initial, rought, not-user-friendly support for multi-domain setup

README.md

@@ -45,7 +45,7 @@ env vars
 * **POSTMOOGLE_HOMESERVER** - homeserver url, eg: `https://matrix.example.com`
 * **POSTMOOGLE_LOGIN** - user login/localpart, eg: `moogle`
 * **POSTMOOGLE_PASSWORD** - user password
-* **POSTMOOGLE_DOMAIN** - SMTP domain to listen for new emails
+* **POSTMOOGLE_DOMAINS** - space separated list of SMTP domains to listen for new emails. The first domain acts as actual domain, all other as aliases
 
 <details>
 <summary>other optional config parameters</summary>

bot/access.go

@@ -73,7 +73,14 @@ func (b *Bot) allowSend(actorID id.UserID, targetRoomID id.RoomID) bool {
 
 // AllowAuth check if SMTP login (email) and password are valid
 func (b *Bot) AllowAuth(email, password string) bool {
-	if !strings.HasSuffix(email, "@"+b.domain) {
+	var suffix bool
+	for _, domain := range b.domains {
+		if strings.HasSuffix(email, "@"+domain) {
+			suffix = true
+			break
+		}
+	}
+	if !suffix {
 		return false
 	}
 

bot/bot.go

@@ -19,7 +19,7 @@ import (
 // Bot represents matrix bot
 type Bot struct {
 	prefix                  string
-	domain                  string
+	domains                 []string
 	allowedUsers            []*regexp.Regexp
 	allowedAdmins           []*regexp.Regexp
 	commands                commandList
@@ -36,16 +36,16 @@ func New(
 	lp *linkpearl.Linkpearl,
 	log *logger.Logger,
 	prefix string,
-	domain string,
+	domains []string,
 	admins []string,
 ) (*Bot, error) {
 	b := &Bot{
-		prefix: prefix,
-		domain: domain,
-		rooms:  sync.Map{},
-		log:    log,
-		lp:     lp,
-		mu:     map[id.RoomID]*sync.Mutex{},
+		prefix:  prefix,
+		domains: domains,
+		rooms:   sync.Map{},
+		log:     log,
+		lp:      lp,
+		mu:      map[id.RoomID]*sync.Mutex{},
 	}
 	users, err := b.initBotUsers()
 	if err != nil {

bot/command.go

@@ -262,7 +262,7 @@ func (b *Bot) sendIntroduction(ctx context.Context, roomID id.RoomID) {
 	msg.WriteString(" SOME_INBOX` command.\n")
 
 	msg.WriteString("You will then be able to send emails to `SOME_INBOX@")
-	msg.WriteString(b.domain)
+	msg.WriteString(b.domains[0])
 	msg.WriteString("` and have them appear in this room.")
 
 	b.SendNotice(ctx, roomID, msg.String())
@@ -301,7 +301,7 @@ func (b *Bot) sendHelp(ctx context.Context) {
 				msg.WriteString(value)
 				if cmd.key == roomOptionMailbox {
 					msg.WriteString("@")
-					msg.WriteString(b.domain)
+					msg.WriteString(b.domains[0])
 				}
 				msg.WriteString("`)")
 			}
@@ -358,8 +358,8 @@ func (b *Bot) runSend(ctx context.Context) {
 		}
 	}
 
-	from := mailbox + "@" + b.domain
-	ID := fmt.Sprintf("<%s@%s>", evt.ID, b.domain)
+	from := mailbox + "@" + b.domains[0]
+	ID := fmt.Sprintf("<%s@%s>", evt.ID, b.domains[0])
 	for _, to := range tos {
 		data := utils.
 			NewEmail(ID, "", subject, from, to, body, "", nil).

bot/command_admin.go

@@ -55,7 +55,7 @@ func (b *Bot) sendMailboxes(ctx context.Context) {
 		msg.WriteString("* `")
 		msg.WriteString(mailbox)
 		msg.WriteString("@")
-		msg.WriteString(b.domain)
+		msg.WriteString(b.domains[0])
 		msg.WriteString("` by ")
 		msg.WriteString(cfg.Owner())
 		msg.WriteString("\n")
@@ -202,5 +202,5 @@ func (b *Bot) runCatchAll(ctx context.Context, commandSlice []string) {
 		return
 	}
 
