release: 1.1.0 - YAML config, web server, web auth and UI improvements

config.go

@@ -0,0 +1,195 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	SMTP SMTPConfig `yaml:"smtp"`
+	Web  WebConfig  `yaml:"web"`
+}
+
+type SMTPConfig struct {
+	ListenAddress  string `yaml:"listen_address"`
+	ListenPort     int    `yaml:"listen_port"`
+	StorageDir     string `yaml:"storage_dir"`
+	DomainName     string `yaml:"domain_name"`
+	MaxMessageSize int64  `yaml:"max_message_size"`
+	EnableAuth     bool   `yaml:"enable_auth"`
+}
+
+type WebConfig struct {
+	Enabled   bool            `yaml:"enabled"`
+	Port      int             `yaml:"port"`
+	Directory string          `yaml:"directory"`
+	BasicAuth BasicAuthConfig `yaml:"basic_auth"`
+}
+
+type BasicAuthConfig struct {
+	Enabled  bool   `yaml:"enabled"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+}
+
+func getExecutableDir() (string, error) {
+	exe, err := os.Executable()
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Dir(exe), nil
+}
+
+func defaultConfig() *Config {
+	return &Config{
+		SMTP: SMTPConfig{
+			ListenAddress:  "0.0.0.0",
+			ListenPort:     1025,
+			StorageDir:     "emails",
+			DomainName:     "m.ric930.ru",
+			MaxMessageSize: 50 * 1024 * 1024,
+			EnableAuth:     true,
+		},
+		Web: WebConfig{
+			Enabled:   true,
+			Port:      8089,
+			Directory: "web",
+			BasicAuth: BasicAuthConfig{
+				Enabled:  true,
+				Username: "admin",
+				Password: "admin",
+			},
+		},
+	}
+}
+
+func resolveConfigPaths(cfg *Config, exeDir string) {
+	if !filepath.IsAbs(cfg.SMTP.StorageDir) {
+		cfg.SMTP.StorageDir = filepath.Join(exeDir, cfg.SMTP.StorageDir)
+	}
+
+	if !filepath.IsAbs(cfg.Web.Directory) {
+		cfg.Web.Directory = filepath.Join(exeDir, cfg.Web.Directory)
+	}
+}
+
+func validateConfig(cfg *Config) error {
+	if cfg.SMTP.ListenPort < 1 || cfg.SMTP.ListenPort > 65535 {
+		return fmt.Errorf("invalid smtp.listen_port: %d", cfg.SMTP.ListenPort)
+	}
+
+	if cfg.SMTP.StorageDir == "" {
+		return fmt.Errorf("smtp.storage_dir must not be empty")
+	}
+
+	if cfg.SMTP.DomainName == "" {
+		return fmt.Errorf("smtp.domain_name must not be empty")
+	}
+
+	if cfg.SMTP.MaxMessageSize <= 0 {
+		return fmt.Errorf("smtp.max_message_size must be greater than zero")
+	}
+
+	if cfg.Web.Enabled {
+		if cfg.Web.Port < 1 || cfg.Web.Port > 65535 {
+			return fmt.Errorf("invalid web.port: %d", cfg.Web.Port)
+		}
+
+		if cfg.Web.Directory == "" {
+			return fmt.Errorf("web.directory must not be empty")
+		}
+
+		if cfg.Web.BasicAuth.Enabled {
+			if cfg.Web.BasicAuth.Username == "" {
+				return fmt.Errorf("web.basic_auth.username must not be empty")
+			}
+
+			if cfg.Web.BasicAuth.Password == "" {
+				return fmt.Errorf("web.basic_auth.password must not be empty")
+			}
+		}
+	}
+
+	return nil
+}
+
+func LoadConfig(configPath string) (*Config, error) {
+	exeDir, err := getExecutableDir()
+	if err != nil {
+		log.Printf(
+			"Warning: cannot get executable directory: %v, using current directory",
+			err,
+		)
+		exeDir = "."
+	}
+
+	finalConfigPath := configPath
+	if !filepath.IsAbs(finalConfigPath) {
+		finalConfigPath = filepath.Join(exeDir, finalConfigPath)
+	}
+
+	data, err := os.ReadFile(finalConfigPath)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return nil, fmt.Errorf("failed to read config: %w", err)
+		}
+
+		cfg := defaultConfig()
+
+		cfgData, marshalErr := yaml.Marshal(cfg)
+		if marshalErr != nil {
+			return nil, fmt.Errorf(
+				"failed to create default config data: %w",
+				marshalErr,
+			)
+		}
+
+		if writeErr := os.WriteFile(finalConfigPath, cfgData, 0600); writeErr != nil {
+			return nil, fmt.Errorf(
+				"failed to create default config: %w",
+				writeErr,
+			)
+		}
+
+		log.Printf("Created default config at %s", finalConfigPath)
+		log.Printf(
+			"WARNING: change the default web Basic Auth password in %s",
+			finalConfigPath,
+		)
+
+		resolveConfigPaths(cfg, exeDir)
+
+		if err := validateConfig(cfg); err != nil {
+			return nil, err
+		}
+
+		return cfg, nil
+	}
+
+	var cfg Config
+
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return nil, fmt.Errorf(
+			"failed to parse YAML config %s: %w",
+			finalConfigPath,
+			err,
+		)
+	}
+
+	if err := validateConfig(&cfg); err != nil {
+		return nil, fmt.Errorf(
+			"invalid config %s: %w",
+			finalConfigPath,
+			err,
+		)
+	}
+
+	resolveConfigPaths(&cfg, exeDir)
+
+	return &cfg, nil
+}