fix issue #5372 on ssh_alt: accept -K option even for a user with NOPASSWD

lib/ansible/runner/connection_plugins/ssh_alt.py

@@ -151,6 +151,9 @@ class Connection(object):
         ssh_cmd = self._password_cmd()
         ssh_cmd += ["ssh", "-C"]
         if not in_data:
+            # we can only use tty when we are not pipelining the modules. piping data into /usr/bin/python
+            # inside a tty automatically invokes the python interactive-mode but the modules are not
+            # compatible with the interactive-mode ("unexpected indent" mainly because of empty lines)
             ssh_cmd += ["-tt"]
         if utils.VERBOSITY > 3:
             ssh_cmd += ["-vvv"]
@@ -200,31 +203,52 @@ class Connection(object):
                 p = subprocess.Popen(ssh_cmd, stdin=subprocess.PIPE,
                                      stdout=subprocess.PIPE, stderr=subprocess.PIPE)
                 stdin = p.stdin
-        
 
         self._send_password()
 
         if self.runner.sudo and sudoable and self.runner.sudo_pass:
+            # several cases are handled for sudo privileges with password
+            # * NOPASSWD (tty & no-tty): detect success_key on stdout
+            # * without NOPASSWD:
+            #   * detect prompt on stdout (tty)
+            #   * detect prompt on stderr (no-tty)
             fcntl.fcntl(p.stdout, fcntl.F_SETFL,
                         fcntl.fcntl(p.stdout, fcntl.F_GETFL) | os.O_NONBLOCK)
+            fcntl.fcntl(p.stderr, fcntl.F_SETFL,
+                        fcntl.fcntl(p.stderr, fcntl.F_GETFL) | os.O_NONBLOCK)
             sudo_output = ''
-            if in_data:
-                # no terminal => no prompt on output. process is waiting for sudo_pass
-                stdin.write(self.runner.sudo_pass + '\n')
+            sudo_errput = ''
+
             while not sudo_output.endswith(prompt) and success_key not in sudo_output:
-                rfd, wfd, efd = select.select([p.stdout], [],
+                rfd, wfd, efd = select.select([p.stdout, p.stderr], [],
                                               [p.stdout], self.runner.timeout)
+                if p.stderr in rfd:
+                    chunk = p.stderr.read()
+                    if not chunk:
+                        raise errors.AnsibleError('ssh connection closed waiting for sudo password prompt')
+                    sudo_errput += chunk
+                    incorrect_password = gettext.dgettext(
+                        "sudo", "Sorry, try again.")
+                    if sudo_errput.strip().endswith("%s%s" % (prompt, incorrect_password)):
+                        raise errors.AnsibleError('Incorrect sudo password')
+                    elif sudo_errput.endswith(prompt):
+                        stdin.write(self.runner.sudo_pass + '\n')
+
                 if p.stdout in rfd:
                     chunk = p.stdout.read()
                     if not chunk:
                         raise errors.AnsibleError('ssh connection closed waiting for sudo password prompt')
                     sudo_output += chunk
-                else:
+
+                if not rfd:
+                    # timeout. wrap up process communication
                     stdout = p.communicate()
                     raise errors.AnsibleError('ssh connection error waiting for sudo password prompt')
+
             if success_key not in sudo_output:
                 stdin.write(self.runner.sudo_pass + '\n')
             fcntl.fcntl(p.stdout, fcntl.F_SETFL, fcntl.fcntl(p.stdout, fcntl.F_GETFL) & ~os.O_NONBLOCK)
+            fcntl.fcntl(p.stderr, fcntl.F_SETFL, fcntl.fcntl(p.stderr, fcntl.F_GETFL) & ~os.O_NONBLOCK)
         # We can't use p.communicate here because the ControlMaster may have stdout open as well
         stdout = ''
         stderr = ''