signoz

package main

import (
	"bytes"
	"context"
	"encoding/json"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gorilla/mux"
	"gopkg.in/natefinch/lumberjack.v2"
)

type SignozAlertResPayload struct {
	Channel     string `json:"channel"`
	Attachments []struct {
		Title      string   `json:"title"`
		Text       string   `json:"text"`
		Fallback   string   `json:"fallback"`
		CallbackID string   `json:"callback_id"`
		Footer     string   `json:"footer"`
		MrkdwnIn   []string `json:"mrkdwn_in"`
	} `json:"attachments"`
}

func handler(w http.ResponseWriter, r *http.Request) {

	webhook_url := os.Getenv("SQUADCAST_WEBHOOK_URL")
	decoder := json.NewDecoder(r.Body)
	var sp SignozAlertResPayload
	err := decoder.Decode(&sp)
	if err != nil {
		panic(err)
	}
	for _, alert := range sp.Attachments {
		createIncident(webhook_url, alert.Title, alert.Text)
	}

}

func main() {

	r := mux.NewRouter()
	r.HandleFunc("/", handler)

	srv := &http.Server{
		Handler:      r,
		Addr:         ":80",
		ReadTimeout:  10 * time.Second,
		WriteTimeout: 10 * time.Second,
	}

	// Configure Logging
	LOG_FILE_LOCATION := os.Getenv("LOG_FILE_LOCATION")
	if LOG_FILE_LOCATION != "" {
		log.SetOutput(&lumberjack.Logger{
			Filename:   LOG_FILE_LOCATION,
			MaxSize:    500, // megabytes
			MaxBackups: 3,
			MaxAge:     28,   //days
			Compress:   true, // disabled by default
		})
	}

	// Start Server
	go func() {
		log.Println("Starting Server..")
		if err := srv.ListenAndServe(); err != nil {
			log.Fatal(err)
		}
	}()

	// Graceful Shutdown
	waitForShutdown(srv)
}

func waitForShutdown(srv *http.Server) {
	interruptChan := make(chan os.Signal, 1)
	signal.Notify(interruptChan, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)

	// Block until we receive our signal.
	<-interruptChan

	// Create a deadline to wait for.
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
	defer cancel()
	srv.Shutdown(ctx)

	log.Println("Shutting down")
	os.Exit(0)
}

// createIncident creates the incident in Squadcast with Signoz payload
func createIncident(webhook_url, title, description string) {
	postBody, _ := json.Marshal(map[string]string{
		"message":     title,
		"description": description,
	})

	resp, err := http.Post(webhook_url, "application/json",
		bytes.NewBuffer(postBody))

	if err != nil {
		log.Fatalf("An Error Occured %v", err)
	}
	defer resp.Body.Close()
}