Add hook, if no jail.local was precreated and fix bug on server start

cmd/server/main.go

@@ -45,8 +45,8 @@ func main() {
 	log.Println("Server listening on port", serverPort, ".")
 
 	// Start the server on port 8080.
-	if err := router.Run(":", serverPort); err != nil {
-		log.Fatalf("Server crashed: %v", err)
+	if err := router.Run(":" + serverPort); err != nil {
+		log.Fatalf("Could not start server: %v\n", err)
 	}
 }
 

internal/config/settings.go

@@ -20,6 +20,7 @@ import (
 	"bufio"
 	"encoding/json"
 	"fmt"
+	"io"
 	"os"
 	"regexp"
 	"strconv"
@@ -58,8 +59,8 @@ type AppSettings struct {
 
 // init paths to key-files
 const (
-	settingsFile    = "fail2ban-ui-settings.json" // this is relative to where the app was started
-	defaultjailFile = "/etc/fail2ban/jail.conf"
+	settingsFile    = "fail2ban-ui-settings.json" // this file is created, relatively to where the app was started
+	defaultJailFile = "/etc/fail2ban/jail.conf"
 	jailFile        = "/etc/fail2ban/jail.local" // Path to jail.local (to override conf-values from jail.conf)
 	jailDFile       = "/etc/fail2ban/jail.d/ui-custom-action.conf"
 	actionFile      = "/etc/fail2ban/action.d/ui-custom-action.conf"
@@ -206,7 +207,19 @@ func initializeFail2banAction() error {
 func setupGeoCustomAction() error {
 	file, err := os.Open(jailFile)
 	if err != nil {
-		return err // File not found or inaccessible
+		// Fallback: Copy default file if jail.local is not found
+		if os.IsNotExist(err) {
+			if err := copyFile(defaultJailFile, jailFile); err != nil {
+				return fmt.Errorf("failed to copy default jail.conf to jail.local: %w", err)
+			}
+			fmt.Println("Successfully created jail.local from jail.conf.")
+			file, err = os.Open(jailFile)
+			if err != nil {
+				return err
+			}
+		} else {
+			return err // Other error
+		}
 	}
 	defer file.Close()
 
@@ -251,6 +264,24 @@ func setupGeoCustomAction() error {
 	return os.WriteFile(jailFile, []byte(output), 0644)
 }
 
+// copyFile copies a file from src to dst. If the destination file does not exist, it will be created.
+func copyFile(src, dst string) error {
+	sourceFile, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer sourceFile.Close()
+
+	destFile, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer destFile.Close()
+
+	_, err = io.Copy(destFile, sourceFile)
+	return err
+}
+
 // ensureJailDConfig checks if the jail.d file exists and creates it if necessary
 func ensureJailDConfig() error {
 	// Check if the file already exists