support STARTTLS

main.go

@@ -4,57 +4,85 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"log"
+	"net/smtp"
 	"os"
 	"os/signal"
+	"syscall"
+
+	log "github.com/flashmob/go-guerrilla/log"
 )
 
-type loggerLevels struct {
-	Debug *log.Logger
-	Error *log.Logger
-}
+var Logger log.Logger
 
 type mailRelayConfig struct {
-	SMTPServer      string		`json:"smtp_server"`
-	SMTPPort        int			`json:"smtp_port"`
-	SMTPUsername    string		`json:"smtp_username"`
-	SMTPPassword    string		`json:"smtp_password"`
-	LocalListenIP   string		`json:"local_listen_ip"`
-	LocalListenPort int    		`json:"local_listen_port"`
-	AllowedHosts	[]string	`json:"allowed_hosts"`
+	SMTPServer      string   `json:"smtp_server"`
+	SMTPPort        int      `json:"smtp_port"`
+	SMTPStartTLS    bool     `json:"smtp_starttls"`
+	SMTPUsername    string   `json:"smtp_username"`
+	SMTPPassword    string   `json:"smtp_password"`
+	LocalListenIP   string   `json:"local_listen_ip"`
+	LocalListenPort int      `json:"local_listen_port"`
+	AllowedHosts    []string `json:"allowed_hosts"`
 }
 
-// Logger provides application logging.
-var Logger loggerLevels
-
 func main() {
+	err := run()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
+		os.Exit(1)
+	}
+	os.Exit(0)
+}
 
-	Logger.Debug = log.New(os.Stdout, "debug: ", log.Ldate|log.Ltime|log.Lshortfile)
-	Logger.Error = log.New(os.Stderr, "error: ", log.Ldate|log.Ltime|log.Lshortfile)
-
+func run() error {
 	var configFile string
+	var test bool
+	var testsender string
+	var testrcpt string
+	var verbose bool
 	flag.StringVar(&configFile, "config", "/etc/mailrelay.json", "specifies JSON config file")
+	flag.BoolVar(&test, "test", false, "sends a test message to SMTP server")
+	flag.StringVar(&testsender, "sender", "", "used with 'test' to specify sender email address")
+	flag.StringVar(&testrcpt, "rcpt", "", "used with 'test' to specify recipient email address")
+	flag.BoolVar(&verbose, "verbose", false, "verbose output")
 	flag.Parse()
 
 	appConfig, err := loadConfig(configFile)
 	if err != nil {
-		Logger.Error.Fatalf("loading config: %v", err)
+		flag.Usage()
+		return fmt.Errorf("loading config: %w", err)
 	}
 
-	err = Start(appConfig)
+	err = Start(appConfig, verbose)
 	if err != nil {
-		Logger.Error.Fatalf("starting server: %v", err)
+		flag.Usage()
+		return fmt.Errorf("starting server: %w", err)
+	}
+
+	logLevel := "info"
+	if verbose {
+		logLevel = "debug"
+	}
+	Logger, err = log.GetLogger("stdout", logLevel)
+	if err != nil {
+		return fmt.Errorf("creating logger: %w", err)
+	}
+
+	if test {
+		err = sendTest(testsender, testrcpt, appConfig.LocalListenPort)
+		if err != nil {
+			return fmt.Errorf("sending test message: %w", err)
+		}
+		return nil
 	}
 
 	// Wait for SIGINT
 	c := make(chan os.Signal, 1)
-	signal.Notify(c, os.Interrupt)
-	signal.Notify(c, os.Kill)
+	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
 
 	// Block until a signal is received.
-	s := <-c
-	fmt.Println("Got signal:", s)
-	os.Exit(0)
+	<-c
+	return nil
 }
 
 func loadConfig(path string) (*mailRelayConfig, error) {
@@ -71,3 +99,33 @@ func loadConfig(path string) (*mailRelayConfig, error) {
 	}
 	return &cfg, nil
 }
+
+// sendTest sends a test message to the SMTP server specified in mailrelay.json
+func sendTest(sender string, rcpt string, port int) error {
+	conn, err := smtp.Dial(fmt.Sprintf("localhost:%d", port))
+	if err != nil {
+		return err
+	}
+
+	if err := conn.Mail(sender); err != nil {
+		return err
+	}
+	if err := conn.Rcpt(rcpt); err != nil {
+		return err
+	}
+
+	writeBody := func(c *smtp.Client) error {
+		wc, err := conn.Data()
+		if err != nil {
+			return err
+		}
+		defer wc.Close()
+		_, err = fmt.Fprintf(wc, "From: %s\nSubject: Test message\n\nThis is a test email from mailrelay.\n", sender)
+		return err
+	}
+	if err := writeBody(conn); err != nil {
+		return err
+	}
+
+	return conn.Quit()
+}