gRPC: Error handling: Richer error model

gRPC 的错误处理用起来不是很方便。一个 RPC 返回的错误，有时是不能展示给用户的，有时又需要展示给用户，区分起来太麻烦了。可以考虑给 Status 额外添加 error details。

package status_test

import (
    "fmt"

    "google.golang.org/genproto/googleapis/rpc/errdetails"
    "google.golang.org/grpc/codes"
    "google.golang.org/grpc/status"
)

func ExampleWithDetail() {
    s := status.New(codes.ResourceExhausted, "a per-user quota has been exhausted")

    var err error
    s, err = s.WithDetails(
        &errdetails.LocalizedMessage{
            Locale:  "zh-CN",
            Message: "您已领取，下次再来吧",
        },
        &errdetails.Help{
            Links: []*errdetails.Help_Link{
                {
                    Description: "gPRC - Richer error model",
                    Url:         "https://grpc.io/docs/guides/error/#richer-error-model",
                },
                {
                    Description: "googleapis - Error Model",
                    Url:         "https://cloud.google.com/apis/design/errors#error_model",
                },
                {
                    Description: "googleapis - google.rpc.Status",
                    Url:         "https://github.com/googleapis/googleapis/blob/master/google/rpc/status.proto",
                },
                {
                    Description: "googleapis - google.rpc.error_details",
                    Url:         "https://github.com/googleapis/googleapis/blob/master/google/rpc/error_details.proto",
                },
                {
                    Description: "google.golang.org/grpc/status",
                    Url:         "https://pkg.go.dev/google.golang.org/grpc@v1.54.0/status",
                },
                {
                    Description: "google.golang.org/genproto/googleapis/rpc/errdetails",
                    Url:         "https://pkg.go.dev/google.golang.org/genproto/googleapis/rpc/errdetails",
                },
            },
        },
    )
    if err != nil {
        panic(err)
    }

        // return error
        // s.Err() returns an error

    for _, detail := range s.Details() {
        switch detail := detail.(type) {
        case *errdetails.LocalizedMessage:
            fmt.Println(detail.GetLocale(), detail.GetMessage())
        case *errdetails.Help:
            for _, link := range detail.GetLinks() {
                fmt.Println(link.GetDescription())
                fmt.Println(link.GetUrl())
            }
        }
    }

    // Output:
    // zh-CN 您已领取，下次再来吧
    // gPRC - Richer error model
    // https://grpc.io/docs/guides/error/#richer-error-model
    // googleapis - Error Model
    // https://cloud.google.com/apis/design/errors#error_model
    // googleapis - google.rpc.Status
    // https://github.com/googleapis/googleapis/blob/master/google/rpc/status.proto
    // googleapis - google.rpc.error_details
    // https://github.com/googleapis/googleapis/blob/master/google/rpc/error_details.proto
    // google.golang.org/grpc/status
    // https://pkg.go.dev/google.golang.org/grpc@v1.54.0/status
    // google.golang.org/genproto/googleapis/rpc/errdetails
    // https://pkg.go.dev/google.golang.org/genproto/googleapis/rpc/errdetails
}

dushaoshuai / dushaoshuai.github.io

gRPC: Error handling: Richer error model #46