old_contents: import logging
  from ceph_deploy.lib import remoto
  from ceph_deploy.connection import get_local_connection
  
  
  def can_connect_passwordless(hostname):
      """
      Ensure that current host can SSH remotely to the remote
      host using the ``BatchMode`` option to prevent a password prompt.
  
      That attempt will error with an exit status of 255 and a ``Permission
      denied`` message.
      """
      # Ensure we are not doing this for local hosts
      if not remoto.connection.needs_ssh(hostname):
          return True
  
      logger = logging.getLogger(hostname)
      with get_local_connection(logger) as conn:
          # Check to see if we can login, disabling password prompts
          command = ['ssh', '-CT', '-o', 'BatchMode=yes', hostname]
          out, err, retval = remoto.process.check(conn, command, stop_on_error=False)
          expected_error = 'Permission denied '
          has_key_error = False
          for line in err:
              if expected_error in line:
                  has_key_error = True
  
          if retval == 255 and has_key_error:
              return False
      return True
  
new_contents: import logging
  from ceph_deploy.lib import remoto
  from ceph_deploy.connection import get_local_connection
  
  
  def can_connect_passwordless(hostname):
      """
      Ensure that current host can SSH remotely to the remote
      host using the ``BatchMode`` option to prevent a password prompt.
  
      That attempt will error with an exit status of 255 and a ``Permission
      denied`` message or a``Host key verification failed`` message.
      """
      # Ensure we are not doing this for local hosts
      if not remoto.connection.needs_ssh(hostname):
          return True
  
      logger = logging.getLogger(hostname)
      with get_local_connection(logger) as conn:
          # Check to see if we can login, disabling password prompts
          command = ['ssh', '-CT', '-o', 'BatchMode=yes', hostname]
          out, err, retval = remoto.process.check(conn, command, stop_on_error=False)
          permission_denied_error = 'Permission denied '
          host_key_verify_error = 'Host key verification failed.'
          has_key_error = False
          for line in err:
              if permission_denied_error in line or host_key_verify_error in line:
                  has_key_error = True
  
          if retval == 255 and has_key_error:
              return False
      return True
  
subject: Check if ssh command prints "Host key verification failed." error message