go-micro微服务教程四：实现用户信息微服务的api

本节课的主要目的是实现用户api srevices层和micro api网关，获取本节代码

micro new 指令生成 api 骨架代码

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cd micro-examples/part2
micro new user/api --type=api --alias=user --namespace=io.github.entere --gopath=false

修改生成原型

修改 proto/user/user.proto 为以下内容

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syntax = "proto3";

package io.github.entere.api.user;

import "github.com/micro/go-micro/api/proto/api.proto";

service User {
    rpc Info(go.api.Request) returns (go.api.Response) {}
}

编译生成原型

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cd user/api
protoc --proto_path=${GOPATH}/src:. --micro_out=. --go_out=. proto/user/user.proto

修改 client/user.go

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package client

import (
    "context"

    user "github.com/entere/micro-examples/part2/user/srv/proto/user"
    "github.com/micro/go-micro"
    "github.com/micro/go-micro/server"
)

type userKey struct{}

// FromContext retrieves the client from the Context
func UserFromContext(ctx context.Context) (user.UserService, bool) {
    c, ok := ctx.Value(userKey{}).(user.UserService)
    return c, ok
}

// Client returns a wrapper for the UserClient
func UserWrapper(service micro.Service) server.HandlerWrapper {
    client := user.NewUserService("io.github.entere.srv.user", service.Client())

    return func(fn server.HandlerFunc) server.HandlerFunc {
        return func(ctx context.Context, req server.Request, rsp interface{}) error {
            ctx = context.WithValue(ctx, userKey{}, client)
            return fn(ctx, req, rsp)
        }
    }
}

修改 handler/user.go

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package handler

import (
    "context"
    "encoding/json"
    "github.com/micro/go-micro/util/log"

    "github.com/entere/micro-examples/part2/user/api/client"
    userSrv "github.com/entere/micro-examples/part2/user/srv/proto/user"
    api "github.com/micro/go-micro/api/proto"
    "github.com/micro/go-micro/errors"
)

type User struct{}

func extractValue(pair *api.Pair) string {
    if pair == nil {
        return ""
    }
    if len(pair.Values) == 0 {
        return ""
    }
    return pair.Values[0]
}

// User.Info is called by the API as /user/call with post body {"name": "foo"}
func (e *User) Info(ctx context.Context, req *api.Request, rsp *api.Response) error {
    log.Log("Received User.Info request")

    // extract the client from the context
    userClient, ok := client.UserFromContext(ctx)
    if !ok {
        return errors.InternalServerError("io.github.entere.api.user.info", "user client not found")
    }

    // make request
    response, err := userClient.QueryUserByID(ctx, &userSrv.QueryRequest{
        UserId: extractValue(req.Post["user_id"]),
    })
    if err != nil {
        return errors.InternalServerError("io.github.entere.api.user.user.call", err.Error())
    }

    b, _ := json.Marshal(response)

    rsp.StatusCode = 200
    rsp.Body = string(b)

    return nil
}

修改 main.go

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package main

import (
    "github.com/micro/go-micro/util/log"

    "github.com/entere/micro-examples/part2/user/api/client"
    "github.com/entere/micro-examples/part2/user/api/handler"
    "github.com/micro/go-micro"

    user "github.com/entere/micro-examples/part2/user/api/proto/user"
)

func main() {
    // New Service
    service := micro.NewService(
        micro.Name("io.github.entere.api.user"),
        micro.Version("latest"),
    )

    // Initialise service
    service.Init(
        // create wrap for the User srv client
        micro.WrapHandler(client.UserWrapper(service)),
    )

    // Register Handler
    user.RegisterUserHandler(service.Server(), new(handler.User))

    // Run service
    if err := service.Run(); err != nil {
        log.Fatal(err)
    }
}

编译运行

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cd usr/api
make build
./user-api

启动micro api 网关

重新运行 srv api 并启动 micro api， 程序调用顺序：micro api->api->srv

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# 启动 srv
cd micro-examples/part2/user/srv
./user-srv

#启动 api
cd micro-examples/part2/user/api
./user-api

#启动 micro-api api网关，实现restful api接口支持
cd micro-examples/
micro api --namespace=io.github.entere.api --handler=api

测试

curl 请求接口：

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curl -H "Content-Type:application/x-www-form-urlencoded" -X POST -d "user_id=f546e78a46284765" http://localhost:8080/user/info

返回结果：

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{
    "code": 200,
    "data": {
        "user_id": "f546e78a46284765",
        "nickname": "匿名",
        "mobile": "138********",
        "avatar_url": "avatar.jpg",
        "gender": 1
    }
}