Source code for airflow.providers.google.cloud.sensors.gcs

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"""This module contains Google Cloud Storage sensors."""
from __future__ import annotations

import os
import textwrap
from datetime import datetime
from typing import TYPE_CHECKING, Callable, Sequence

from airflow.exceptions import AirflowException
from airflow.providers.google.cloud.hooks.gcs import GCSHook
from airflow.sensors.base import BaseSensorOperator, poke_mode_only

if TYPE_CHECKING:
    from airflow.utils.context import Context


[docs]class GCSObjectExistenceSensor(BaseSensorOperator): """ Checks for the existence of a file in Google Cloud Storage. :param bucket: The Google Cloud Storage bucket where the object is. :param object: The name of the object to check in the Google cloud storage bucket. :param google_cloud_conn_id: The connection ID to use when connecting to Google Cloud Storage. :param delegate_to: The account to impersonate using domain-wide delegation of authority, if any. For this to work, the service account making the request must have domain-wide delegation enabled. :param impersonation_chain: Optional service account to impersonate using short-term credentials, or chained list of accounts required to get the access_token of the last account in the list, which will be impersonated in the request. If set as a string, the account must grant the originating account the Service Account Token Creator IAM role. If set as a sequence, the identities from the list must grant Service Account Token Creator IAM role to the directly preceding identity, with first account from the list granting this role to the originating account (templated). """
[docs] template_fields: Sequence[str] = ( "bucket", "object", "impersonation_chain",
)
[docs] ui_color = "#f0eee4"
def __init__( self, *, bucket: str, object: str, google_cloud_conn_id: str = "google_cloud_default", delegate_to: str | None = None, impersonation_chain: str | Sequence[str] | None = None, **kwargs, ) -> None: super().__init__(**kwargs) self.bucket = bucket self.object = object self.google_cloud_conn_id = google_cloud_conn_id self.delegate_to = delegate_to self.impersonation_chain = impersonation_chain
[docs] def poke(self, context: Context) -> bool: self.log.info("Sensor checks existence of : %s, %s", self.bucket, self.object) hook = GCSHook( gcp_conn_id=self.google_cloud_conn_id, delegate_to=self.delegate_to, impersonation_chain=self.impersonation_chain, ) return hook.exists(self.bucket, self.object)
[docs]def ts_function(context): """ Default callback for the GoogleCloudStorageObjectUpdatedSensor. The default behaviour is check for the object being updated after the data interval's end, or execution_date + interval on Airflow versions prior to 2.2 (before AIP-39 implementation). """ try: return context["data_interval_end"] except KeyError: return context["dag"].following_schedule(context["execution_date"])
[docs]class GCSObjectUpdateSensor(BaseSensorOperator): """ Checks if an object is updated in Google Cloud Storage. :param bucket: The Google Cloud Storage bucket where the object is. :param object: The name of the object to download in the Google cloud storage bucket. :param ts_func: Callback for defining the update condition. The default callback returns execution_date + schedule_interval. The callback takes the context as parameter. :param google_cloud_conn_id: The connection ID to use when connecting to Google Cloud Storage. :param delegate_to: The account to impersonate using domain-wide delegation of authority, if any. For this to work, the service account making the request must have domain-wide delegation enabled. :param impersonation_chain: Optional service account to impersonate using short-term credentials, or chained list of accounts required to get the access_token of the last account in the list, which will be impersonated in the request. If set as a string, the account must grant the originating account the Service Account Token Creator IAM role. If set as a sequence, the identities from the list must grant Service Account Token Creator IAM role to the directly preceding identity, with first account from the list granting this role to the originating account (templated). """
[docs] template_fields: Sequence[str] = ( "bucket", "object", "impersonation_chain",
)
[docs] ui_color = "#f0eee4"
