FAQ

1. google/protobuf/descriptor.proto: File not found. error while using kratos proto command.

This issue is mainly caused by the improperly installation of protoc. The documentation protoc-installation shows the correct way to install protoc. It is highly recommended that install protoc by system package manager to ensure the installation’s integrity. If you have to install the pre-compiled version, please refer to the readme.txt in the zip file, make sure all the files under include folder could be put to correct include path of your system, e.g. /usr/local/include/, so that protoc can find them while compiling.

2. There are errors from IDE show import "google/api/annotations.proto"; with red wavy line

You can append thrid_party directory to custom protobuf`s include paths. Please follow these doc:

• GoLand
• VSCode

3. Develop with goland

All you need to do is configurate some setting like this:

4. The code newly generated after the new release is unavailable, with system alarming errors.

You can try to follow this:

1. kratos upgrade
2. Modify the version of kratos in go.mod file
3. go generate ./…

5. After invoke kratos client, there are no deserved http file.

You can run make http or kratos client xxx --go-http_opt=omitempty=false

6. It show Command not found: kratos after installed Kratos

Make sure the env value PATH contain GOBIN directory. Or you can invoke kratos inside GOBIN directory.

7. It show some proto file not found when generate pb file.

Copy the missing proto file to third_party directory. Or append missing proto file location to corresponding Makefile command.

8.There are // no validation rules for xxxx for configurated property.

git clone github.com/envoyproxy/protoc-gen-validate
cd protoc-gen-validate
make build

9. Custom Http return value

You can write a custom ResponseEncoder and set to http.Server() by using http.ResponseEncoder()

10. How to control the http return field 0 value ignore field and use proto’s message field as the http return field

You can import it in the main.go of the http service

import (
  "github.com/go-kratos/kratos/v2/encoding/json"
  "google.golang.org/protobuf/encoding/protojson"
)

Set json.MarshalOptions in the init method

func init() {
    flag.StringVar(&flagconf, "conf", "../../configs", "config path, eg: -conf config.yaml")
    //Add this code
    json.MarshalOptions = protojson.MarshalOptions{
        EmitUnpopulated: true, //Default value not ignored
        UseProtoNames:   true, //Use proto name to return http field
    }
}

11、Controls the name and number of the enum (enumeration type) returned by http

You can import it in the main.go of the http service

import (
  "github.com/go-kratos/kratos/v2/encoding/json"
  "google.golang.org/protobuf/encoding/protojson"
)

Set json.MarshalOptions in the init method

func init() {
    flag.StringVar(&flagconf, "conf", "../../configs", "config path, eg: -conf config.yaml")
    // Add this code
    json.MarshalOptions = protojson.MarshalOptions{
        UseEnumNumbers: true, // UseEnumNumbers emits enum values as numbers.
    }
}

For more control over http return content, please refer to the documentation: https://pkg.go.dev/google.golang.org/protobuf@v1.30.0/encoding/protojson#MarshalOptions