# -*- coding: utf-8 -*-
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from airflow.contrib.hooks.datastore_hook import DatastoreHook
from airflow.contrib.hooks.gcs_hook import GoogleCloudStorageHook
from airflow.exceptions import AirflowException
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
[docs]class DatastoreExportOperator(BaseOperator):
"""
Export entities from Google Cloud Datastore to Cloud Storage
:param bucket: name of the cloud storage bucket to backup data
:type bucket: str
:param namespace: optional namespace path in the specified Cloud Storage bucket
to backup data. If this namespace does not exist in GCS, it will be created.
:type namespace: str
:param datastore_conn_id: the name of the Datastore connection id to use
:type datastore_conn_id: str
:param cloud_storage_conn_id: the name of the cloud storage connection id to
force-write backup
:type 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 entity_filter: description of what data from the project is included in the
export, refer to
https://cloud.google.com/datastore/docs/reference/rest/Shared.Types/EntityFilter
:type entity_filter: dict
:param labels: client-assigned labels for cloud storage
:type labels: dict
:param polling_interval_in_seconds: number of seconds to wait before polling for
execution status again
:type polling_interval_in_seconds: int
:param overwrite_existing: if the storage bucket + namespace is not empty, it will be
emptied prior to exports. This enables overwriting existing backups.
:type overwrite_existing: bool
:param xcom_push: push operation name to xcom for reference
:type xcom_push: bool
"""
@apply_defaults
def __init__(self,
bucket,
namespace=None,
datastore_conn_id='google_cloud_default',
cloud_storage_conn_id='google_cloud_default',
delegate_to=None,
entity_filter=None,
labels=None,
polling_interval_in_seconds=10,
overwrite_existing=False,
xcom_push=False,
*args,
**kwargs):
super(DatastoreExportOperator, self).__init__(*args, **kwargs)
self.datastore_conn_id = datastore_conn_id
self.cloud_storage_conn_id = cloud_storage_conn_id
self.delegate_to = delegate_to
self.bucket = bucket
self.namespace = namespace
self.entity_filter = entity_filter
self.labels = labels
self.polling_interval_in_seconds = polling_interval_in_seconds
self.overwrite_existing = overwrite_existing
self.xcom_push = xcom_push
[docs] def execute(self, context):
self.log.info('Exporting data to Cloud Storage bucket ' + self.bucket)
if self.overwrite_existing and self.namespace:
gcs_hook = GoogleCloudStorageHook(self.cloud_storage_conn_id)
objects = gcs_hook.list(self.bucket, prefix=self.namespace)
for o in objects:
gcs_hook.delete(self.bucket, o)
ds_hook = DatastoreHook(self.datastore_conn_id, self.delegate_to)
result = ds_hook.export_to_storage_bucket(bucket=self.bucket,
namespace=self.namespace,
entity_filter=self.entity_filter,
labels=self.labels)
operation_name = result['name']
result = ds_hook.poll_operation_until_done(operation_name,
self.polling_interval_in_seconds)
state = result['metadata']['common']['state']
if state != 'SUCCESSFUL':
raise AirflowException('Operation failed: result={}'.format(result))
if self.xcom_push:
return result