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import os
from tempfile import NamedTemporaryFile
from airflow.contrib.hooks.azure_data_lake_hook import AzureDataLakeHook
from airflow.contrib.operators.adls_list_operator import AzureDataLakeStorageListOperator
from airflow.contrib.hooks.gcs_hook import GoogleCloudStorageHook, _parse_gcs_url
from airflow.utils.decorators import apply_defaults
[docs]class AdlsToGoogleCloudStorageOperator(AzureDataLakeStorageListOperator):
"""
Synchronizes an Azure Data Lake Storage path with a GCS bucket
:param src_adls: The Azure Data Lake path to find the objects (templated)
:type src_adls: str
:param dest_gcs: The Google Cloud Storage bucket and prefix to
store the objects. (templated)
:type dest_gcs: str
:param replace: If true, replaces same-named files in GCS
:type replace: bool
:param azure_data_lake_conn_id: The connection ID to use when
connecting to Azure Data Lake Storage.
:type azure_data_lake_conn_id: str
: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
**Examples**:
The following Operator would copy a single file named
``hello/world.avro`` from ADLS to the GCS bucket ``mybucket``. Its full
resulting gcs path will be ``gs://mybucket/hello/world.avro`` ::
copy_single_file = AdlsToGoogleCloudStorageOperator(
task_id='copy_single_file',
src_adls='hello/world.avro',
dest_gcs='gs://mybucket',
replace=False,
azure_data_lake_conn_id='azure_data_lake_default',
google_cloud_storage_conn_id='google_cloud_default'
)
The following Operator would copy all parquet files from ADLS
to the GCS bucket ``mybucket``. ::
copy_all_files = AdlsToGoogleCloudStorageOperator(
task_id='copy_all_files',
src_adls='*.parquet',
dest_gcs='gs://mybucket',
replace=False,
azure_data_lake_conn_id='azure_data_lake_default',
google_cloud_storage_conn_id='google_cloud_default'
)
The following Operator would copy all parquet files from ADLS
path ``/hello/world``to the GCS bucket ``mybucket``. ::
copy_world_files = AdlsToGoogleCloudStorageOperator(
task_id='copy_world_files',
src_adls='hello/world/*.parquet',
dest_gcs='gs://mybucket',
replace=False,
azure_data_lake_conn_id='azure_data_lake_default',
google_cloud_storage_conn_id='google_cloud_default'
)
"""
[docs] template_fields = ('src_adls', 'dest_gcs')
@apply_defaults
def __init__(self,
src_adls,
dest_gcs,
azure_data_lake_conn_id,
google_cloud_storage_conn_id,
delegate_to=None,
replace=False,
*args,
**kwargs):
super(AdlsToGoogleCloudStorageOperator, self).__init__(
path=src_adls,
azure_data_lake_conn_id=azure_data_lake_conn_id,
*args,
**kwargs
)
self.src_adls = src_adls
self.dest_gcs = dest_gcs
self.replace = replace
self.google_cloud_storage_conn_id = google_cloud_storage_conn_id
self.delegate_to = delegate_to
[docs] def execute(self, context):
# use the super to list all files in an Azure Data Lake path
files = super(AdlsToGoogleCloudStorageOperator, self).execute(context)
g_hook = GoogleCloudStorageHook(
google_cloud_storage_conn_id=self.google_cloud_storage_conn_id,
delegate_to=self.delegate_to)
if not self.replace:
# if we are not replacing -> list all files in the ADLS path
# and only keep those files which are present in
# ADLS and not in Google Cloud Storage
bucket_name, prefix = _parse_gcs_url(self.dest_gcs)
existing_files = g_hook.list(bucket=bucket_name, prefix=prefix)
files = set(files) - set(existing_files)
if files:
hook = AzureDataLakeHook(
azure_data_lake_conn_id=self.azure_data_lake_conn_id
)
for obj in files:
with NamedTemporaryFile(mode='wb', delete=True) as f:
hook.download_file(local_path=f.name, remote_path=obj)
f.flush()
dest_gcs_bucket, dest_gcs_prefix = _parse_gcs_url(self.dest_gcs)
dest_path = os.path.join(dest_gcs_prefix, obj)
self.log.info("Saving file to %s", dest_path)
g_hook.upload(bucket=dest_gcs_bucket, object=dest_path, filename=f.name)
self.log.info("All done, uploaded %d files to GCS", len(files))
else:
self.log.info("In sync, no files needed to be uploaded to GCS")
return files