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"""This module contains a Google Cloud Spanner Hook."""
from typing import Callable, List, Optional, Sequence, Union
from google.api_core.exceptions import AlreadyExists, GoogleAPICallError
from google.cloud.spanner_v1.client import Client
from google.cloud.spanner_v1.database import Database
from google.cloud.spanner_v1.instance import Instance
from google.cloud.spanner_v1.transaction import Transaction
from google.longrunning.operations_grpc_pb2 import Operation
from airflow.exceptions import AirflowException
from airflow.providers.google.common.consts import CLIENT_INFO
from airflow.providers.google.common.hooks.base_google import GoogleBaseHook
[docs]class SpannerHook(GoogleBaseHook):
"""
Hook for Google Cloud Spanner APIs.
All the methods in the hook where project_id is used must be called with
keyword arguments rather than positional.
"""
def __init__(
self,
gcp_conn_id: str = "google_cloud_default",
delegate_to: Optional[str] = None,
impersonation_chain: Optional[Union[str, Sequence[str]]] = None,
) -> None:
super().__init__(
gcp_conn_id=gcp_conn_id,
delegate_to=delegate_to,
impersonation_chain=impersonation_chain,
)
self._client = None
def _get_client(self, project_id: str) -> Client:
"""
Provides a client for interacting with the Cloud Spanner API.
:param project_id: The ID of the Google Cloud project.
:return: Client
:rtype: google.cloud.spanner_v1.client.Client
"""
if not self._client:
self._client = Client(
project=project_id, credentials=self._get_credentials(), client_info=CLIENT_INFO
)
return self._client
@GoogleBaseHook.fallback_to_default_project_id
[docs] def get_instance(
self,
instance_id: str,
project_id: str,
) -> Instance:
"""
Gets information about a particular instance.
:param project_id: Optional, The ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:param instance_id: The ID of the Cloud Spanner instance.
:return: Spanner instance
:rtype: google.cloud.spanner_v1.instance.Instance
"""
instance = self._get_client(project_id=project_id).instance(instance_id=instance_id)
if not instance.exists():
return None
return instance
def _apply_to_instance(
self,
project_id: str,
instance_id: str,
configuration_name: str,
node_count: int,
display_name: str,
func: Callable[[Instance], Operation],
) -> None:
"""
Invokes a method on a given instance by applying a specified Callable.
:param project_id: The ID of the Google Cloud project that owns the Cloud Spanner database.
:param instance_id: The ID of the instance.
:param configuration_name: Name of the instance configuration defining how the
instance will be created. Required for instances which do not yet exist.
:param node_count: (Optional) Number of nodes allocated to the instance.
:param display_name: (Optional) The display name for the instance in the Cloud
Console UI. (Must be between 4 and 30 characters.) If this value is not set
in the constructor, will fall back to the instance ID.
:param func: Method of the instance to be called.
"""
instance = self._get_client(project_id=project_id).instance(
instance_id=instance_id,
configuration_name=configuration_name,
node_count=node_count,
display_name=display_name,
)
try:
operation = func(instance) # type: Operation
except GoogleAPICallError as e:
self.log.error('An error occurred: %s. Exiting.', e.message)
raise e
if operation:
result = operation.result()
self.log.info(result)
@GoogleBaseHook.fallback_to_default_project_id
[docs] def create_instance(
self,
instance_id: str,
configuration_name: str,
node_count: int,
display_name: str,
project_id: str,
) -> None:
"""
Creates a new Cloud Spanner instance.
:param instance_id: The ID of the Cloud Spanner instance.
:param configuration_name: The name of the instance configuration defining how the
instance will be created. Possible configuration values can be retrieved via
https://cloud.google.com/spanner/docs/reference/rest/v1/projects.instanceConfigs/list
:param node_count: (Optional) The number of nodes allocated to the Cloud Spanner
instance.
:param display_name: (Optional) The display name for the instance in the Google Cloud Console.
Must be between 4 and 30 characters. If this value is not passed, the name falls back
to the instance ID.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:return: None
"""
self._apply_to_instance(
project_id, instance_id, configuration_name, node_count, display_name, lambda x: x.create()
)
@GoogleBaseHook.fallback_to_default_project_id
[docs] def update_instance(
self,
instance_id: str,
configuration_name: str,
node_count: int,
display_name: str,
project_id: str,
) -> None:
"""
Updates an existing Cloud Spanner instance.
:param instance_id: The ID of the Cloud Spanner instance.
:param configuration_name: The name of the instance configuration defining how the
instance will be created. Possible configuration values can be retrieved via
https://cloud.google.com/spanner/docs/reference/rest/v1/projects.instanceConfigs/list
:param node_count: (Optional) The number of nodes allocated to the Cloud Spanner
instance.
:param display_name: (Optional) The display name for the instance in the Google Cloud
Console. Must be between 4 and 30 characters. If this value is not set in
the constructor, the name falls back to the instance ID.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:return: None
"""
self._apply_to_instance(
project_id, instance_id, configuration_name, node_count, display_name, lambda x: x.update()
)
@GoogleBaseHook.fallback_to_default_project_id
[docs] def delete_instance(self, instance_id: str, project_id: str) -> None:
"""
Deletes an existing Cloud Spanner instance.
