refac: rethought the complete workflow and deployement flow ; docs etc.

cmd/server/main.go

@@ -3,67 +3,139 @@ package main
 import (
 	"RenewCMS/api"
 	validator "RenewCMS/api/pkg/validator"
+	"context"
+	"errors"
 	"fmt"
+	"log"
 	"net/http"
 	"os"
+	"os/signal"
+	"syscall"
+	"time"
 
-	"github.com/go-chi/chi/v5"
 	"github.com/joho/godotenv"
 )
 
+var version = "dev"
+
+const (
+	readHeaderTimeout = 10 * time.Second
+	readTimeout       = 30 * time.Second
+	writeTimeout      = 60 * time.Second
+	idleTimeout       = 120 * time.Second
+	shutdownTimeout   = 10 * time.Second
+)
+
 var possibleEnvFileLocations = []string{".env", "../.env"}
-var envVarsToLoad = []string{
-	"HOST",
-	"PORT",
+
+var requiredEnvVars = []string{
+	"PUBLIC_URL",
 	"JWT_SECRET",
-	"ENVIRONMENT",
-	"CORS_ALLOWED_ORIGINS",
-	"DB_FILE",
-	"UPLOAD_DIR",
 	"SMTP_EMAIL",
 	"SMTP_PASSWORD",
 	"SMTP_HOST",
 	"SMTP_PORT",
 }
 
+var envDefaults = map[string]string{
+	"ENVIRONMENT": "production",
+	"PORT":        "8080",
+	"DB_FILE":     "./data/renewcms.db",
+	"UPLOAD_DIR":  "./data/uploads",
+}
+
+func main() {
+	if err := run(); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run() error {
+	initEnvVariables()
+
+	container, closeDb := api.InitContainer()
+	defer closeDatabase(closeDb)
+	validator.InitValidator()
+
+	server := newServer(api.InitRoutes(container))
+	return serveUntilStopped(server)
+}
+
 func initEnvVariables() {
-	var err error
+	loadEnvFile()
+	applyEnvDefaults()
+	ensureRequiredEnvVars()
+}
+
+func loadEnvFile() {
 	for _, envLocation := range possibleEnvFileLocations {
-		err = godotenv.Load(envLocation)
-		if err == nil {
-			break
+		if godotenv.Load(envLocation) == nil {
+			return
 		}
 	}
-	if err != nil {
-		fmt.Println("WARNING: Could not load any .env file")
-	}
+	log.Println("WARNING: Could not load any .env file")
+}
 
-	for _, envVar := range envVarsToLoad {
-		if _, ok := os.LookupEnv(envVar); !ok {
+func applyEnvDefaults() {
+	for envVar, value := range envDefaults {
+		if _, isSet := os.LookupEnv(envVar); !isSet {
+			_ = os.Setenv(envVar, value)
+		}
+	}
+}
+
+func ensureRequiredEnvVars() {
+	for _, envVar := range requiredEnvVars {
+		if _, isSet := os.LookupEnv(envVar); !isSet {
 			panic(fmt.Sprintf("Environment variable %s is not set", envVar))
 		}
 	}
 }
 
-func initServer() *chi.Mux {
-	initEnvVariables()
-
-	container := api.InitContainer()
-	validator.InitValidator()
-
-	return api.InitRoutes(container)
-}
-
-func startServer(router *chi.Mux) error {
-	fmt.Println("Server starting on http://" + os.Getenv("HOST"))
-	err := http.ListenAndServe(":"+os.Getenv("PORT"), router)
-	return err
-}
-
-func main() {
-	router := initServer()
-	err := startServer(router)
-	if err != nil {
-		panic(err)
+func closeDatabase(closeDb func() error) {
+	if err := closeDb(); err != nil {
+		log.Println("error closing database:", err)
 	}
 }
+
+func newServer(handler http.Handler) *http.Server {
+	return &http.Server{
+		Addr:              ":" + os.Getenv("PORT"),
+		Handler:           handler,
+		ReadHeaderTimeout: readHeaderTimeout,
+		ReadTimeout:       readTimeout,
+		WriteTimeout:      writeTimeout,
+		IdleTimeout:       idleTimeout,
+	}
+}
+
+func serveUntilStopped(server *http.Server) error {
+	stopSignal, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	serverErr := make(chan error, 1)
+	go listen(server, serverErr)
+
+	select {
+	case err := <-serverErr:
+		return err
+	case <-stopSignal.Done():
+		return shutdown(server)
+	}
+}
+
+func listen(server *http.Server, serverErr chan<- error) {
+	log.Printf("RenewCMS %s (%s) listening on %s, public URL %s", version, os.Getenv("ENVIRONMENT"), server.Addr, os.Getenv("PUBLIC_URL"))
+	err := server.ListenAndServe()
+	if errors.Is(err, http.ErrServerClosed) {
+		err = nil
+	}
+	serverErr <- err
+}
+
+func shutdown(server *http.Server) error {
+	log.Println("shutting down...")
+	ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
+	defer cancel()
+	return server.Shutdown(ctx)
+}