healthcheck一个不错的 Kubernetes liveness && readiness prob handler 实现

healthcheck 实现了一个开箱即用的Kubernetes liveness&& readiness prob 实现,我们可以直接拿来使用
已经包含了tcp,dns,http,Goroutine prob,同时也支持prometheus,还是很方便的
以下是一个简单的试用

参考代码

 
package main
import (
    "fmt"
    "log"
    "net/http"
    "net/http/httptest"
    "net/http/httputil"
    "os"
    "os/signal"
    "strings"
    "syscall"
    "time"
    "github.com/heptiolabs/healthcheck"
    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
)
func main() {
    registry := prometheus.NewRegistry()
    // Create a metrics-exposing Handler for the Prometheus registry
    // The healthcheck related metrics will be prefixed with the provided namespace
    health := healthcheck.NewMetricsHandler(registry, "example")
    // Create a Handler that we can use to register liveness and readiness checks.
    // Make sure we can connect to an upstream dependency over TCP in less than
    // 50ms. Run this check asynchronously in the background every 10 seconds
    // instead of every time the /ready or /live endpoints are hit.
    //
    // Async is useful whenever a check is expensive (especially if it causes
    // load on upstream services).
    // upstreamAddr := "upstream.example.com:5432"
    // health.AddReadinessCheck(
    //  "upstream-dep-tcp",
    //  healthcheck.Async(healthcheck.TCPDialCheck(upstreamAddr, 50*time.Millisecond), 10*time.Second))
    // Add a readiness check against the health of an upstream HTTP dependency
    upstreamURL := "https://www.cnblogs.com/rongfengliang"
    health.AddReadinessCheck(
        "upstream-dep-http",
        healthcheck.HTTPGetCheck(upstreamURL, 500*time.Millisecond))
    // Implement a custom check with a 50 millisecond timeout.
    health.AddLivenessCheck("custom-check-with-timeout", healthcheck.Timeout(func() error {
        // Simulate some work that could take a long time
        time.Sleep(time.Millisecond * 100)
        return nil
    }, 500*time.Millisecond))
    // Expose the readiness endpoints on a custom path /healthz mixed into
    // our main application mux.
    mux := http.NewServeMux()
    mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte("Hello, world!"))
    })
    mux.HandleFunc("/healthz", health.LiveEndpoint)
    mux.Handle("/metrics", promhttp.HandlerFor(registry, promhttp.HandlerOpts{}))
    // Sleep for just a moment to make sure our Async handler had a chance to run
    //time.Sleep(500 * time.Millisecond)
    go http.ListenAndServe("0.0.0.0:9402", mux)
    // Make a sample request to the /healthz endpoint and print the response.
    fmt.Println(dumpRequest(mux, "GET", "/healthz"))
    sigChan := make(chan os.Signal, 1)
    signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)
    sig := <-sigChan
    log.Printf("shutting down %v signal received", sig)
}
func dumpRequest(handler http.Handler, method string, path string) string {
    req, err := http.NewRequest(method, path, nil)
    if err != nil {
        panic(err)
    }
    rr := httptest.NewRecorder()
    handler.ServeHTTP(rr, req)
    dump, err := httputil.DumpResponse(rr.Result(), true)
    if err != nil {
        panic(err)
    }
    return strings.Replace(string(dump), "\r\n", "\n", -1)
}

参考效果

 

 

参考资料

https://github.com/heptiolabs/healthcheck
https://godoc.org/github.com/heptiolabs/healthcheck#Handler

posted on 2020-11-29 23:48  荣锋亮  阅读(221)  评论(0编辑  收藏  举报

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