-	b.SendNotice(ctx, evt.RoomID, fmt.Sprintf("Catch-all is set to: `%s@%s`.", mailbox, b.domain))
+	b.SendNotice(ctx, evt.RoomID, fmt.Sprintf("Catch-all is set to: `%s@%s`.", mailbox, b.domains[0]))
 }

bot/command_owner.go

@@ -58,7 +58,7 @@ func (b *Bot) getOption(ctx context.Context, name string) {
 	}
 
 	if name == roomOptionMailbox {
-		value = value + "@" + b.domain
+		value = value + "@" + b.domains[0]
 	}
 
 	msg := fmt.Sprintf("`%s` of this room is `%s`\n"+
@@ -85,7 +85,7 @@ func (b *Bot) setOption(ctx context.Context, name, value string) {
 	if name == roomOptionMailbox {
 		existingID, ok := b.getMapping(value)
 		if ok && existingID != "" && existingID != evt.RoomID {
-			b.SendNotice(ctx, evt.RoomID, fmt.Sprintf("Mailbox `%s@%s` already taken, kupo", value, b.domain))
+			b.SendNotice(ctx, evt.RoomID, fmt.Sprintf("Mailbox `%s@%s` already taken, kupo", value, b.domains[0]))
 			return
 		}
 	}
@@ -114,7 +114,7 @@ func (b *Bot) setOption(ctx context.Context, name, value string) {
 			b.rooms.Delete(old)
 		}
 		b.rooms.Store(value, evt.RoomID)
-		value = fmt.Sprintf("%s@%s", value, b.domain)
+		value = fmt.Sprintf("%s@%s", value, b.domains[0])
 	}
 
 	err = b.setRoomSettings(evt.RoomID, cfg)

bot/email.go

@@ -112,7 +112,7 @@ func (b *Bot) Send2Matrix(ctx context.Context, email *utils.Email, incoming bool
 	}
 
 	if !incoming {
-		email.MessageID = fmt.Sprintf("<%s@%s>", eventID, b.domain)
+		email.MessageID = fmt.Sprintf("<%s@%s>", eventID, b.domains[0])
 		return b.mta.Send(email.From, email.To, email.Compose(b.getBotSettings().DKIMPrivateKey()))
 	}
 	return nil
@@ -167,7 +167,7 @@ func (b *Bot) Send2Email(ctx context.Context, to, subject, body string) error {
 	if mailbox == "" {
 		return fmt.Errorf("mailbox not configured, kupo")
 	}
-	from := mailbox + "@" + b.domain
+	from := mailbox + "@" + b.domains[0]
 	pTo, pInReplyTo, pSubject := b.getParentEmail(evt)
 	inReplyTo = pInReplyTo
 	if pTo != "" && to == "" {
@@ -189,7 +189,7 @@ func (b *Bot) Send2Email(ctx context.Context, to, subject, body string) error {
 		}
 	}
 
-	ID := evt.ID.String()[1:] + "@" + b.domain
+	ID := evt.ID.String()[1:] + "@" + b.domains[0]
 	data := utils.
 		NewEmail(ID, inReplyTo, subject, from, to, body, "", nil).
 		Compose(b.getBotSettings().DKIMPrivateKey())

cmd/cmd.go

@@ -87,7 +87,7 @@ func initBot(cfg *config.Config) {
 		log.Fatal("cannot initialize matrix bot: %v", err)
 	}
 
-	mxb, err = bot.New(lp, mxlog, cfg.Prefix, cfg.Domain, cfg.Admins)
+	mxb, err = bot.New(lp, mxlog, cfg.Prefix, cfg.Domains, cfg.Admins)
 	if err != nil {
 		// nolint // Fatal = panic, not os.Exit()
 		log.Fatal("cannot start matrix bot: %v", err)
@@ -97,7 +97,7 @@ func initBot(cfg *config.Config) {
 
 func initSMTP(cfg *config.Config) {
 	smtpserv = smtp.NewServer(&smtp.Config{
-		Domain:      cfg.Domain,
+		Domains:     cfg.Domains,
 		Port:        cfg.Port,
 		TLSCert:     cfg.TLS.Cert,
 		TLSKey:      cfg.TLS.Key,

