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from airflow.contrib.hooks.gcs_hook import GoogleCloudStorageHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
from airflow.exceptions import AirflowException
[docs]class GoogleCloudStorageToGoogleCloudStorageOperator(BaseOperator):
"""
Copies objects from a bucket to another, with renaming if requested.
:param source_bucket: The source Google cloud storage bucket where the
object is. (templated)
:type source_bucket: str
: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.
:type source_object: str
:param destination_bucket: The destination Google cloud storage bucket
where the object should be. If the destination_bucket is None, it defaults
to source_bucket. (templated)
:type destination_bucket: str
:param destination_object: The destination name of the object in the
destination Google cloud storage bucket. (templated)
If a wildcard is supplied in the source_object argument, this is the
prefix that will be prepended to the final destination objects' paths.
Note that the source path's part before the wildcard will be removed;
if it needs to be retained it should be appended to destination_object.
For example, with prefix ``foo/*`` and destination_object ``blah/``, the
file ``foo/baz`` will be copied to ``blah/baz``; to retain the prefix write
the destination_object as e.g. ``blah/foo``, in which case the copied file
will be named ``blah/foo/baz``.
:type destination_object: str
: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.
:type move_object: bool
:param google_cloud_storage_conn_id: The connection ID to use when
connecting to Google cloud storage.
:type google_cloud_storage_conn_id: str
:param delegate_to: The account to impersonate, if any.
For this to work, the service account making the request must have
domain-wide delegation enabled.
:type delegate_to: str
:param last_modified_time: When specified, the objects will be copied or moved,
only if they were modified after last_modified_time.
If tzinfo has not been set, UTC will be assumed.
:type last_modified_time: datetime.datetime
:Example:
The following Operator would copy a single file named
``sales/sales-2017/january.avro`` in the ``data`` bucket to the file named
``copied_sales/2017/january-backup.avro`` in the ``data_backup`` bucket ::
copy_single_file = GoogleCloudStorageToGoogleCloudStorageOperator(
task_id='copy_single_file',
source_bucket='data',
source_object='sales/sales-2017/january.avro',
destination_bucket='data_backup',
destination_object='copied_sales/2017/january-backup.avro',
google_cloud_storage_conn_id=google_cloud_conn_id
)
The following Operator would copy all the Avro files from ``sales/sales-2017``
folder (i.e. with names starting with that prefix) in ``data`` bucket to the
``copied_sales/2017`` folder in the ``data_backup`` bucket. ::
copy_files = GoogleCloudStorageToGoogleCloudStorageOperator(
task_id='copy_files',
source_bucket='data',
source_object='sales/sales-2017/*.avro',
destination_bucket='data_backup',
destination_object='copied_sales/2017/',
google_cloud_storage_conn_id=google_cloud_conn_id
)
The following Operator would move all the Avro files from ``sales/sales-2017``
folder (i.e. with names starting with that prefix) in ``data`` bucket to the
same folder in the ``data_backup`` bucket, deleting the original files in the
process. ::
move_files = GoogleCloudStorageToGoogleCloudStorageOperator(
task_id='move_files',
source_bucket='data',
source_object='sales/sales-2017/*.avro',
destination_bucket='data_backup',
move_object=True,
google_cloud_storage_conn_id=google_cloud_conn_id
)
"""
[docs] template_fields = ('source_bucket', 'source_object', 'destination_bucket',
'destination_object',)
@apply_defaults
def __init__(self,
source_bucket,
source_object,
destination_bucket=None,
destination_object=None,
move_object=False,
google_cloud_storage_conn_id='google_cloud_default',
delegate_to=None,
last_modified_time=None,
*args,
**kwargs):
super(GoogleCloudStorageToGoogleCloudStorageOperator,
self).__init__(*args, **kwargs)
self.source_bucket = source_bucket
self.source_object = source_object
self.destination_bucket = destination_bucket
self.destination_object = destination_object
self.move_object = move_object
self.google_cloud_storage_conn_id = google_cloud_storage_conn_id
self.delegate_to = delegate_to
self.last_modified_time = last_modified_time
[docs] def execute(self, context):
hook = GoogleCloudStorageHook(
google_cloud_storage_conn_id=self.google_cloud_storage_conn_id,
delegate_to=self.delegate_to
)
if self.destination_bucket is None:
self.log.warning(
'destination_bucket is None. Defaulting it to source_bucket (%s)',
self.source_bucket)
self.destination_bucket = self.source_bucket
if WILDCARD in self.source_object:
total_wildcards = self.source_object.count(WILDCARD)
if total_wildcards > 1:
error_msg = "Only one wildcard '*' is allowed in source_object parameter. " \
"Found {} in {}.".format(total_wildcards, self.source_object)
raise AirflowException(error_msg)
prefix, delimiter = self.source_object.split(WILDCARD, 1)
objects = hook.list(self.source_bucket, prefix=prefix, delimiter=delimiter)
for source_object in objects:
if self.destination_object is None:
destination_object = source_object
else:
destination_object = source_object.replace(prefix,
self.destination_object, 1)
self._copy_single_object(hook=hook, source_object=source_object,
destination_object=destination_object)
else:
self._copy_single_object(hook=hook, source_object=self.source_object,
destination_object=self.destination_object)
[docs] def _copy_single_object(self, hook, source_object, destination_object):
if self.last_modified_time is not None:
# Check to see if object was modified after last_modified_time
if hook.is_updated_after(self.source_bucket,
source_object,
self.last_modified_time):
self.log.debug("Object has been modified after %s ", self.last_modified_time)
pass
else:
return
self.log.info('Executing copy of gs://%s/%s to gs://%s/%s',
self.source_bucket, source_object,
self.destination_bucket, destination_object)
hook.rewrite(self.source_bucket, source_object,
self.destination_bucket, destination_object)
if self.move_object:
hook.delete(self.source_bucket, source_object)