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"""This module contains Google Cloud Storage to SFTP operator."""
from __future__ import annotations
import os
from collections.abc import Sequence
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING
from airflow.exceptions import AirflowException
from airflow.models import BaseOperator
from airflow.providers.google.cloud.hooks.gcs import GCSHook
from airflow.providers.sftp.hooks.sftp import SFTPHook
if TYPE_CHECKING:
from airflow.utils.context import Context
[docs]class GCSToSFTPOperator(BaseOperator):
"""
Transfer files from a Google Cloud Storage bucket to SFTP server.
.. code-block:: python
with models.DAG(
"example_gcs_to_sftp",
start_date=datetime(2020, 6, 19),
schedule=None,
) as dag:
# downloads file to /tmp/sftp/folder/subfolder/file.txt
copy_file_from_gcs_to_sftp = GCSToSFTPOperator(
task_id="file-copy-gsc-to-sftp",
source_bucket="test-gcs-sftp-bucket-name",
source_object="folder/subfolder/file.txt",
destination_path="/tmp/sftp",
)
# moves file to /tmp/data.txt
move_file_from_gcs_to_sftp = GCSToSFTPOperator(
task_id="file-move-gsc-to-sftp",
source_bucket="test-gcs-sftp-bucket-name",
source_object="folder/subfolder/data.txt",
destination_path="/tmp",
move_object=True,
keep_directory_structure=False,
)
.. seealso::
For more information on how to use this operator, take a look at the guide:
:ref:`howto/operator:GCSToSFTPOperator`
:param source_bucket: The source Google Cloud Storage bucket where the
object is. (templated)
:param source_object: The source name of the object to copy in the Google cloud
storage bucket. (templated)
You can use only one wildcard for objects (filenames) within your
bucket. The wildcard can appear inside the object name or at the
end of the object name. Appending a wildcard to the bucket name is
unsupported.
:param destination_path: The sftp remote path. This is the specified directory path for
uploading to the SFTP server.
:param keep_directory_structure: (Optional) When set to False the path of the file
on the bucket is recreated within path passed in destination_path.
:param move_object: When move object is True, the object is moved instead
of copied to the new location. This is the equivalent of a mv command
as opposed to a cp command.
:param gcp_conn_id: (Optional) The connection ID used to connect to Google Cloud.
:param sftp_conn_id: The sftp connection id. The name or identifier for
establishing a connection to the SFTP server.
:param impersonation_chain: Optional service account to impersonate using short-term
credentials, or chained list of accounts required to get the access_token
of the last account in the list, which will be impersonated in the request.
If set as a string, the account must grant the originating account
the Service Account Token Creator IAM role.
If set as a sequence, the identities from the list must grant
Service Account Token Creator IAM role to the directly preceding identity, with first
account from the list granting this role to the originating account (templated).
"""
[docs] template_fields: Sequence[str] = (
"source_bucket",
"source_object",
"destination_path",
"impersonation_chain",
)
def __init__(
self,
*,
source_bucket: str,
source_object: str,
destination_path: str,
keep_directory_structure: bool = True,
move_object: bool = False,
gcp_conn_id: str = "google_cloud_default",
sftp_conn_id: str = "ssh_default",
impersonation_chain: str | Sequence[str] | None = None,
**kwargs,
) -> None:
super().__init__(**kwargs)
self.source_bucket = source_bucket
self.source_object = source_object
self.destination_path = destination_path
self.keep_directory_structure = keep_directory_structure
self.move_object = move_object
self.gcp_conn_id = gcp_conn_id
self.sftp_conn_id = sftp_conn_id
self.impersonation_chain = impersonation_chain
self.sftp_dirs = None
[docs] def execute(self, context: Context):
gcs_hook = GCSHook(
gcp_conn_id=self.gcp_conn_id,
impersonation_chain=self.impersonation_chain,
)
sftp_hook = SFTPHook(self.sftp_conn_id)
if WILDCARD in self.source_object:
total_wildcards = self.source_object.count(WILDCARD)
if total_wildcards > 1:
raise AirflowException(
"Only one wildcard '*' is allowed in source_object parameter. "
f"Found {total_wildcards} in {self.source_object}."
)
prefix, delimiter = self.source_object.split(WILDCARD, 1)
prefix_dirname = os.path.dirname(prefix)
objects = gcs_hook.list(self.source_bucket, prefix=prefix, delimiter=delimiter)
# TODO: After deprecating delimiter and wildcards in source objects,
# remove the previous line and uncomment the following:
# match_glob = f"**/*{delimiter}" if delimiter else None
# objects = gcs_hook.list(self.source_bucket, prefix=prefix, match_glob=match_glob)
for source_object in objects:
destination_path = self._resolve_destination_path(source_object, prefix=prefix_dirname)
self._copy_single_object(gcs_hook, sftp_hook, source_object, destination_path)
self.log.info("Done. Uploaded '%d' files to %s", len(objects), self.destination_path)
else:
destination_path = self._resolve_destination_path(self.source_object)
self._copy_single_object(gcs_hook, sftp_hook, self.source_object, destination_path)
self.log.info("Done. Uploaded '%s' file to %s", self.source_object, destination_path)
def _resolve_destination_path(self, source_object: str, prefix: str | None = None) -> str:
if not self.keep_directory_structure:
if prefix:
source_object = os.path.relpath(source_object, start=prefix)
else:
source_object = os.path.basename(source_object)
return os.path.join(self.destination_path, source_object)
def _copy_single_object(
self,
gcs_hook: GCSHook,
sftp_hook: SFTPHook,
source_object: str,
destination_path: str,
) -> None:
"""Copy single object."""
self.log.info(
"Executing copy of gs://%s/%s to %s",
self.source_bucket,
source_object,
destination_path,
)
dir_path = os.path.dirname(destination_path)
sftp_hook.create_directory(dir_path)
with NamedTemporaryFile("w") as tmp:
gcs_hook.download(
bucket_name=self.source_bucket,
object_name=source_object,
filename=tmp.name,
)
sftp_hook.store_file(destination_path, tmp.name)
if self.move_object:
self.log.info("Executing delete of gs://%s/%s", self.source_bucket, source_object)
gcs_hook.delete(self.source_bucket, source_object)