Added method to run tailscale up without authkey

integration/tailscale.go

@@ -2,6 +2,7 @@ package integration
 
 import (
 	"net/netip"
+	"net/url"
 
 	"tailscale.com/ipn/ipnstate"
 )
@@ -12,6 +13,7 @@ type TailscaleClient interface {
 	Version() string
 	Execute(command []string) (string, error)
 	Up(loginServer, authKey string) error
+	UpWithLoginURL(loginServer string) (*url.URL, error)
 	IPs() ([]netip.Addr, error)
 	FQDN() (string, error)
 	Status() (*ipnstate.Status, error)

integration/tsic/tsic.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"net/netip"
+	"net/url"
 	"strings"
 
 	"github.com/cenkalti/backoff/v4"
@@ -25,6 +26,7 @@ var (
 	errTailscalePingFailed             = errors.New("ping failed")
 	errTailscaleNotLoggedIn            = errors.New("tailscale not logged in")
 	errTailscaleWrongPeerCount         = errors.New("wrong peer count")
+	errTailscaleCannotUpWithoutAuthkey = errors.New("cannot up without authkey")
 )
 
 type TailscaleInContainer struct {
@@ -156,6 +158,37 @@ func (t *TailscaleInContainer) Up(
 	return nil
 }
 
+func (t *TailscaleInContainer) UpWithLoginURL(
+	loginServer string,
+) (*url.URL, error) {
+	command := []string{
+		"tailscale",
+		"up",
+		"-login-server",
+		loginServer,
+		"--hostname",
+		t.hostname,
+	}
+
+	_, stderr, err := t.Execute(command)
+	if err != errTailscaleNotLoggedIn {
+		return nil, errTailscaleCannotUpWithoutAuthkey
+	}
+
+	urlStr := strings.ReplaceAll(stderr, "\nTo authenticate, visit:\n\n\t", "")
+	urlStr = strings.TrimSpace(urlStr)
+
+	// parse URL
+	loginUrl, err := url.Parse(urlStr)
+	if err != nil {
+		log.Printf("Could not parse login URL: %s", err)
+		log.Printf("Original join command result: %s", stderr)
+		return nil, err
+	}
+
+	return loginUrl, nil
+}
+
 func (t *TailscaleInContainer) IPs() ([]netip.Addr, error) {
 	if t.ips != nil && len(t.ips) != 0 {
 		return t.ips, nil