Last active
July 18, 2019 04:06
-
-
Save 0sc/0a28b9c7cd8aec4b74bcdf44b74d4125 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
package main | |
import ( | |
"fmt" | |
"io" | |
"log" | |
"math" | |
"math/rand" | |
"net/http" | |
"os" | |
"strings" | |
"time" | |
"github.com/prometheus/client_golang/prometheus" | |
"github.com/prometheus/client_golang/prometheus/promhttp" | |
) | |
var ( | |
requestCounter = prometheus.NewCounterVec( | |
prometheus.CounterOpts{ | |
Namespace: "app", | |
Name: "http_requests_total", | |
Help: "count http responses", | |
}, | |
[]string{"code", "method"}, | |
) | |
responseCounter = prometheus.NewCounterVec( | |
prometheus.CounterOpts{ | |
Namespace: "app", | |
Name: "http_response_total", | |
Help: "count http requests", | |
}, | |
[]string{"status", "code"}, | |
) | |
hello = map[string]string{ | |
"en": "Hello", | |
"es": "Hola", | |
"de": "Hallo", | |
"ch": "你好", | |
"ru": "Привет", | |
"fr": "Bonjour", | |
} | |
port = os.Getenv("PORT") | |
) | |
func handler(w http.ResponseWriter, r *http.Request) { | |
lang := strings.TrimPrefix(r.URL.RequestURI(), "/") | |
greeting, ok := hello[lang] | |
if !ok { | |
fmt.Printf("unknown language: %s\n", lang) | |
w.WriteHeader(http.StatusBadRequest) | |
return | |
} | |
w.WriteHeader(http.StatusOK) | |
fmt.Fprint(w, greeting) | |
} | |
func selfPing() { | |
start := time.Now() | |
oscillationFactor := func() float64 { | |
return 20 + math.Sin(math.Sin(2*math.Pi*float64(time.Since(start))/float64(10*time.Minute))) | |
} | |
langs := []string{"en", "es", "de", "ch", "ru", "fra"} | |
for { | |
time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond) | |
index := rand.Intn(len(langs)) | |
lang := langs[index] | |
resp, err := http.Get(fmt.Sprintf("http://0.0.0.0:%s/%s", port, lang)) | |
kind := "failure" | |
if err != nil { | |
log.Println("got error", err) | |
responseCounter.WithLabelValues(kind, "").Inc() | |
continue | |
} | |
if resp.StatusCode == http.StatusOK { | |
kind = "success" | |
} | |
io.Copy(os.Stdout, resp.Body) | |
fmt.Println() | |
resp.Body.Close() | |
responseCounter.WithLabelValues(kind, resp.Status).Inc() | |
} | |
} | |
func main() { | |
rand.Seed(time.Now().Unix()) | |
pr := prometheus.NewRegistry() | |
pr.MustRegister(requestCounter, responseCounter) | |
mux := http.NewServeMux() | |
mux.Handle("/metrics", promhttp.HandlerFor(pr, promhttp.HandlerOpts{})) | |
mux.Handle("/", promhttp.InstrumentHandlerCounter(requestCounter, http.HandlerFunc(handler))) | |
addr := fmt.Sprintf("0.0.0.0:%s", port) | |
log.Println("starting server on", addr) | |
go selfPing() | |
log.Fatal(http.ListenAndServe(addr, mux)) | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment