ipatests: allocate pseudo-terminal only for specific command

While "ktutil" does require a pseudo-terminal on particular systems to
operate, majority of programs do not need it.
At the same time invoking `ssh` with forced pseudo-terminal allocation
interferes with sessions multiplexing feature and increases connection
time. The increase can be as large as 10 seconds in certain cases which
leads to unexpected EOFs of pexpect utility.

Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>

ipatests/pytest_ipa/integration/host.py

@@ -206,9 +206,11 @@ class Host(pytest_multihost.host.Host):
         else:
             return result
 
-    def spawn_expect(self, argv, default_timeout=10, encoding='utf-8'):
-        """Run command on host using IpaTestExpect"""
-        return self.transport.spawn_expect(argv, default_timeout, encoding)
+    def spawn_expect(self, argv, default_timeout=10, encoding='utf-8',
+                     extra_ssh_options=None):
+        """Run command on remote host using IpaTestExpect"""
+        return self.transport.spawn_expect(argv, default_timeout, encoding,
+                                           extra_ssh_options)
 
 class WinHost(pytest_multihost.host.WinHost):
     """

ipatests/pytest_ipa/integration/tasks.py

@@ -2252,7 +2252,8 @@ class KerberosKeyCopier:
 
         mtime_before = get_keytab_mtime()
 
-        with self.host.spawn_expect(paths.KTUTIL, default_timeout=5) as e:
+        with self.host.spawn_expect(paths.KTUTIL, default_timeout=5,
+                                    extra_ssh_options=['-t']) as e:
             e.expect_exact('ktutil:')
             e.sendline('rkt {}'.format(keytab))
             e.expect_exact('ktutil:')

ipatests/pytest_ipa/integration/transport.py

@@ -49,9 +49,11 @@ class IPAOpenSSHTransport(OpenSSHTransport):
 
         return argv
 
-    def spawn_expect(self, argv, default_timeout, encoding):
+    def spawn_expect(self, argv, default_timeout, encoding, extra_ssh_options):
         self.log.debug('Starting pexpect ssh session')
         if isinstance(argv, str):
             argv = [argv]
-        argv = self._get_ssh_argv() + ['-t', '-q'] + argv
+        if extra_ssh_options is None:
+            extra_ssh_options = []
+        argv = self._get_ssh_argv() + ['-q'] + extra_ssh_options + argv
         return IpaTestExpect(argv, default_timeout, encoding)