InVisionApp/go-health

package main

import (
    "log"
    "net/http"
    "os"
    "sync"
)

// mischief
type loki struct {
    sync.Mutex
    callcount int
}

// this is just a function that will return true
// the last 5 out of every 15 times called
func (l *loki) shouldBreakThings() bool {
    l.Lock()
    defer l.Unlock()
    l.callcount++
    if l.callcount > 15 {
        l.callcount = 0
        return false
    }
    if l.callcount > 10 {
        return true
    }

    return false
}

var (
    l      *loki
    logger *log.Logger
)

func init() {
    l = &loki{}
    logger = log.New(os.Stderr, "dependency: ", 0)
}

func handleRequest(rw http.ResponseWriter, r *http.Request) {
    // ignore favicon
    if r.URL.Path == "/favicon.ico" {
        rw.WriteHeader(http.StatusOK)
        return
    }
    if l.shouldBreakThings() {
        logger.Print("👎")
        rw.WriteHeader(http.StatusInternalServerError)
        return
    }
    logger.Print("👍")
    rw.WriteHeader(http.StatusOK)
    return
}

func main() {
    http.HandleFunc("/", handleRequest)
    http.ListenAndServe("0.0.0.0:8081", nil)
}