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#
# http://www.apache.org/licenses/LICENSE-2.0
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# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
import warnings
from base64 import b64encode
from select import select
from typing import Optional, Sequence, Tuple, Union
from paramiko.client import SSHClient
from airflow.configuration import conf
from airflow.exceptions import AirflowException
from airflow.models import BaseOperator
from airflow.providers.ssh.hooks.ssh import SSHHook
[docs]class SSHOperator(BaseOperator):
"""
SSHOperator to execute commands on given remote host using the ssh_hook.
:param ssh_hook: predefined ssh_hook to use for remote execution.
Either `ssh_hook` or `ssh_conn_id` needs to be provided.
:type ssh_hook: airflow.providers.ssh.hooks.ssh.SSHHook
:param ssh_conn_id: :ref:`ssh connection id<howto/connection:ssh>`
from airflow Connections. `ssh_conn_id` will be ignored if
`ssh_hook` is provided.
:type ssh_conn_id: str
:param remote_host: remote host to connect (templated)
Nullable. If provided, it will replace the `remote_host` which was
defined in `ssh_hook` or predefined in the connection of `ssh_conn_id`.
:type remote_host: str
:param command: command to execute on remote host. (templated)
:type command: str
:param conn_timeout: timeout (in seconds) for maintaining the connection. The default is 10 seconds.
Nullable. If provided, it will replace the `conn_timeout` which was
predefined in the connection of `ssh_conn_id`.
:type conn_timeout: int
:param cmd_timeout: timeout (in seconds) for executing the command. The default is 10 seconds.
:type cmd_timeout: int
:param timeout: (deprecated) timeout (in seconds) for executing the command. The default is 10 seconds.
Use conn_timeout and cmd_timeout parameters instead.
:type timeout: int
:param environment: a dict of shell environment variables. Note that the
server will reject them silently if `AcceptEnv` is not set in SSH config.
:type environment: dict
:param get_pty: request a pseudo-terminal from the server. Set to ``True``
to have the remote process killed upon task timeout.
The default is ``False`` but note that `get_pty` is forced to ``True``
when the `command` starts with ``sudo``.
:type get_pty: bool
"""
[docs] template_fields: Sequence[str] = ('command', 'remote_host')
[docs] template_ext: Sequence[str] = ('.sh',)
[docs] template_fields_renderers = {"command": "bash"}
def __init__(
self,
*,
ssh_hook: Optional[SSHHook] = None,
ssh_conn_id: Optional[str] = None,
remote_host: Optional[str] = None,
command: Optional[str] = None,
timeout: Optional[int] = None,
conn_timeout: Optional[int] = None,
cmd_timeout: Optional[int] = None,
environment: Optional[dict] = None,
get_pty: bool = False,
**kwargs,
) -> None:
super().__init__(**kwargs)
self.ssh_hook = ssh_hook
self.ssh_conn_id = ssh_conn_id
self.remote_host = remote_host
self.command = command
self.timeout = timeout
self.conn_timeout = conn_timeout
self.cmd_timeout = cmd_timeout
if self.conn_timeout is None and self.timeout:
self.conn_timeout = self.timeout
if self.cmd_timeout is None:
self.cmd_timeout = self.timeout if self.timeout else CMD_TIMEOUT
self.environment = environment
self.get_pty = get_pty
if self.timeout:
warnings.warn(
'Parameter `timeout` is deprecated.'
'Please use `conn_timeout` and `cmd_timeout` instead.'
'The old option `timeout` will be removed in a future version.',
DeprecationWarning,
stacklevel=1,
)
[docs] def get_hook(self) -> SSHHook:
if self.ssh_conn_id:
if self.ssh_hook and isinstance(self.ssh_hook, SSHHook):
self.log.info("ssh_conn_id is ignored when ssh_hook is provided.")
else:
self.log.info("ssh_hook is not provided or invalid. Trying ssh_conn_id to create SSHHook.")
self.ssh_hook = SSHHook(ssh_conn_id=self.ssh_conn_id, conn_timeout=self.conn_timeout)
if not self.ssh_hook:
raise AirflowException("Cannot operate without ssh_hook or ssh_conn_id.")
if self.remote_host is not None:
self.log.info(
"remote_host is provided explicitly. "
"It will replace the remote_host which was defined "
"in ssh_hook or predefined in connection of ssh_conn_id."
