refactoring of main

Author: avoidik

cmd/web/app.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"net/http"
+
 	"github.com/alexedwards/scs"
 	"snippetbox.org/pkg/models"
 )
@@ -11,6 +13,9 @@ type App struct {
 	staticDir    string
 	databaseFile string
 	secret       string
+	tlsCert      string
+	tlsKey       string
+	server       *http.Server
 	sessions     *scs.Manager
 	database     *models.Database
 }

cmd/web/main.go

@@ -1,24 +1,18 @@
 package main
 
 import (
-	"context"
-	"database/sql"
 	"flag"
-	"fmt"
 	"log"
-	"net/http"
 	"os"
-	"os/signal"
 	"time"
 
 	"github.com/alexedwards/scs"
 
 	_ "github.com/mattn/go-sqlite3"
-	"snippetbox.org/pkg/models"
 )
 
-func existDir(path string) bool {
-	if _, err := os.Stat(path); os.IsNotExist(err) {
+func existDir(path *string) bool {
+	if _, err := os.Stat(*path); os.IsNotExist(err) {
 		return false
 	}
 	return true
@@ -33,105 +27,40 @@ func main() {
 	flag.StringVar(&app.htmlDir, "html-dir", "./ui/html", "Path to html templates")
 	flag.StringVar(&app.databaseFile, "db-file", "./info.db", "Path to database file")
 	flag.StringVar(&app.secret, "secret", "8sB9ozuKkqWtN3b6lEiInd1dSISxPWogpaGV5HG4wKs=", "Secret key for cookies encryption")
-	tlsCert := flag.String("tls-cert", "./tls/cert.pem", "TLS certificate")
-	tlsKey := flag.String("tls-key", "./tls/key.pem", "TLS private-key")
+	flag.StringVar(&app.tlsCert, "tls-cert", "./tls/cert.pem", "TLS certificate")
+	flag.StringVar(&app.tlsKey, "tls-key", "./tls/key.pem", "TLS private-key")
 	flag.Parse()
 
-	if !existDir(app.staticDir) {
+	if !existDir(&app.staticDir) {
 		log.Fatal("Folder for static-dir was not found")
 	}
 
-	if !existDir(app.htmlDir) {
+	if !existDir(&app.htmlDir) {
 		log.Fatal("Folder for html-dir was not found")
 	}
 
-	if !existDir(*tlsCert) {
+	if !existDir(&app.tlsCert) {
 		log.Fatal("TLS certificate was not found")
 	}
 
-	if !existDir(*tlsKey) {
+	if !existDir(&app.tlsKey) {
 		log.Fatal("TLS key was not found")
 	}
 
-	if err := app.connectDb(); err != nil {
+	if err := app.ConnectDb(); err != nil {
 		log.Fatal("Failed to establish database connection")
 	}
-	defer func() {
-		log.Println("Closing database connection")
-		app.closeDB()
-	}()
+	defer app.CloseDB()
 
 	sessionManager := scs.NewCookieManager(app.secret)
 	sessionManager.Lifetime(12 * time.Hour)
 	sessionManager.Persist(true)
 	sessionManager.Secure(true)
 	app.sessions = sessionManager
 
-	server := &http.Server{
-		Addr:         app.addr,
-		Handler:      app.Routes(),
-		WriteTimeout: 15 * time.Second,
-		ReadTimeout:  15 * time.Second,
-		IdleTimeout:  60 * time.Second,
-	}
-
-	c := make(chan os.Signal, 1)
-	signal.Notify(c, os.Interrupt)
-	go func() {
-		for sig := range c {
-			log.Printf("Terminating (signal caught - %s)\n", sig)
-			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-			defer func() {
-				log.Println("Closing context")
-				cancel()
-			}()
-			server.Shutdown(ctx)
-		}
-	}()
-
-	log.Printf("Listening on %s\n", app.addr)
-
-	if err := server.ListenAndServeTLS(*tlsCert, *tlsKey); err != nil {
-		if err != http.ErrServerClosed {
-			log.Println("The error below raised after shutdown:")
-			log.Println(err)
-		}
-	}
-}
-
-func (app *App) connectDb() error {
-	initDb := !existDir(app.databaseFile)
-
-	dsn := fmt.Sprintf("file:%s?cache=shared&_loc=auto", app.databaseFile)
-	db, err := sql.Open("sqlite3", dsn)
-	if err != nil {
-		return err
-	}
+	app.InitServer()
 
-	defer func() {
-		if err != nil {
-			db.Close()
-		}
-	}()
+	app.MonitorInterrupts()
 
-	if err = db.Ping(); err != nil {
-		return err
-	}
-
-	app.database = &models.Database{DB: db}
-
-	if initDb {
-		log.Println("Initializing database...")
-		if err := app.database.InitializeDb(); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (app *App) closeDB() {
-	if app.database != nil {
-		app.database.Close()
-	}
+	app.RunServer()
 }

cmd/web/server.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"time"
+
+	"snippetbox.org/pkg/models"
+)
+
+func (app *App) MonitorInterrupts() {
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	go func() {
+		for sig := range c {
+			log.Printf("Terminating (signal caught - %s)\n", sig)
+			ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+			defer func() {
+				log.Println("Closing context")
+				cancel()
+			}()
+			app.server.Shutdown(ctx)
+		}
+	}()
+}
+
+func (app *App) ConnectDb() error {
+	initDb := !existDir(&app.databaseFile)
+
+	dsn := fmt.Sprintf("file:%s?cache=shared&_loc=auto", app.databaseFile)
+	db, err := sql.Open("sqlite3", dsn)
+	if err != nil {
+		return err
+	}
+
+	defer func() {
+		if err != nil {
+			db.Close()
+		}
+	}()
+
+	if err = db.Ping(); err != nil {
+		return err
+	}
+
+	app.database = &models.Database{DB: db}
+
+	if initDb {
+		log.Println("Initializing database...")
+		if err := app.database.InitializeDb(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (app *App) CloseDB() {
+	log.Println("Closing database connection")
+	if app.database != nil {
+		app.database.Close()
+	}
+}
+
+func (app *App) InitServer() {
+	app.server = &http.Server{
+		Addr:         app.addr,
+		Handler:      app.Routes(),
+		WriteTimeout: 15 * time.Second,
+		ReadTimeout:  15 * time.Second,
+		IdleTimeout:  60 * time.Second,
+	}
+}
+
+func (app *App) RunServer() {
+	log.Printf("Listening on %s\n", app.addr)
+
+	if err := app.server.ListenAndServeTLS(app.tlsCert, app.tlsKey); err != nil {
+		if err != http.ErrServerClosed {
+			log.Println("The error below raised after shutdown:")
+			log.Println(err)
+		}
+	}
+}