Refactor: Centralize App Startup and Config Loading (#33)

Reviewed-on: #33

internal/bootstrap/bootstrap.go

@@ -0,0 +1,97 @@
+package bootstrap
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"git.fossy.my.id/bagas/tunnel-please-controller/internal/config"
+	"git.fossy.my.id/bagas/tunnel-please-controller/internal/db/sqlc/repository"
+	"git.fossy.my.id/bagas/tunnel-please-controller/internal/server"
+	"github.com/jackc/pgx/v5"
+	"github.com/lestrrat-go/httprc/v3"
+	"github.com/lestrrat-go/jwx/v3/jwk"
+)
+
+type bootstrap struct {
+	config     config.Config
+	errChan    chan error
+	signalChan chan os.Signal
+}
+
+type Bootstrap interface {
+	Run() error
+}
+
+func New(config config.Config) Bootstrap {
+	errChan := make(chan error, 5)
+	signalChan := make(chan os.Signal, 1)
+	return &bootstrap{
+		config:     config,
+		errChan:    errChan,
+		signalChan: signalChan,
+	}
+}
+
+func (b *bootstrap) Run() error {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	signal.Notify(b.signalChan, os.Interrupt, syscall.SIGTERM)
+
+	dbURL := b.config.DatabaseURL()
+	repo, err := startDatabase(ctx, dbURL)
+	if err != nil {
+		return err
+	}
+
+	client := httprc.NewClient()
+	jwkCache, err := jwk.NewCache(ctx, client)
+	if err != nil {
+		return err
+	}
+	s := server.New(repo, jwkCache, b.config)
+
+	b.errChan = make(chan error, 2)
+
+	go func() {
+		if err = s.StartAPI(ctx, b.config.ApiAddr()); err != nil && !errors.Is(err, context.Canceled) {
+			b.errChan <- err
+		}
+	}()
+
+	go func() {
+		if err = s.StartController(ctx, b.config.ControllerAddr()); err != nil && !errors.Is(err, context.Canceled) {
+			b.errChan <- err
+		}
+	}()
+
+	select {
+	case err = <-b.errChan:
+		return fmt.Errorf("service error: %w", err)
+	case sig := <-b.signalChan:
+		log.Printf("Received signal %s, initiating graceful shutdown", sig)
+		cancel()
+		return nil
+	}
+}
+
+func startDatabase(ctx context.Context, dbURL string) (*repository.Queries, error) {
+	connect, err := pgx.Connect(ctx, dbURL)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func(connect *pgx.Conn, ctx context.Context) {
+		err = connect.Close(ctx)
+		if err != nil {
+			panic(err)
+		}
+	}(connect, ctx)
+
+	return repository.New(connect), nil
+}

internal/config/config.go

@@ -1,8 +1,81 @@
 package config
 
-import "os"
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"log"
+	"os"
 
-func Getenv(key, defaultValue string) string {
+	"github.com/joho/godotenv"
+)
+
+type config struct {
+	databaseUrl    string
+	controllerAddr string
+	apiAddr        string
+	authToken      string
+	jwksUrl        string
+}
+
+type Config interface {
+	DatabaseURL() string
+	ControllerAddr() string
+	ApiAddr() string
+	AuthToken() string
+	JwksURL() string
+}
+
+func (c *config) DatabaseURL() string    { return c.databaseUrl }
+func (c *config) ControllerAddr() string { return c.controllerAddr }
+func (c *config) ApiAddr() string        { return c.apiAddr }
+func (c *config) AuthToken() string      { return c.authToken }
+func (c *config) JwksURL() string        { return c.jwksUrl }
+
+func MustLoad() (Config, error) {
+	if err := loadEnvFile(); err != nil {
+		return nil, err
+	}
+
+	cfg, err := parse()
+	if err != nil {
+		return nil, err
+	}
+
+	return cfg, nil
+}
+
+func loadEnvFile() error {
+	if _, err := os.Stat(".env"); err == nil {
+		return godotenv.Load(".env")
+	}
+	return nil
+}
+
+func parse() (*config, error) {
+	databaseUrl := getenv("DATABASE_URL", "")
+	if databaseUrl == "" {
+		return nil, errors.New("DATABASE_URL environment variable not set")
+	}
+	controllerAddr := getenv("CONTROLLER_ADDR", ":8080")
+	apiAddr := getenv("API_ADDR", ":8081")
+	authToken := getenv("AUTH_TOKEN", "")
+	if authToken == "" {
+		authToken = generateAuthToken()
+		log.Printf("No AUTH_TOKEN provided. Generated token: %s", authToken)
+	}
+	jwksUrl := getenv("JWKS_URL", "")
+
+	return &config{
+		databaseUrl:    databaseUrl,
+		controllerAddr: controllerAddr,
+		apiAddr:        apiAddr,
+		authToken:      authToken,
+		jwksUrl:        jwksUrl,
+	}, nil
+}
+
+func getenv(key, defaultValue string) string {
 	val := os.Getenv(key)
 	if val == "" {
 		val = defaultValue
@@ -10,3 +83,11 @@ func Getenv(key, defaultValue string) string {
 
