first (BIG) commit

gotenberg.go

@@ -0,0 +1,86 @@
+/*
+Package main handles the application startup and shutdown.
+
+Gotenberg is a stateless API for generating PDF from many sources
+(".html", ".doc", ".docx").
+
+For more information, go to https://github.com/gulien/gotenberg.
+*/
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+	"os/signal"
+	"time"
+
+	"github.com/gulien/gotenberg/config"
+	"github.com/gulien/gotenberg/logger"
+	"github.com/gulien/gotenberg/middlewares"
+
+	"github.com/gorilla/mux"
+)
+
+// version will be set on build time.
+var version = "master"
+
+// init sets up the application configuration.
+func init() {
+	err := config.MakeConfig()
+	if err != nil {
+		logger.Log.Fatal(err)
+		os.Exit(1)
+	}
+
+	logger.SetLevel(config.AppConfig.LogLevel)
+	logger.Log.Infof("Gotenberg %s", version)
+}
+
+// main initializes the application and handles
+// graceful shutdown.
+func main() {
+	r := mux.NewRouter()
+
+	// defines our entry point.
+	r.Handle("/", middlewares.GetMiddlewaresChain()).Methods("POST")
+
+	srv := &http.Server{
+		Addr: fmt.Sprintf(":%s", config.AppConfig.Port),
+		// good practice to set timeouts to avoid Slowloris attacks.
+		WriteTimeout: time.Second * 15,
+		ReadTimeout:  time.Second * 15,
+		IdleTimeout:  time.Second * 60,
+		Handler:      middlewares.LoggingHandler(r),
+	}
+
+	// runs our server in a goroutine so that it doesn't block.
+	go func() {
+		logger.Log.Infof("Listening to port %s", config.AppConfig.Port)
+		if err := srv.ListenAndServe(); err != nil {
+			logger.Log.Panicf("Unrecoverable error: %s", err)
+			os.Exit(1)
+		}
+	}()
+
+	c := make(chan os.Signal, 1)
+	// we'll accept graceful shutdowns when quit via SIGINT (Ctrl+C)
+	// SIGKILL, SIGQUIT or SIGTERM (Ctrl+/) will not be caught.
+	signal.Notify(c, os.Interrupt)
+
+	// blocks until we receive our signal.
+	<-c
+
+	// creates a deadline to wait for.
+	var wait time.Duration
+	ctx, cancel := context.WithTimeout(context.Background(), wait)
+	defer cancel()
+
+	// doesn't block if no connections, but will otherwise wait
+	// until the timeout deadline.
+	srv.Shutdown(ctx)
+
+	logger.Log.Info("Bye!")
+	os.Exit(0)
+}