refactor: unify error handling

app/app.go

@@ -7,7 +7,6 @@ import (
 	"io"
 	"log"
 	"net/http"
-	"os"
 
 	"git.0x0001f346.de/andreas/ablage/config"
 	"github.com/julienschmidt/httprouter"
@@ -25,7 +24,7 @@ var assetScriptJS []byte
 //go:embed assets/style.css
 var assetStyleCSS []byte
 
-func Init() {
+func Init() error {
 	router := httprouter.New()
 
 	router.NotFound = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -57,16 +56,14 @@ func Init() {
 		config.PrintStartupBanner()
 		err := http.ListenAndServe(fmt.Sprintf(":%d", config.GetPortToListenOn()), handler)
 		if err != nil {
-			fmt.Fprintf(os.Stderr, "Ablage exited with error:\n%v\n", err)
+			return fmt.Errorf("Webserver exited with error: %v", err)
-			os.Exit(1)
 		}
-		return
+		return nil
 	}
 
 	tlsCert, err := tls.X509KeyPair(config.GetTLSCertificate(), config.GetTLSKey())
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Faild to parse PEM encoded public/private key pair:\n%v\n", err)
+		return fmt.Errorf("Faild to parse PEM encoded public/private key pair: %v", err)
-		os.Exit(1)
 	}
 
 	server := &http.Server{
@@ -83,9 +80,10 @@ func Init() {
 
 	err = server.ListenAndServeTLS("", "")
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Ablage exited with error:\n%v\n", err)
+		return fmt.Errorf("Webserver exited with error: %v", err)
-		os.Exit(1)
 	}
+
+	return nil
 }
 
 func getClientIP(r *http.Request) string {

config/certs.go

@@ -50,13 +50,13 @@ func generateSelfSignedTLSCertificate() error {
 
 	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &privateKey.PublicKey, privateKey)
 	if err != nil {
-		return err
+		return fmt.Errorf("Failed to create new x509 certificate: %v", err)
 	}
 
 	cert := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
 	key, err := x509.MarshalECPrivateKey(privateKey)
 	if err != nil {
-		return err
+		return fmt.Errorf("Failed to marshal EC private key: %v", err)
 	}
 	keyPEM := pem.EncodeToMemory(&pem.Block{Type: "EC PRIVATE KEY", Bytes: key})
 
@@ -77,17 +77,17 @@ func loadOrGenerateTLSCertificate() error {
 
 	_, err := tls.LoadX509KeyPair(pathTLSCertFile, pathTLSKeyFile)
 	if err != nil {
-		return fmt.Errorf("Error: Failed to load TLS certificate or key: %w", err)
+		return fmt.Errorf("Failed to load TLS certificate or key: %w", err)
 	}
 
 	certData, err := os.ReadFile(pathTLSCertFile)
 	if err != nil {
-		return fmt.Errorf("Error: Failed to read TLS certificate file: %w", err)
+		return fmt.Errorf("Failed to read TLS certificate file: %w", err)
 	}
 
 	keyData, err := os.ReadFile(pathTLSKeyFile)
 	if err != nil {
-		return fmt.Errorf("Error: Failed to read TLS key file: %w", err)
+		return fmt.Errorf("Failed to read TLS key file: %w", err)
 	}
 
 	selfSignedTLSCertificate = certData

config/config.go

@@ -2,7 +2,6 @@ package config
 
 import (
 	"fmt"
-	"os"
 )
 
 const DefaultBasicAuthUsername string = "ablage"
@@ -14,22 +13,22 @@ const VersionString string = "1.1"
 
 var randomBasicAuthPassword string = generateRandomPassword()
 
-func Init() {
+func Init() error {
 	err := gatherDefaultPaths()
 	if err != nil {
-		panic(err)
+		return err
 	}
 
 	parseFlags()
 
 	if GetReadonlyMode() && GetSinkholeMode() {
-		fmt.Println("Error: Cannot enable both readonly and sinkhole modes at the same time.")
+		return fmt.Errorf("Cannot enable both readonly and sinkhole modes at the same time.")
-		os.Exit(1)
 	}
 
 	err = loadOrGenerateTLSCertificate()
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
+		return err
-		os.Exit(1)
 	}
+
+	return nil
 }

config/filesystem.go

@@ -12,7 +12,7 @@ var defaultPathUploadFolder string = ""
 func gatherDefaultPaths() error {
 	execPath, err := os.Executable()
 	if err != nil {
-		return fmt.Errorf("[Error] Could not determine binary path: %v", err)
+		return fmt.Errorf("Could not determine binary path: %v", err)
 	}
 
 	defaultPathDataFolder = filepath.Join(filepath.Dir(execPath), DefaultNameDataFolder)

filesystem/filesystem.go

@@ -10,18 +10,18 @@ import (
 	"git.0x0001f346.de/andreas/ablage/config"
 )
 