 	return val
 }
+
+func generateAuthToken() string {
+	buf := make([]byte, 32)
+	if _, err := rand.Read(buf); err != nil {
+		panic(err)
+	}
+	return base64.StdEncoding.EncodeToString(buf)
+}

internal/server/server.go

@@ -12,8 +12,8 @@ import (
 	"sync"
 	"time"
 
-	"git.fossy.my.id/bagas/tunnel-please-controller/db/sqlc/repository"
 	"git.fossy.my.id/bagas/tunnel-please-controller/internal/config"
+	"git.fossy.my.id/bagas/tunnel-please-controller/internal/db/sqlc/repository"
 	proto "git.fossy.my.id/bagas/tunnel-please-grpc/gen"
 	"github.com/lestrrat-go/jwx/v3/jwk"
 	"github.com/lestrrat-go/jwx/v3/jwt"
@@ -42,19 +42,19 @@ type Server struct {
 	Database    *repository.Queries
 	Subscribers map[string]*Subscriber
 	mu          *sync.RWMutex
-	authToken   string
 	jwkCache    *jwk.Cache
+	config      config.Config
 	proto.UnimplementedEventServiceServer
 	proto.UnimplementedUserServiceServer
 }
 
-func New(database *repository.Queries, authToken string, jwkCache *jwk.Cache) *Server {
+func New(database *repository.Queries, jwkCache *jwk.Cache, config config.Config) *Server {
 	return &Server{
 		Database:    database,
 		Subscribers: make(map[string]*Subscriber),
 		mu:          new(sync.RWMutex),
-		authToken:   authToken,
 		jwkCache:    jwkCache,
+		config:      config,
 	}
 }
 
@@ -94,7 +94,7 @@ func (s *Server) Subscribe(event grpc.BidiStreamingServer[proto.Node, proto.Even
 		return status.Error(codes.InvalidArgument, "missing identity")
 	}
 	token := payload.AuthEvent.AuthToken
-	if token != s.authToken {
+	if token != s.config.AuthToken() {
 		return status.Error(codes.Unauthenticated, "invalid auth token")
 	}
 
@@ -332,7 +332,7 @@ func (s *Server) StartAPI(ctx context.Context, Addr string) error {
 		WriteTimeout: 15 * time.Second,
 		IdleTimeout:  60 * time.Second,
 	}
-	jwkURL := config.Getenv("JWKS_URL", "")
+	jwkURL := s.config.JwksURL()
 	if jwkURL != "" {
 		registerCtx, cancel := context.WithTimeout(ctx, jwkRegisterTimeout)
 		defer cancel()
@@ -629,6 +629,7 @@ func (s *Server) StartAPI(ctx context.Context, Addr string) error {
 
 	errCh := make(chan error, 1)
 	go func() {
+		log.Printf("Listening api on %s", httpServer.Addr)
 		errCh <- httpServer.ListenAndServe()
 	}()
 
