通过Golang微服务开发可以实现哪些功能？

// 服务A
package serviceA

import "github.com/gin-gonic/gin"

func main() {
    router := gin.Default()
    router.GET("/serviceA", func(c *gin.Context) {
        c.JSON(200, gin.H{
            "message": "Hello from service A",
        })
    })
    router.Run(":8080")
}

// 服务B
package serviceB

import "github.com/gin-gonic/gin"

func main() {
    router := gin.Default()
    router.GET("/serviceB", func(c *gin.Context) {
        c.JSON(200, gin.H{
            "message": "Hello from service B",
        })
    })
    router.Run(":8081")
}

package main

import (
    "fmt"
    "net/http"
)

func main() {
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprint(w, "Hello from Golang!")
    })
    http.ListenAndServe(":8080", nil)
}

package main

import (
    "github.com/afex/hystrix-go/hystrix"
    "github.com/gin-gonic/gin"
    "net/http"
    "time"
)

func main() {
    router := gin.Default()

    // 设置断路器
    hystrix.ConfigureCommand("my_command", hystrix.CommandConfig{
        Timeout:               1000,
        MaxConcurrentRequests:  20,
        ErrorPercentThreshold:  50,
        RequestVolumeThreshold: 5,
        SleepWindow:            5000,
    })

    router.GET("/", func(c *gin.Context) {
        result := make(chan string, 1)
        // 使用断路器包装请求
        hystrix.Go("my_command", func() error {
            // 请求服务C
            resp, err := http.Get("http://localhost:8082/serviceC")
            if err != nil {
                return err
            }

            defer resp.Body.Close()

            // 读取响应
            body, err := ioutil.ReadAll(resp.Body)
            if err != nil {
                return err
            }

            result <- string(body)
            return nil
        }, func(err error) error {
            // 处理错误
            result <- err.Error()
            return nil
        })

        select {
        case r := <-result:
            c.JSON(http.StatusOK, gin.H{
                "message": r,
            })
        case <-time.After(2000 * time.Millisecond):
            c.JSON(http.StatusInternalServerError, gin.H{
                "message": "Request timed out",
            })
        }
    })

    router.Run(":8081")
}

package main

import (
    "github.com/gin-gonic/gin"
    "net/http"
)

func main() {
    router := gin.Default()
    router.GET("/", func(c *gin.Context) {
        c.JSON(200, gin.H{
            "message": "Hello from service A",
        })
    })
    router.Run(":8080")
}

// Dockerfile
FROM golang:1.16-alpine
WORKDIR /app
COPY . .
RUN go build -o main .
EXPOSE 8080
CMD ["./main"]