)
self.ssh_hook.remote_host = self.remote_host
return self.ssh_hook
[docs] def get_ssh_client(self) -> SSHClient:
# Remember to use context manager or call .close() on this when done
self.log.info('Creating ssh_client')
return self.get_hook().get_conn()
[docs] def exec_ssh_client_command(self, ssh_client: SSHClient, command: str) -> Tuple[int, bytes, bytes]:
self.log.info("Running command: %s", command)
# set timeout taken as params
stdin, stdout, stderr = ssh_client.exec_command(
command=command,
get_pty=self.get_pty,
timeout=self.timeout,
environment=self.environment,
)
# get channels
channel = stdout.channel
# closing stdin
stdin.close()
channel.shutdown_write()
agg_stdout = b''
agg_stderr = b''
# capture any initial output in case channel is closed already
stdout_buffer_length = len(stdout.channel.in_buffer)
if stdout_buffer_length > 0:
agg_stdout += stdout.channel.recv(stdout_buffer_length)
# read from both stdout and stderr
while not channel.closed or channel.recv_ready() or channel.recv_stderr_ready():
readq, _, _ = select([channel], [], [], self.cmd_timeout)
for recv in readq:
if recv.recv_ready():
line = stdout.channel.recv(len(recv.in_buffer))
agg_stdout += line
self.log.info(line.decode('utf-8', 'replace').strip('\n'))
if recv.recv_stderr_ready():
line = stderr.channel.recv_stderr(len(recv.in_stderr_buffer))
agg_stderr += line
self.log.warning(line.decode('utf-8', 'replace').strip('\n'))
if (
stdout.channel.exit_status_ready()
and not stderr.channel.recv_stderr_ready()
and not stdout.channel.recv_ready()
):
stdout.channel.shutdown_read()
try:
stdout.channel.close()
except Exception:
# there is a race that when shutdown_read has been called and when
# you try to close the connection, the socket is already closed
# We should ignore such errors (but we should log them with warning)
self.log.warning("Ignoring exception on close", exc_info=True)
break
stdout.close()
stderr.close()
exit_status = stdout.channel.recv_exit_status()
return exit_status, agg_stdout, agg_stderr
[docs] def raise_for_status(self, exit_status: int, stderr: bytes) -> None:
if exit_status != 0:
error_msg = stderr.decode('utf-8')
raise AirflowException(f"error running cmd: {self.command}, error: {error_msg}")
[docs] def run_ssh_client_command(self, ssh_client: SSHClient, command: str) -> bytes:
exit_status, agg_stdout, agg_stderr = self.exec_ssh_client_command(ssh_client, command)
self.raise_for_status(exit_status, agg_stderr)
return agg_stdout
[docs] def execute(self, context=None) -> Union[bytes, str]:
result: Union[bytes, str]
if self.command is None:
raise AirflowException("SSH operator error: SSH command not specified. Aborting.")
# Forcing get_pty to True if the command begins with "sudo".
self.get_pty = self.command.startswith('sudo') or self.get_pty
try:
with self.get_ssh_client() as ssh_client:
result = self.run_ssh_client_command(ssh_client, self.command)
except Exception as e:
raise AirflowException(f"SSH operator error: {str(e)}")
enable_pickling = conf.getboolean('core', 'enable_xcom_pickling')
if not enable_pickling:
result = b64encode(result).decode('utf-8')
return result
[docs] def tunnel(self) -> None:
"""Get ssh tunnel"""
ssh_client = self.ssh_hook.get_conn() # type: ignore[union-attr]
ssh_client.get_transport()