def __init__( self, bucket: str, object: str, ts_func: Callable = ts_function, google_cloud_conn_id: str = "google_cloud_default", delegate_to: str | None = None, impersonation_chain: str | Sequence[str] | None = None, **kwargs, ) -> None: super().__init__(**kwargs) self.bucket = bucket self.object = object self.ts_func = ts_func self.google_cloud_conn_id = google_cloud_conn_id self.delegate_to = delegate_to self.impersonation_chain = impersonation_chain
[docs] def poke(self, context: Context) -> bool: self.log.info("Sensor checks existence of : %s, %s", self.bucket, self.object) hook = GCSHook( gcp_conn_id=self.google_cloud_conn_id, delegate_to=self.delegate_to, impersonation_chain=self.impersonation_chain, ) return hook.is_updated_after(self.bucket, self.object, self.ts_func(context))
[docs]class GCSObjectsWithPrefixExistenceSensor(BaseSensorOperator): """ Checks for the existence of GCS objects at a given prefix, passing matches via XCom. When files matching the given prefix are found, the poke method's criteria will be fulfilled and the matching objects will be returned from the operator and passed through XCom for downstream tasks. :param bucket: The Google Cloud Storage bucket where the object is. :param prefix: The name of the prefix to check in the Google cloud storage bucket. :param google_cloud_conn_id: The connection ID to use when connecting to Google Cloud Storage. :param delegate_to: The account to impersonate using domain-wide delegation of authority, if any. For this to work, the service account making the request must have domain-wide delegation enabled. :param impersonation_chain: Optional service account to impersonate using short-term credentials, or chained list of accounts required to get the access_token of the last account in the list, which will be impersonated in the request. If set as a string, the account must grant the originating account the Service Account Token Creator IAM role. If set as a sequence, the identities from the list must grant Service Account Token Creator IAM role to the directly preceding identity, with first account from the list granting this role to the originating account (templated). """
[docs] template_fields: Sequence[str] = ( "bucket", "prefix", "impersonation_chain",
)
[docs] ui_color = "#f0eee4"
def __init__( self, bucket: str, prefix: str, google_cloud_conn_id: str = "google_cloud_default", delegate_to: str | None = None, impersonation_chain: str | Sequence[str] | None = None, **kwargs, ) -> None: super().__init__(**kwargs) self.bucket = bucket self.prefix = prefix self.google_cloud_conn_id = google_cloud_conn_id self.delegate_to = delegate_to self._matches: list[str] = [] self.impersonation_chain = impersonation_chain
[docs] def poke(self, context: Context) -> bool: self.log.info("Sensor checks existence of objects: %s, %s", self.bucket, self.prefix) hook = GCSHook( gcp_conn_id=self.google_cloud_conn_id, delegate_to=self.delegate_to, impersonation_chain=self.impersonation_chain, ) self._matches = hook.list(self.bucket, prefix=self.prefix) return bool(self._matches)
[docs] def execute(self, context: Context) -> list[str]: """Overridden to allow matches to be passed""" super().execute(context) return self._matches
[docs]def get_time(): """ This is just a wrapper of datetime.datetime.now to simplify mocking in the unittests. """ return datetime.now()
@poke_mode_only
[docs]class GCSUploadSessionCompleteSensor(BaseSensorOperator): """ Checks for changes in the number of objects at prefix in Google Cloud Storage bucket and returns True if the inactivity period has passed with no increase in the number of objects. Note, this sensor will not behave correctly in reschedule mode, as the state of the listed objects in the GCS bucket will be lost between rescheduled invocations. :param bucket: The Google Cloud Storage bucket where the objects are. expected. :param prefix: The name of the prefix to check in the Google cloud storage bucket. :param inactivity_period: The total seconds of inactivity to designate an upload session is over. Note, this mechanism is not real time and this operator may not return until a poke_interval after this period has passed with no additional objects sensed. :param min_objects: The minimum number of objects needed for upload session to be considered valid. :param previous_objects: The set of object ids found during the last poke. :param allow_delete: Should this sensor consider objects being deleted between pokes valid behavior. If true a warning