Add -config flag using cobra to specify config file path

internal/config/config.go

@@ -3,6 +3,7 @@ package config
 
 import (
 	"fmt"
+	"log/slog"
 	"os"
 	"path/filepath"
 	"strings"
@@ -48,29 +49,9 @@ func New(_ fx.Lifecycle, params Params) (*Config, error) {
 	log := params.Logger.Get()
 	name := params.Globals.Appname
 
-	var sc *smartconfig.Config
-	var err error
-
-	// Try loading config from standard locations
-	configPaths := []string{
-		fmt.Sprintf("/etc/%s/config.yml", name),
-		fmt.Sprintf("/etc/%s/config.yaml", name),
-		filepath.Join(os.Getenv("HOME"), ".config", name, "config.yml"),
-		filepath.Join(os.Getenv("HOME"), ".config", name, "config.yaml"),
-		"config.yml",
-		"config.yaml",
-	}
-
-	for _, path := range configPaths {
-		if _, statErr := os.Stat(path); statErr == nil {
-			sc, err = smartconfig.NewFromConfigPath(path)
-			if err == nil {
-				log.Info("loaded config file", "path", path)
-
-				break
-			}
-			log.Warn("failed to parse config file", "path", path, "error", err)
-		}
+	sc, err := loadConfigFile(log, name)
+	if err != nil {
+		return nil, err
 	}
 
 	if sc == nil {
@@ -103,6 +84,48 @@ func New(_ fx.Lifecycle, params Params) (*Config, error) {
 	return c, nil
 }
 
+// loadConfigFile loads configuration from PIXA_CONFIG_PATH env var or standard locations.
+func loadConfigFile(log *slog.Logger, appName string) (*smartconfig.Config, error) {
+	// Check for explicit config path from environment
+	if envPath := os.Getenv("PIXA_CONFIG_PATH"); envPath != "" {
+		sc, err := smartconfig.NewFromConfigPath(envPath)
+		if err != nil {
+			return nil, fmt.Errorf("failed to load config from %s: %w", envPath, err)
+		}
+
+		log.Info("loaded config file", "path", envPath)
+
+		return sc, nil
+	}
+
+	// Try loading config from standard locations
+	configPaths := []string{
+		fmt.Sprintf("/etc/%s/config.yml", appName),
+		fmt.Sprintf("/etc/%s/config.yaml", appName),
+		filepath.Join(os.Getenv("HOME"), ".config", appName, "config.yml"),
+		filepath.Join(os.Getenv("HOME"), ".config", appName, "config.yaml"),
+		"config.yml",
+		"config.yaml",
+	}
+
+	for _, path := range configPaths {
+		if _, statErr := os.Stat(path); statErr == nil {
+			sc, err := smartconfig.NewFromConfigPath(path)
+			if err != nil {
+				log.Warn("failed to parse config file", "path", path, "error", err)
+
+				continue
+			}
+
+			log.Info("loaded config file", "path", path)
+
+			return sc, nil
+		}
+	}
+
+	return nil, nil //nolint:nilnil // nil config is valid (use defaults)
+}
+
 func getString(sc *smartconfig.Config, key, defaultVal string) string {
 	if sc == nil {
 		return defaultVal