ssh connection avoid parsiing own debug (#76732)

- Avoids false positives on become strings being echoed back 
   by ssh cli itself
  - added test for debug lines
  - also simplified some of existing test code

changelogs/fragments/ssh_debug_noparse.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ssh connection avoid parsing ssh cli debug lines as they can match expected output at high verbosities.

lib/ansible/plugins/connection/ssh.py

@@ -388,6 +388,7 @@ b_NOT_SSH_ERRORS = (b'Traceback (most recent call last):',  # Python-2.6 when th
                     )
 
 SSHPASS_AVAILABLE = None
+SSH_DEBUG = re.compile(r'^debug\d+: .*')
 
 
 class AnsibleControlPersistBrokenPipeError(AnsibleError):
@@ -837,7 +838,10 @@ class Connection(ConnectionBase):
             suppress_output = False
 
             # display.debug("Examining line (source=%s, state=%s): '%s'" % (source, state, display_line))
-            if self.become.expect_prompt() and self.become.check_password_prompt(b_line):
+            if SSH_DEBUG.match(display_line):
+                # skip lines from ssh debug output to avoid false matches
+                pass
+            elif self.become.expect_prompt() and self.become.check_password_prompt(b_line):
                 display.debug(u"become_prompt: (source=%s, state=%s): '%s'" % (source, state, display_line))
                 self._flags['become_prompt'] = True
                 suppress_output = True

test/units/plugins/connection/test_ssh.py

@@ -102,6 +102,7 @@ class TestConnectionBaseClass(unittest.TestCase):
     def test_plugins_connection_ssh__examine_output(self):
         pc = PlayContext()
         new_stdin = StringIO()
+        become_success_token = b'BECOME-SUCCESS-abcdefghijklmnopqrstuvxyz'
 
         conn = connection_loader.get('ssh', pc, new_stdin)
         conn.set_become_plugin(become_loader.get('sudo'))
@@ -112,24 +113,16 @@ class TestConnectionBaseClass(unittest.TestCase):
         conn.become.check_missing_password = MagicMock()
 
         def _check_password_prompt(line):
-            if b'foo' in line:
-                return True
-            return False
+            return b'foo' in line
 
         def _check_become_success(line):
-            if b'BECOME-SUCCESS-abcdefghijklmnopqrstuvxyz' in line:
-                return True
-            return False
+            return become_success_token in line
 
         def _check_incorrect_password(line):
-            if b'incorrect password' in line:
-                return True
-            return False
+            return b'incorrect password' in line
 
         def _check_missing_password(line):
-            if b'bad password' in line:
-                return True
-            return False
+            return b'bad password' in line
 
         # test examining output for prompt
         conn._flags = dict(
@@ -172,9 +165,9 @@ class TestConnectionBaseClass(unittest.TestCase):
 
         pc.prompt = False
         conn.become.prompt = False
-        pc.success_key = u'BECOME-SUCCESS-abcdefghijklmnopqrstuvxyz'
-        conn.become.success = u'BECOME-SUCCESS-abcdefghijklmnopqrstuvxyz'
-        output, unprocessed = conn._examine_output(u'source', u'state', b'line 1\nline 2\nBECOME-SUCCESS-abcdefghijklmnopqrstuvxyz\nline 3\n', False)
+        pc.success_key = str(become_success_token)
+        conn.become.success = str(become_success_token)
+        output, unprocessed = conn._examine_output(u'source', u'state', b'line 1\nline 2\n%s\nline 3\n' % become_success_token, False)
         self.assertEqual(output, b'line 1\nline 2\nline 3\n')
         self.assertEqual(unprocessed, b'')
         self.assertFalse(conn._flags['become_prompt'])
@@ -182,6 +175,23 @@ class TestConnectionBaseClass(unittest.TestCase):
         self.assertFalse(conn._flags['become_error'])
         self.assertFalse(conn._flags['become_nopasswd_error'])
 
+        # test we dont detect become success from ssh debug: lines
+        conn._flags = dict(
+            become_prompt=False,
+            become_success=False,
+            become_error=False,
+            become_nopasswd_error=False,
+        )
+
+        pc.prompt = False
+        conn.become.prompt = True
+        pc.success_key = str(become_success_token)
+        conn.become.success = str(become_success_token)
+        output, unprocessed = conn._examine_output(u'source', u'state', b'line 1\nline 2\ndebug1: %s\nline 3\n' % become_success_token, False)
+        self.assertEqual(output, b'line 1\nline 2\ndebug1: %s\nline 3\n' % become_success_token)
+        self.assertEqual(unprocessed, b'')
+        self.assertFalse(conn._flags['become_success'])
+
         # test examining output for become failure
         conn._flags = dict(
             become_prompt=False,