feat: tailscale integration (#847)

internal/service/auth_service.go

@@ -78,6 +78,7 @@ type AuthService struct {
 	ldap        *LdapService
 	queries     repository.Store
 	oauthBroker *OAuthBrokerService
+	tailscale   *TailscaleService
 
 	loginAttempts        map[string]*LoginAttempt
 	ldapGroupsCache      map[string]*LdapGroupsCache
@@ -99,6 +100,7 @@ func NewAuthService(
 	ldap *LdapService,
 	queries repository.Store,
 	oauthBroker *OAuthBrokerService,
+	tailscale *TailscaleService,
 ) *AuthService {
 	service := &AuthService{
 		log:                  log,
@@ -111,6 +113,7 @@ func NewAuthService(
 		ldap:                 ldap,
 		queries:              queries,
 		oauthBroker:          oauthBroker,
+		tailscale:            tailscale,
 	}
 
 	wg.Go(service.CleanupOAuthSessionsRoutine)
@@ -292,6 +295,10 @@ func (auth *AuthService) IsEmailWhitelisted(email string) bool {
 }
 
 func (auth *AuthService) CreateSession(ctx context.Context, data repository.Session) (*http.Cookie, error) {
+	if data.Provider == "tailscale" && auth.tailscale == nil {
+		return nil, fmt.Errorf("tailscale service not configured, cannot create session for tailscale user")
+	}
+
 	uuid, err := uuid.NewRandom()
 
 	if err != nil {
@@ -328,6 +335,28 @@ func (auth *AuthService) CreateSession(ctx context.Context, data repository.Sess
 		return nil, fmt.Errorf("failed to create session entry: %w", err)
 	}
 
+	if data.Provider == "tailscale" {
+		auth.log.App.Trace().Str("url", fmt.Sprintf("https://%s", auth.tailscale.GetHostname())).Msg("Extracting root domain from Tailscale hostname")
+
+		tsCookieDomain, err := utils.GetCookieDomain(fmt.Sprintf("https://%s", auth.tailscale.GetHostname()))
+
+		if err != nil {
+			return nil, fmt.Errorf("failed to get cookie domain for tailscale user: %w", err)
+		}
+
+		return &http.Cookie{
+			Name:     auth.runtime.SessionCookieName,
+			Value:    session.UUID,
+			Path:     "/",
+			Domain:   fmt.Sprintf(".%s", tsCookieDomain),
+			Expires:  expiresAt,
+			MaxAge:   int(time.Until(expiresAt).Seconds()),
+			Secure:   auth.config.Auth.SecureCookie,
+			HttpOnly: true,
+			SameSite: http.SameSiteLaxMode,
+		}, nil
+	}
+
 	return &http.Cookie{
 		Name:     auth.runtime.SessionCookieName,
 		Value:    session.UUID,

internal/service/tailscale_service.go

@@ -0,0 +1,170 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/tinyauthapp/tinyauth/internal/model"
+	"github.com/tinyauthapp/tinyauth/internal/utils/logger"
+	"tailscale.com/client/local"
+	"tailscale.com/tsnet"
+)
+
+type TailscaleWhoisResponse struct {
+	UserID      string
+	LoginName   string
+	DisplayName string
+	NodeName    string
+	Tags        []string
+}
+
+type TailscaleService struct {
+	log    *logger.Logger
+	wg     *sync.WaitGroup
+	config model.Config
+	ctx    context.Context
+
+	srv *tsnet.Server
+	lc  *local.Client
+	ln  *net.Listener
+	mu  sync.Mutex
+}
+
+func NewTailscaleService(log *logger.Logger, config model.Config, ctx context.Context, wg *sync.WaitGroup) (*TailscaleService, error) {
+	if !config.Tailscale.Enabled {
+		return nil, nil
+	}
+
+	srv := new(tsnet.Server)
+
+	// node options
+	srv.Dir = config.Tailscale.Dir
+	srv.Hostname = config.Tailscale.Hostname
+	srv.AuthKey = config.Tailscale.AuthKey
+	srv.Ephemeral = config.Tailscale.Ephemeral
+
+	// redirect logs to zerolog
+	srv.Logf = log.App.Printf
+	srv.UserLogf = log.App.Printf
+
+	err := srv.Start()
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to start tailscale server: %w", err)
+	}
+
+	lc, err := srv.LocalClient()
+
+	if err != nil {
+		_ = srv.Close()
+		return nil, fmt.Errorf("failed to get tailscale local client: %w", err)
+	}
+
+	service := &TailscaleService{
+		log:    log,
+		wg:     wg,
+		config: config,
+		ctx:    ctx,
+		srv:    srv,
+		lc:     lc,
+	}
+
+	connectCtx, cancel := context.WithTimeout(ctx, 2*time.Minute) // large enough timeout to allow for user to manually authenticate with link if needed
+	defer cancel()
+
+	err = service.waitForConn(connectCtx)
+
+	if err != nil {
+		_ = srv.Close()
+		return nil, fmt.Errorf("failed to connect to tailscale network: %w", err)
+	}
+
+	wg.Go(service.watchAndClose)
+
+	return service, nil
+}
+
+func (ts *TailscaleService) watchAndClose() {
+	<-ts.ctx.Done()
+	ts.log.App.Debug().Msg("Shutting down Tailscale service")
+	ts.mu.Lock()
+	srv := ts.srv
+	ln := ts.ln
+	ts.ln = nil
+	ts.srv = nil
+	ts.mu.Unlock()
+	if ln != nil {
+		(*ts.ln).Close()
+	}
+	if srv != nil {
+		ts.srv.Close()
+	}
+}
+
+func (ts *TailscaleService) Whois(ctx context.Context, addr string) (*TailscaleWhoisResponse, error) {
+	who, err := ts.lc.WhoIs(ctx, addr)
+
+	if err != nil {
+		if errors.Is(err, local.ErrPeerNotFound) {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("failed to get client whois: %w", err)
+	}
+
+	res := TailscaleWhoisResponse{
+		UserID:      who.UserProfile.ID.String(),
+		LoginName:   who.UserProfile.LoginName,
+		DisplayName: who.UserProfile.DisplayName,
+		NodeName:    strings.TrimSuffix(who.Node.Name, "."),
+		Tags:        who.Node.Tags,
+	}
+
+	return &res, nil
+}
+
+func (ts *TailscaleService) CreateListener() (net.Listener, error) {
+	ts.mu.Lock()
+	defer ts.mu.Unlock()
+
+	if ts.ln != nil {
+		return *ts.ln, nil
+	}
+	ln, err := ts.srv.ListenTLS("tcp", ":443")
+	if err != nil {
+		return nil, err
+	}
+	ts.ln = &ln
+	return ln, nil
+}
+
+func (ts *TailscaleService) GetHostname() string {
+	status, err := ts.lc.Status(ts.ctx)
+
+	if err != nil {
+		ts.log.App.Error().Err(err).Msg("Failed to get Tailscale status")
+		return ""
+	}
+
+	return strings.TrimSuffix(status.Self.DNSName, ".")
+}
+
+func (ts *TailscaleService) waitForConn(ctx context.Context) error {
+	for {
+		select {
+		case <-ctx.Done():
+			return fmt.Errorf("timed out waiting for tailscale connection")
+		default:
+			ip4, _ := ts.srv.TailscaleIPs()
+			if !ip4.IsValid() {
+				time.Sleep(1 * time.Second)
+				continue
+			}
+			return nil
+		}
+	}
+}