Source code for airflow.contrib.hooks.wasb_hook

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from airflow.exceptions import AirflowException
from airflow.hooks.base_hook import BaseHook

from azure.storage.blob import BlockBlobService


[docs]class WasbHook(BaseHook): """ Interacts with Azure Blob Storage through the wasb:// protocol. Additional options passed in the 'extra' field of the connection will be passed to the `BlockBlockService()` constructor. For example, authenticate using a SAS token by adding {"sas_token": "YOUR_TOKEN"}. :param wasb_conn_id: Reference to the wasb connection. :type wasb_conn_id: str """ def __init__(self, wasb_conn_id='wasb_default'): self.conn_id = wasb_conn_id self.connection = self.get_conn()
[docs] def get_conn(self): """Return the BlockBlobService object.""" conn = self.get_connection(self.conn_id) service_options = conn.extra_dejson return BlockBlobService(account_name=conn.login, account_key=conn.password, **service_options)
[docs] def check_for_blob(self, container_name, blob_name, **kwargs): """ Check if a blob exists on Azure Blob Storage. :param container_name: Name of the container. :type container_name: str :param blob_name: Name of the blob. :type blob_name: str :param kwargs: Optional keyword arguments that `BlockBlobService.exists()` takes. :type kwargs: object :return: True if the blob exists, False otherwise. :rtype: bool """ return self.connection.exists(container_name, blob_name, **kwargs)
[docs] def check_for_prefix(self, container_name, prefix, **kwargs): """ Check if a prefix exists on Azure Blob storage. :param container_name: Name of the container. :type container_name: str :param prefix: Prefix of the blob. :type prefix: str :param kwargs: Optional keyword arguments that `BlockBlobService.list_blobs()` takes. :type kwargs: object :return: True if blobs matching the prefix exist, False otherwise. :rtype: bool """ matches = self.connection.list_blobs(container_name, prefix, num_results=1, **kwargs) return len(list(matches)) > 0
[docs] def load_file(self, file_path, container_name, blob_name, **kwargs): """ Upload a file to Azure Blob Storage. :param file_path: Path to the file to load. :type file_path: str :param container_name: Name of the container. :type container_name: str :param blob_name: Name of the blob. :type blob_name: str :param kwargs: Optional keyword arguments that `BlockBlobService.create_blob_from_path()` takes. :type kwargs: object """ # Reorder the argument order from airflow.hooks.S3_hook.load_file. self.connection.create_blob_from_path(container_name, blob_name, file_path, **kwargs)
[docs] def load_string(self, string_data, container_name, blob_name, **kwargs): """ Upload a string to Azure Blob Storage. :param string_data: String to load. :type string_data: str :param container_name: Name of the container. :type container_name: str :param blob_name: Name of the blob. :type blob_name: str :param kwargs: Optional keyword arguments that `BlockBlobService.create_blob_from_text()` takes. :type kwargs: object """ # Reorder the argument order from airflow.hooks.S3_hook.load_string. self.connection.create_blob_from_text(container_name, blob_name, string_data, **kwargs)
[docs] def get_file(self, file_path, container_name, blob_name, **kwargs): """ Download a file from Azure Blob Storage. :param file_path: Path to the file to download. :type file_path: str :param container_name: Name of the container. :type container_name: str :param blob_name: Name of the blob. :type blob_name: str :param kwargs: Optional keyword arguments that `BlockBlobService.create_blob_from_path()` takes. :type kwargs: object """ return self.connection.get_blob_to_path(container_name, blob_name, file_path, **kwargs)
[docs] def read_file(self, container_name, blob_name, **kwargs): """ Read a file from Azure Blob Storage and return as a string. :param container_name: Name of the container. :type container_name: str :param blob_name: Name of the blob. :type blob_name: str :param kwargs: Optional keyword arguments that `BlockBlobService.create_blob_from_path()` takes. :type kwargs: object """ return self.connection.get_blob_to_text(container_name, blob_name, **kwargs).content
[docs] def delete_file(self, container_name, blob_name, is_prefix=False, ignore_if_missing=False, **kwargs): """ Delete a file from Azure Blob Storage. :param container_name: Name of the container. :type container_name: str :param blob_name: Name of the blob. :type blob_name: str :param is_prefix: If blob_name is a prefix, delete all matching files :type is_prefix: bool :param ignore_if_missing: if True, then return success even if the blob does not exist. :type ignore_if_missing: bool :param kwargs: Optional keyword arguments that `BlockBlobService.create_blob_from_path()` takes. :type kwargs: object """ if is_prefix: blobs_to_delete = [ blob.name for blob in self.connection.list_blobs( container_name, prefix=blob_name, **kwargs ) ] elif self.check_for_blob(container_name, blob_name): blobs_to_delete = [blob_name] else: blobs_to_delete = [] if not ignore_if_missing and len(blobs_to_delete) == 0: raise AirflowException('Blob(s) not found: {}'.format(blob_name)) for blob_uri in blobs_to_delete: self.log.info("Deleting blob: " + blob_uri) self.connection.delete_blob(container_name, blob_uri, delete_snapshots='include', **kwargs)

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