config/config.go

@@ -15,7 +15,7 @@ func New() *Config {
 		Login:        env.String("login", defaultConfig.Login),
 		Password:     env.String("password", defaultConfig.Password),
 		Prefix:       env.String("prefix", defaultConfig.Prefix),
-		Domain:       env.String("domain", defaultConfig.Domain),
+		Domains:      migrateDomains("domain", "domains"),
 		Port:         env.String("port", defaultConfig.Port),
 		NoEncryption: env.Bool("noencryption"),
 		DataSecret:   env.String("data.secret", defaultConfig.DataSecret),
@@ -40,3 +40,13 @@ func New() *Config {
 
 	return cfg
 }
+
+func migrateDomains(oldKey, newKey string) []string {
+	domains := []string{}
+	old := env.String(oldKey, "")
+	if old != "" {
+		domains = append(domains, old)
+	}
+
+	return append(domains, env.Slice(newKey)...)
+}

config/defaults.go

@@ -2,7 +2,7 @@ package config
 
 var defaultConfig = &Config{
 	LogLevel:  "INFO",
-	Domain:    "localhost",
+	Domains:   []string{"localhost"},
 	Port:      "25",
 	Prefix:    "!pm",
 	MaxSize:   1024,

config/types.go

@@ -8,8 +8,8 @@ type Config struct {
 	Login string
 	// Password for login/password auth only
 	Password string
-	// Domain for SMTP
-	Domain string
+	// Domains for SMTP
+	Domains []string
 	// Port for SMTP
 	Port string
 	// RoomID of the admin room

smtp/msa.go

@@ -13,10 +13,10 @@ import (
 
 // msa is mail submission agent, implements smtp.Backend
 type msa struct {
-	log    *logger.Logger
-	domain string
-	bot    Bot
-	mta    utils.MTA
+	log     *logger.Logger
+	domains []string
+	bot     Bot
+	mta     utils.MTA
 }
 
 func (m *msa) newSession(from string, incoming bool) *msasession {
@@ -27,7 +27,7 @@ func (m *msa) newSession(from string, incoming bool) *msasession {
 		incoming: incoming,
 		log:      m.log,
 		bot:      m.bot,
-		domain:   m.domain,
+		domains:  m.domains,
 	}
 }
 

smtp/msasession.go

@@ -19,10 +19,10 @@ import (
 // - receiving emails from remote servers, in which case: `incoming = true`
 // - sending emails from local users, in which case: `incoming = false`
 type msasession struct {
-	log    *logger.Logger
-	bot    Bot
-	mta    utils.MTA
-	domain string
+	log     *logger.Logger
+	bot     Bot
+	mta     utils.MTA
+	domains []string
 
 	ctx      context.Context
 	incoming bool
@@ -46,8 +46,16 @@ func (s *msasession) Rcpt(to string) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("to", to)
 	s.to = to
 
+	//nolint:nestif // TODO
 	if s.incoming {
-		if utils.Hostname(to) != s.domain {
+		var domainok bool
+		for _, domain := range s.domains {
+			if utils.Hostname(to) == domain {
+				domainok = true
+				break
+			}
+		}
+		if !domainok {
 			s.log.Debug("wrong domain of %s", to)
 			return smtp.ErrAuthRequired
 		}

smtp/server.go

@@ -11,8 +11,8 @@ import (
 )
 
 type Config struct {
-	Domain string
-	Port   string
+	Domains []string
+	Port    string
 
 	TLSCert     string
 	TLSKey      string
@@ -39,15 +39,15 @@ func NewServer(cfg *Config) *Server {
 	log := logger.New("smtp/msa.", cfg.LogLevel)
 	sender := NewMTA(cfg.LogLevel)
 	receiver := &msa{
-		log:    log,
-		mta:    sender,
-		bot:    cfg.Bot,
-		domain: cfg.Domain,
+		log:     log,
+		mta:     sender,
+		bot:     cfg.Bot,
+		domains: cfg.Domains,
 	}
 	receiver.bot.SetMTA(sender)
 
 	s := smtp.NewServer(receiver)
-	s.Domain = cfg.Domain
+	s.Domain = cfg.Domains[0]
 	s.ReadTimeout = 10 * time.Second
 	s.WriteTimeout = 10 * time.Second
 	s.MaxMessageBytes = cfg.MaxSize * 1024 * 1024