:param instance_id: The ID of the Cloud Spanner instance.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:return: None
"""
instance = self._get_client(project_id=project_id).instance(instance_id)
try:
instance.delete()
return
except GoogleAPICallError as e:
self.log.error('An error occurred: %s. Exiting.', e.message)
raise e
@GoogleBaseHook.fallback_to_default_project_id
[docs] def get_database(
self,
instance_id: str,
database_id: str,
project_id: str,
) -> Optional[Database]:
"""
Retrieves a database in Cloud Spanner. If the database does not exist
in the specified instance, it returns None.
:param instance_id: The ID of the Cloud Spanner instance.
:param database_id: The ID of the database in Cloud Spanner.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:return: Database object or None if database does not exist
:rtype: google.cloud.spanner_v1.database.Database or None
"""
instance = self._get_client(project_id=project_id).instance(instance_id=instance_id)
if not instance.exists():
raise AirflowException(f"The instance {instance_id} does not exist in project {project_id} !")
database = instance.database(database_id=database_id)
if not database.exists():
return None
return database
@GoogleBaseHook.fallback_to_default_project_id
[docs] def create_database(
self,
instance_id: str,
database_id: str,
ddl_statements: List[str],
project_id: str,
) -> None:
"""
Creates a new database in Cloud Spanner.
:param instance_id: The ID of the Cloud Spanner instance.
:param database_id: The ID of the database to create in Cloud Spanner.
:param ddl_statements: The string list containing DDL for the new database.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:return: None
"""
instance = self._get_client(project_id=project_id).instance(instance_id=instance_id)
if not instance.exists():
raise AirflowException(f"The instance {instance_id} does not exist in project {project_id} !")
database = instance.database(database_id=database_id, ddl_statements=ddl_statements)
try:
operation = database.create() # type: Operation
except GoogleAPICallError as e:
self.log.error('An error occurred: %s. Exiting.', e.message)
raise e
if operation:
result = operation.result()
self.log.info(result)
@GoogleBaseHook.fallback_to_default_project_id
[docs] def update_database(
self,
instance_id: str,
database_id: str,
ddl_statements: List[str],
project_id: str,
operation_id: Optional[str] = None,
) -> None:
"""
Updates DDL of a database in Cloud Spanner.
:param instance_id: The ID of the Cloud Spanner instance.
:param database_id: The ID of the database in Cloud Spanner.
:param ddl_statements: The string list containing DDL for the new database.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:param operation_id: (Optional) The unique per database operation ID that can be
specified to implement idempotency check.
:return: None
"""
instance = self._get_client(project_id=project_id).instance(instance_id=instance_id)
if not instance.exists():
raise AirflowException(f"The instance {instance_id} does not exist in project {project_id} !")
database = instance.database(database_id=database_id)
try:
operation = database.update_ddl(ddl_statements=ddl_statements, operation_id=operation_id)
if operation:
result = operation.result()
self.log.info(result)
return
except AlreadyExists as e:
if e.code == 409 and operation_id in e.message:
self.log.info(
"Replayed update_ddl message - the operation id %s was already done before.",
operation_id,
)
return
except GoogleAPICallError as e:
self.log.error('An error occurred: %s. Exiting.', e.message)
raise e
@GoogleBaseHook.fallback_to_default_project_id
[docs] def delete_database(self, instance_id: str, database_id, project_id: str) -> bool:
"""
Drops a database in Cloud Spanner.
:param instance_id: The ID of the Cloud Spanner instance.
:param database_id: The ID of the database in Cloud Spanner.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
:return: True if everything succeeded
:rtype: bool
"""
instance = self._get_client(project_id=project_id).instance(instance_id=instance_id)
if not instance.exists():
raise AirflowException(f"The instance {instance_id} does not exist in project {project_id} !")
database = instance.database(database_id=database_id)
if not database.exists():
self.log.info(
"The database %s is already deleted from instance %s. Exiting.", database_id, instance_id
)
return False
try:
database.drop()
except GoogleAPICallError as e:
self.log.error('An error occurred: %s. Exiting.', e.message)
raise e
return True
@GoogleBaseHook.fallback_to_default_project_id
[docs] def execute_dml(
self,
instance_id: str,
database_id: str,
queries: List[str],
project_id: str,
) -> None:
"""
Executes an arbitrary DML query (INSERT, UPDATE, DELETE).
:param instance_id: The ID of the Cloud Spanner instance.
:param database_id: The ID of the database in Cloud Spanner.
:param queries: The queries to execute.
:param project_id: Optional, the ID of the Google Cloud project that owns the Cloud Spanner
database. If set to None or missing, the default project_id from the Google Cloud connection
is used.
"""
self._get_client(project_id=project_id).instance(instance_id=instance_id).database(
database_id=database_id
).run_in_transaction(lambda transaction: self._execute_sql_in_transaction(transaction, queries))
@staticmethod
def _execute_sql_in_transaction(transaction: Transaction, queries: List[str]):
for sql in queries:
transaction.execute_update(sql)