message will be logged when this happens. If false an error will be raised. :param google_cloud_conn_id: The connection ID to use when connecting to Google Cloud Storage. :param delegate_to: The account to impersonate using domain-wide delegation of authority, if any. For this to work, the service account making the request must have domain-wide delegation enabled. :param impersonation_chain: Optional service account to impersonate using short-term credentials, or chained list of accounts required to get the access_token of the last account in the list, which will be impersonated in the request. If set as a string, the account must grant the originating account the Service Account Token Creator IAM role. If set as a sequence, the identities from the list must grant Service Account Token Creator IAM role to the directly preceding identity, with first account from the list granting this role to the originating account (templated). """
[docs] template_fields: Sequence[str] = ( "bucket", "prefix", "impersonation_chain",
)
[docs] ui_color = "#f0eee4"
def __init__( self, bucket: str, prefix: str, inactivity_period: float = 60 * 60, min_objects: int = 1, previous_objects: set[str] | None = None, allow_delete: bool = True, google_cloud_conn_id: str = "google_cloud_default", delegate_to: str | None = None, impersonation_chain: str | Sequence[str] | None = None, **kwargs, ) -> None: super().__init__(**kwargs) self.bucket = bucket self.prefix = prefix if inactivity_period < 0: raise ValueError("inactivity_period must be non-negative") self.inactivity_period = inactivity_period self.min_objects = min_objects self.previous_objects = previous_objects if previous_objects else set() self.inactivity_seconds = 0 self.allow_delete = allow_delete self.google_cloud_conn_id = google_cloud_conn_id self.delegate_to = delegate_to self.last_activity_time = None self.impersonation_chain = impersonation_chain self.hook: GCSHook | None = None def _get_gcs_hook(self) -> GCSHook | None: if not self.hook: self.hook = GCSHook( gcp_conn_id=self.google_cloud_conn_id, delegate_to=self.delegate_to, impersonation_chain=self.impersonation_chain, ) return self.hook
[docs] def is_bucket_updated(self, current_objects: set[str]) -> bool: """ Checks whether new objects have been uploaded and the inactivity_period has passed and updates the state of the sensor accordingly. :param current_objects: set of object ids in bucket during last poke. """ current_num_objects = len(current_objects) if current_objects > self.previous_objects: # When new objects arrived, reset the inactivity_seconds # and update previous_objects for the next poke. self.log.info( "New objects found at %s resetting last_activity_time.", os.path.join(self.bucket, self.prefix), ) self.log.debug("New objects: %s", "\n".join(current_objects - self.previous_objects)) self.last_activity_time = get_time() self.inactivity_seconds = 0 self.previous_objects = current_objects return False if self.previous_objects - current_objects: # During the last poke interval objects were deleted. if self.allow_delete: self.previous_objects = current_objects self.last_activity_time = get_time() self.log.warning( textwrap.dedent( """\ Objects were deleted during the last poke interval. Updating the file counter and resetting last_activity_time. %s\ """ ), self.previous_objects - current_objects, ) return False raise AirflowException( "Illegal behavior: objects were deleted in " f"{os.path.join(self.bucket, self.prefix)} between pokes." ) if self.last_activity_time: self.inactivity_seconds = (get_time() - self.last_activity_time).total_seconds() else: # Handles the first poke where last inactivity time is None. self.last_activity_time = get_time() self.inactivity_seconds = 0 if self.inactivity_seconds >= self.inactivity_period: path = os.path.join(self.bucket, self.prefix) if current_num_objects >= self.min_objects: self.log.info( textwrap.dedent( """\ SUCCESS: Sensor found %s objects at %s. Waited at least %s seconds, with no new objects dropped. """ ), current_num_objects, path, self.inactivity_period, ) return True self.log.error("FAILURE: Inactivity Period passed, not enough objects found in %s", path) return False return False
[docs] def poke(self, context: Context) -> bool: return self.is_bucket_updated( set(self._get_gcs_hook().list(self.bucket, prefix=self.prefix)) # type: ignore[union-attr]
)

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