is generated
    optional string tag = 50303; // rpc tag, can be multiple, separated by commas
    optional string name = 50304; // Name of rpc
    optional string api_level = 50305; // Interface Level
    optional string serializer = 50306; // Serialization method
    optional string param = 50307; // Whether client requests take public parameters
    optional string baseurl = 50308; // Baseurl used in ttnet routing
    optional string handler_path = 50309; // handler_path specifies the path to generate the method

    // 50331~50360 used to extend method option by hz
    optional string handler_path_compatible = 50331; // handler_path specifies the path to generate the method
}

extend google.protobuf.EnumValueOptions {
    optional int32 http_code = 50401;

// 50431~50460 used to extend enum option by hz
}

extend google.protobuf.ServiceOptions {
    optional string base_domain = 50402;

    // 50731~50760 used to extend service option by hz
    optional string base_domain_compatible = 50731;
}

extend google.protobuf.MessageOptions {
    // optional FieldRules msg_vt = 50111;

    optional string reserve = 50830;
    // 550831 is reserved to msg_vt_compatible
    // optional FieldRules msg_vt_compatible = 50831;
}

    2. Create Master IDL

      // idl/hello/hello.proto
syntax = "proto3";

package hello;

option go_package = "hertz/hello";

import "api.proto";

message HelloReq {
   string Name = 1[(api.query)="name"];
}

message HelloResp {
   string RespBody = 1;
}

service HelloService {
   rpc Method1(HelloReq) returns(HelloResp) {
      option (api.get) = "/hello";
   }
}

  2. Create a new project

    # Execute is not under GOPATH, add go mod name after "-module", if the dependencies of the main IDL and the main IDL are not in the same path, you need to add the "-I" option, its meaning is IDL search path, equivalent to the option "-I" for protoc

hz new -module example/m -I idl -idl idl/hello/hello.proto

# Tidy & get dependencies
go mod tidy

    # Execute under GOPATH, if the dependencies of the main IDL and the main IDL are not in the same path, you need to add the "-I" option, its meaning is IDL search path, equivalent to the option "-I" for protoc
hz new -I idl -idl idl/hello/hello.proto

go mod init

# Tidy & get dependencies
go mod tidy

  3. Modify the handler and add your own logic

    // handler path: biz/handler/hello/hello_service.go
// where "/hello" is the last level of go_package in protobuf IDL
// "hello_service.go" is the name of the service in protobuf IDL, all methods defined by the service will be generated in this file

// Method1 .
// @router /hello [GET]
func Method1(ctx context.Context, c *app.RequestContext) {
   var err error
   var req hello.HelloReq
   err = c.BindAndValidate(&req)
   if err != nil {
      c.String(400, err.Error())
      return
   }

   resp := new(hello.HelloResp)

   // You can modify the logic of the entire function, not just the current template
   resp.RespBody = "hello," + req.Name // added logic

   c.JSON(200, resp)
}

  4. Compile the project

    go build

  5. Run the project and test it

    Run the project：

    ./{{your binary}}

    Test：

    curl --location --request GET 'http://127.0.0.1:8888/hello?name=hertz'

    If it returns {"RespBody":"hello,hertz"}, it works.

update: Update an existing Hertz project

  1. If your protobuf IDL is updated, for example:

    // idl/hello/hello.proto
syntax = "proto3";

package hello;

option go_package = "hertz/hello";

import "api.proto";

message HelloReq {
   string Name = 1[(api.query)="name"];
}

message HelloResp {
   string RespBody = 1;
}

message OtherReq {
   string Other = 1[(api.body)="other"];
}

message OtherResp {
   string Resp = 1;
}

service HelloService {
   rpc Method1(HelloReq) returns(HelloResp) {
      option (api.get) = "/hello";
   }
   rpc Method2(OtherReq) returns(OtherResp) {
      option (api.post) = "/other";
   }
}

service NewService {
   rpc Method3(OtherReq) returns(OtherResp) {
      option (api.get) = "/new";
   }
}

  2. Switch to the directory where the new command was executed and update the modified IDL

    hz update -I idl -idl idl/hello/hello.proto

Note.

  • If the dependency of the IDL is not in the same path as the main IDL, you need to add the -I option, which means the path to search for the IDL, equivalent to the -I command of protoc.

  • When writing update command, you need to specify not only the IDL file that defines service, but also all the dependency files, because protobuf’s dependency files will not be updated automatically.

    1. As you can see

      Add new method under biz/handler/hello/hello_service.go; The file new_service.go and the corresponding “Method3” method have been added under biz/handler/hello.

      Now let’s develop the “Method2” interface:

      // Method2 .
// @router /other [POST]
func Method2(ctx context.Context, c *app.RequestContext) {
   var err error
   var req hello.OtherReq
   err = c.BindAndValidate(&req)
   if err != nil {
      c.String(400, err.Error())
      return
   }

   resp := new(hello.OtherResp)

   // added logic
   resp.Resp = "Other method: " + req.Other

   c.JSON(200, resp)
}

  1. Compile the project

    go build

  2. Run the project and test it

    Run the project:

    ./{{your binary}}

    Test：

    curl --location --request POST 'http://127.0.0.1:8888/other' \
--header 'Content-Type: application/json' \
--data-raw '{
    "Other": "other method"
}'

    If it returns {"Resp":"Other method: other method"}, it works.

For more example code, please refer to code.


Last modified January 18, 2024 : Upload volo blog (#936) (1fc8abb)