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# to you under the Apache License, Version 2.0 (the
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#
# http://www.apache.org/licenses/LICENSE-2.0
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# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
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# under the License.
"""This module contains Google Cloud Storage to SFTP operator."""
from __future__ import annotations
import os
import posixpath
from collections.abc import Sequence
from functools import cached_property
from pathlib import PurePosixPath
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING
from airflow.providers.common.compat.sdk import AirflowException
from airflow.providers.google.cloud.hooks.gcs import GCSHook
from airflow.providers.google.version_compat import BaseOperator
from airflow.providers.sftp.hooks.sftp import SFTPHook
if TYPE_CHECKING:
from airflow.providers.common.compat.sdk 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 create_intermediate_dirs: (Optional) When set to True the intermediate directories
in the specified file path will be created. It also controls folder markers (objects whose
name ends with ``/``): when True, each marker is created as a directory on the SFTP server;
when False, it is skipped and left in the bucket, even if ``move_object`` is True.
: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",
"gcp_conn_id",
"sftp_conn_id",
)
def __init__(
self,
*,
source_bucket: str,
source_object: str,
destination_path: str,
keep_directory_structure: bool = True,
create_intermediate_dirs: 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)
[docs]
self.source_bucket = source_bucket
[docs]
self.source_object = source_object
[docs]
self.destination_path = destination_path
[docs]
self.keep_directory_structure = keep_directory_structure
[docs]
self.move_object = move_object
[docs]
self.gcp_conn_id = gcp_conn_id
[docs]
self.sftp_conn_id = sftp_conn_id
[docs]
self.impersonation_chain = impersonation_chain
@cached_property
[docs]
def sftp_hook(self):
return SFTPHook(self.sftp_conn_id)
[docs]
def execute(self, context: Context):
gcs_hook = GCSHook(
gcp_conn_id=self.gcp_conn_id,
impersonation_chain=self.impersonation_chain,
)
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, self.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, self.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 = posixpath.relpath(source_object, start=prefix)
else:
source_object = posixpath.basename(source_object)
# GCS object names are arbitrary UTF-8 strings controlled by whoever can
# write to the source bucket, so ``..`` segments or an absolute prefix
# could canonicalise outside ``destination_path`` on the SFTP server.
# The trusted base may contain ".." and refers to the remote server's working directory.
base = posixpath.normpath(self.destination_path)
resolved = posixpath.normpath(posixpath.join(base, source_object))
try:
relative_path = PurePosixPath(resolved).relative_to(base)
except ValueError:
escapes = True
else:
# Pure paths retain ".."; an extra parent beyond a base such as ".." still escapes.
escapes = ".." in relative_path.parts
if escapes:
raise ValueError(
f"Refusing to copy GCS object {source_object!r}: resolved destination "
f"{resolved!r} escapes configured destination_path {self.destination_path!r}."
)
return resolved
def _copy_single_object(
self,
gcs_hook: GCSHook,
sftp_hook: SFTPHook,
source_object: str,
destination_path: str,
) -> None:
"""Copy single object."""
# ``_resolve_destination_path`` strips the trailing slash, so storing a folder marker
# would write a file at the path its children need as a directory.
if source_object.endswith("/"):
if not self.create_intermediate_dirs:
self.log.info(
"Skipping folder marker gs://%s/%s because create_intermediate_dirs is False",
self.source_bucket,
source_object,
)
return
self.log.info(
"Creating directory %s for folder marker gs://%s/%s",
destination_path,
self.source_bucket,
source_object,
)
sftp_hook.create_directory(destination_path)
else:
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)
if self.create_intermediate_dirs:
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)
[docs]
def get_openlineage_facets_on_start(self):
from airflow.providers.common.compat.openlineage.facet import Dataset
from airflow.providers.google.cloud.openlineage.utils import extract_ds_name_from_gcs_path
from airflow.providers.openlineage.extractors import OperatorLineage
source_name = extract_ds_name_from_gcs_path(f"{self.source_object}")
dest_name = f"{self.destination_path}"
if self.keep_directory_structure:
dest_name = os.path.join(dest_name, source_name if source_name != "/" else "")
elif WILDCARD not in self.source_object:
dest_name = os.path.join(dest_name, os.path.basename(self.source_object))
dest_name = dest_name.rstrip("/") if dest_name != "/" else "/"
return OperatorLineage(
inputs=[
Dataset(
namespace=f"gs://{self.source_bucket}",
name=source_name,
)
],
outputs=[
Dataset(
namespace=f"file://{self.sftp_hook.remote_host}:{self.sftp_hook.port}",
name=dest_name,
)
],
)