@@ -697,18 +698,19 @@ func (s *Server) StartController(ctx context.Context, Addr string) error {
 
 	serveErr := make(chan error, 1)
 	go func() {
+		log.Printf("Listening controller on %s", s.config.ControllerAddr())
 		serveErr <- grpcServer.Serve(listener)
 	}()
 
 	select {
 	case <-ctx.Done():
 		grpcServer.GracefulStop()
-		err := <-serveErr
+		err = <-serveErr
 		if err != nil {
 			return err
 		}
 		return ctx.Err()
-	case err := <-serveErr:
+	case err = <-serveErr:
 		return err
 	}
 }

main.go

@@ -1,104 +1,25 @@
 package main
 
 import (
-	"context"
-	"crypto/rand"
-	"encoding/base64"
-	"errors"
 	"log"
 	"os"
-	"os/signal"
-	"syscall"
 
-	"git.fossy.my.id/bagas/tunnel-please-controller/db/sqlc/repository"
-	"git.fossy.my.id/bagas/tunnel-please-controller/server"
-	"github.com/jackc/pgx/v5"
-	"github.com/joho/godotenv"
-	"github.com/lestrrat-go/httprc/v3"
-	"github.com/lestrrat-go/jwx/v3/jwk"
+	"git.fossy.my.id/bagas/tunnel-please-controller/internal/bootstrap"
+	"git.fossy.my.id/bagas/tunnel-please-controller/internal/config"
 )
 
 func main() {
-	if _, err := os.Stat(".env"); err == nil {
-		if err = godotenv.Load(".env"); err != nil {
-			log.Printf("Warning: Failed to load .env file: %s", err)
-		}
-	}
-
-	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
-	defer stop()
-
 	log.SetOutput(os.Stdout)
 	log.SetFlags(log.LstdFlags | log.Lshortfile)
 
-	dbURL := os.Getenv("DATABASE_URL")
-	if dbURL == "" {
-		log.Fatal("DATABASE_URL is required")
-	}
-
-	controllerAddr := getenv("CONTROLLER_ADDR", ":8080")
-	apiAddr := getenv("API_ADDR", ":8081")
-	authToken := getenv("AUTH_TOKEN", "")
-	if authToken == "" {
-		authToken = generateAuthToken()
-		log.Printf("No AUTH_TOKEN provided. Generated token: %s", authToken)
-	}
-
-	connect, err := pgx.Connect(ctx, dbURL)
+	conf, err := config.MustLoad()
 	if err != nil {
-		panic(err)
-	}
-	defer func(connect *pgx.Conn, ctx context.Context) {
-		err = connect.Close(ctx)
-		if err != nil {
-			panic(err)
-		}
-	}(connect, ctx)
-
-	repo := repository.New(connect)
-	client := httprc.NewClient()
-	jwkCache, err := jwk.NewCache(ctx, client)
-	if err != nil {
-		log.Printf("failed to initialize jwk cache : %s", err)
-	}
-	s := server.New(repo, authToken, jwkCache)
-
-	log.Printf("Listening controller on %s", controllerAddr)
-	log.Printf("Listening api on %s", apiAddr)
-
-	errCh := make(chan error, 2)
-
-	go func() {
-		if err = s.StartAPI(ctx, apiAddr); err != nil && !errors.Is(err, context.Canceled) {
-			errCh <- err
-		}
-	}()
-
-	go func() {
-		if err = s.StartController(ctx, controllerAddr); err != nil && !errors.Is(err, context.Canceled) {
-			errCh <- err
-		}
-	}()
-
-	select {
-	case <-ctx.Done():
-		log.Printf("shutting down: %v", ctx.Err())
-	case err = <-errCh:
-		log.Fatalf("server error: %v", err)
-	}
+		log.Fatalf("Config load error: %v", err)
 	}
 
-func getenv(key, def string) string {
-	if val := os.Getenv(key); val != "" {
-		return val
-	}
-	return def
-}
+	boot := bootstrap.New(conf)
 
-func generateAuthToken() string {
-	buf := make([]byte, 32)
-	if _, err := rand.Read(buf); err != nil {
-		panic(err)
+	if err = boot.Run(); err != nil {
+		log.Fatalf("Application error: %v", err)
 	}
-	return base64.StdEncoding.EncodeToString(buf)
 }