简单API服务器功能

实现外部请求对API 服务器健康检查和状态查询，返回响应结果

1.API服务器的状态监测

以内存状态检测为例，获取当前服务器的健康状况、服务器硬盘、CPU 和内存使用量

func RAMCheck(c *gin.Context) {u, _ := mem.VirtualMemory()//获取当前内存占用量usedMB := int(u.Used) / MBusedGB := int(u.Used) / GBtotalMB := int(u.Total) / MBtotalGB := int(u.Total) / GBusedPercent := int(u.UsedPercent)status := http.StatusOKtext := "OK"//根据当前内存状态，返回健康信息if usedPercent >= 95 {status = http.StatusInternalServerErrortext = "CRITICAL"} else if usedPercent >= 90 {status = http.StatusTooManyRequeststext = "WARNING"}message := fmt.Sprintf("%s - Free space: %dMB (%dGB) / %dMB (%dGB) | Used: %d%%", text, usedMB, usedGB, totalMB, totalGB, usedPercent)c.String(status, "\n"+message)
}

2.加载路由

该代码块定义了一个叫 sd 的分组，在该分组下注册了 /health、/disk、/cpu、/ram HTTP 路径，分别路由到 sd.HealthCheck、sd.DiskCheck、sd.CPUCheck、sd.RAMCheck 函数。sd 分组主要用来检查 API Server 的状态：健康状况、服务器硬盘、CPU 和内存使用量

// Load loads the middlewares, routes, handlers.
func Load(g *gin.Engine, mw ...gin.HandlerFunc) *gin.Engine {// Middlewares.//设置响应头g.Use(gin.Recovery())g.Use(middleware.NoCache)g.Use(middleware.Options)g.Use(middleware.Secure)g.Use(mw...)// 404 Handler.//404设置g.NoRoute(func(c *gin.Context) {c.String(http.StatusNotFound, "The incorrect API route.")})// The health check handlerssvcd := g.Group("/sd"){svcd.GET("/health", sd.HealthCheck)svcd.GET("/disk", sd.DiskCheck)svcd.GET("/cpu", sd.CPUCheck)svcd.GET("/ram", sd.RAMCheck)}return g
}

3.程序入口

程序入口先进行路由的加载，随后在 apiserver 中也添加自检程序，在启动 HTTP 端口前 go 一个 pingServer 协程，启动 HTTP 端口后，该协程不断地 ping /sd/health 路径，如果失败次数超过一定次数，则终止 HTTP 服务器进程。通过自检可以最大程度地保证启动后的 API 服务器处于健康状态。

func main() {// Create the Gin engine.g := gin.New()middlewares := []gin.HandlerFunc{}// Routes.router.Load(// Cores.g,// Middlwares.middlewares...,)// Ping the server to make sure the router is working.go func() {if err := pingServer(); err != nil {log.Fatal("The router has no response, or it might took too long to start up.", err)}log.Print("The router has been deployed successfully.")}()log.Printf("Start to listening the incoming requests on http address: %s", ":8080")log.Printf(http.ListenAndServe(":8080", g).Error())
}// pingServer pings the http server to make sure the router is working.
func pingServer() error {for i := 0; i < 2; i++ {// Ping the server by sending a GET request to `/health`.resp, err := http.Get("http://127.0.0.1:8080" + "/sd/health")if err == nil && resp.StatusCode == 200 {return nil}// Sleep for a second to continue the next ping.log.Print("Waiting for the router, retry in 1 second.")time.Sleep(time.Second)}return errors.New("Cannot connect to the router.")
}