nixos/tests/test-driver: add shell_interact

nixos/lib/test-driver/test-driver.py

@@ -21,6 +21,7 @@ import shutil
 import socket
 import subprocess
 import sys
+import telnetlib
 import tempfile
 import time
 import traceback
@@ -455,6 +456,15 @@ class Machine:
                 return (status_code, output)
             output += chunk
 
+    def shell_interact(self) -> None:
+        """Allows you to interact with the guest shell
+
+        Should only be used during testing, not in the production test."""
+        self.connect()
+        telnet = telnetlib.Telnet()
+        telnet.sock = self.shell  # type: ignore
+        telnet.interact()
+
     def succeed(self, *commands: str) -> str:
         """Execute each command and check that it succeeds."""
         output = ""