-func Init() {
+func Init() error {
 	err := prepareDataFolder()
 	if err != nil {
-		fmt.Println("err")
+		return err
-		os.Exit(1)
 	}
 
 	err = prepareUploadDir()
 	if err != nil {
-		fmt.Println("err")
+		return err
-		os.Exit(1)
 	}
+
+	return nil
 }
 
 func GetHumanReadableSize(bytes int64) string {
@@ -81,23 +81,23 @@ func prepareDataFolder() error {
 	info, err := os.Stat(config.GetPathDataFolder())
 	if os.IsNotExist(err) {
 		if err := os.Mkdir(config.GetPathDataFolder(), 0755); err != nil {
-			return fmt.Errorf("Error: Could not create folder '%s': %v", config.GetPathDataFolder(), err)
+			return fmt.Errorf("Could not create folder '%s': %v", config.GetPathDataFolder(), err)
 		}
 	} else if err != nil {
-		return fmt.Errorf("Error: Could not access '%s': %v", config.GetPathDataFolder(), err)
+		return fmt.Errorf("Could not access '%s': %v", config.GetPathDataFolder(), err)
 	} else if !info.IsDir() {
-		return fmt.Errorf("Error: '%s' exists but is not a directory", config.GetPathDataFolder())
+		return fmt.Errorf("'%s' exists but is not a directory", config.GetPathDataFolder())
 	}
 
 	pathTestFile := filepath.Join(config.GetPathDataFolder(), ".write_test")
 	err = os.WriteFile(pathTestFile, []byte("test"), 0644)
 	if err != nil {
-		return fmt.Errorf("Error: Could not create test file '%s': %v", pathTestFile, err)
+		return fmt.Errorf("Could not create test file '%s': %v", pathTestFile, err)
 	}
 
 	err = os.Remove(pathTestFile)
 	if err != nil {
-		return fmt.Errorf("Error: Could not delete test file '%s': %v", pathTestFile, err)
+		return fmt.Errorf("Could not delete test file '%s': %v", pathTestFile, err)
 	}
 
 	return nil
@@ -112,25 +112,25 @@ func prepareUploadDir() error {
 
 		err = os.RemoveAll(config.GetPathUploadFolder())
 		if err != nil {
-			return fmt.Errorf("Error: Could not delete upload folder '%s': %v", config.GetPathUploadFolder(), err)
+			return fmt.Errorf("Could not delete upload folder '%s': %v", config.GetPathUploadFolder(), err)
 		}
 	} else if !os.IsNotExist(err) {
-		return fmt.Errorf("Error: '%s' exists but is somewhat broken", config.GetPathUploadFolder())
+		return fmt.Errorf("'%s' exists but is somewhat broken", config.GetPathUploadFolder())
 	}
 
 	if err := os.MkdirAll(config.GetPathUploadFolder(), 0755); err != nil {
-		return fmt.Errorf("Error: Could not create upload folder '%s': %v", config.GetPathUploadFolder(), err)
+		return fmt.Errorf("Could not create upload folder '%s': %v", config.GetPathUploadFolder(), err)
 	}
 
 	pathTestFile := filepath.Join(config.GetPathUploadFolder(), ".write_test")
 	err = os.WriteFile(pathTestFile, []byte("test"), 0644)
 	if err != nil {
-		return fmt.Errorf("Error: Could not create test file '%s': %v", pathTestFile, err)
+		return fmt.Errorf("Could not create test file '%s': %v", pathTestFile, err)
 	}
 
 	err = os.Remove(pathTestFile)
 	if err != nil {
-		return fmt.Errorf("Error: Could not delete test file '%s': %v", pathTestFile, err)
+		return fmt.Errorf("Could not delete test file '%s': %v", pathTestFile, err)
 	}
 
 	return nil

main.go

@@ -1,13 +1,30 @@
 package main
 
 import (
+	"fmt"
+	"os"
+
 	"git.0x0001f346.de/andreas/ablage/app"
 	"git.0x0001f346.de/andreas/ablage/config"
 	"git.0x0001f346.de/andreas/ablage/filesystem"
 )
 
 func main() {
-	config.Init()
+	err := config.Init()
-	filesystem.Init()
+	if err != nil {
-	app.Init()
+		fmt.Fprintf(os.Stderr, "[Error] %v\n", err)
+		os.Exit(1)
+	}
+
+	err = filesystem.Init()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "[Error] %v\n", err)
+		os.Exit(1)
+	}
+
+	err = app.Init()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "[Error] %v\n", err)
+		os.Exit(1)
+	}
 }