ismailsimsek commented on code in PR #46621: URL: https://github.com/apache/airflow/pull/46621#discussion_r2104641880
########## providers/amazon/src/airflow/providers/amazon/aws/bundles/s3.py: ########## @@ -0,0 +1,214 @@ +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +from __future__ import annotations + +import os +from pathlib import Path + +import structlog + +log = structlog.get_logger(__name__) + +from airflow.dag_processing.bundles.base import BaseDagBundle +from airflow.exceptions import AirflowException +from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook +from airflow.providers.amazon.aws.hooks.s3 import S3Hook + + +class S3DagBundle(BaseDagBundle): + """ + S3 DAG bundle - exposes a directory in S3 as a DAG bundle. + + This allows Airflow to load DAGs directly from an S3 bucket. + + :param aws_conn_id: Airflow connection ID for AWS. Defaults to AwsBaseHook.default_conn_name. + :param bucket_name: The name of the S3 bucket containing the DAG files. + :param prefix: Optional subdirectory within the S3 bucket where the DAGs are stored. + If None, DAGs are assumed to be at the root of the bucket (Optional). + """ + + supports_versioning = False + + def __init__( + self, + *, + aws_conn_id: str = AwsBaseHook.default_conn_name, + bucket_name: str, + prefix: str = "", + **kwargs, + ) -> None: + super().__init__(**kwargs) + self.aws_conn_id = aws_conn_id + self.bucket_name = bucket_name + self.prefix = prefix + # Local path where S3 DAGs are downloaded. + self.s3_dags_root_dir: Path = self.base_dir.joinpath("s3") + # Local path where S3 DAGs are downloaded for current config. + self.s3_dags_dir: Path = self.s3_dags_root_dir.joinpath(self.name) + + self._log = log.bind( + bundle_name=self.name, + version=self.version, + bucket_name=self.bucket_name, + prefix=self.prefix, + aws_conn_id=self.aws_conn_id, + ) + + try: + self.s3_hook: S3Hook = S3Hook(aws_conn_id=self.aws_conn_id) # Initialize S3 hook. + except AirflowException as e: + self._log.warning("Could not create S3Hook for connection %s: %s", self.aws_conn_id, e) + + def _initialize(self): + with self.lock(): + if not self.s3_dags_dir.exists(): + self._log.info("Creating local DAGs directory: %s", self.s3_dags_dir) + os.makedirs(self.s3_dags_dir) + + if not self.s3_dags_dir.is_dir(): + raise AirflowException(f"Local DAGs path: {self.s3_dags_dir} is not a directory.") + + if not self.s3_hook.check_for_bucket(bucket_name=self.bucket_name): + raise AirflowException(f"S3 bucket '{self.bucket_name}' does not exist.") + + if self.prefix: + # don't check when prefix is "" + if not self.s3_hook.check_for_prefix( + bucket_name=self.bucket_name, prefix=self.prefix, delimiter="/" + ): + raise AirflowException( + f"S3 prefix 's3://{self.bucket_name}/{self.prefix}' does not exist." + ) + + self._download_s3_dags() + self.refresh() + + def initialize(self) -> None: + self._initialize() + super().initialize() + + def _delete_stale_local_files(self, current_s3_objects: list[Path]): + current_s3_keys = {key for key in current_s3_objects} + + for item in self.s3_dags_dir.iterdir(): + item: Path # type: ignore[no-redef] + absolute_item_path = item.resolve() + + if absolute_item_path not in current_s3_keys: + try: + if item.is_file(): + item.unlink(missing_ok=True) + self._log.debug("Deleted stale local file: %s", item) + elif item.is_dir(): + # delete only when the folder is empty + if not os.listdir(item): + item.rmdir() + self._log.debug("Deleted stale empty directory: %s", item) + else: + self._log.debug("Skipping stale item of unknown type: %s", item) + except OSError as e: + self._log.error("Error deleting stale item %s: %s", item, e) + raise e + + def _download_s3_object_if_changed(self, s3_bucket, s3_object, local_target_path: Path): + should_download = False + download_msg = "" + if not local_target_path.exists(): + should_download = True + download_msg = f"Local file {local_target_path} does not exist." + else: + local_stats = local_target_path.stat() + + if s3_object.size != local_stats.st_size: + should_download = True + download_msg = ( + f"S3 object size ({s3_object.size}) and local file size ({local_stats.st_size}) differ." + ) + + s3_last_modified = s3_object.last_modified + if local_stats.st_mtime < s3_last_modified.microsecond: + should_download = True + download_msg = f"S3 object last modified ({s3_last_modified.microsecond}) and local file last modified ({local_stats.st_mtime}) differ." + + if should_download: + s3_bucket.download_file(s3_object.key, local_target_path) + self._log.debug( + "%s Downloaded %s to %s", download_msg, s3_object.key, local_target_path.as_posix() + ) + else: + self._log.debug( + "Local file %s is up-to-date with S3 object %s. Skipping download.", + local_target_path.as_posix(), + s3_object.key, + ) + + def _download_s3_dags(self): + """Download DAG files from the S3 bucket to the local directory.""" + self._log.debug( + "Downloading DAGs from s3://%s/%s to %s", self.bucket_name, self.prefix, self.s3_dags_dir + ) + local_s3_objects = [] + s3_bucket = self.s3_hook.get_bucket(self.bucket_name) + for obj in s3_bucket.objects.filter(Prefix=self.prefix): + obj_path = Path(obj.key) + local_target_path = self.s3_dags_dir.joinpath(obj_path.relative_to(self.prefix)) + if not local_target_path.parent.exists(): + local_target_path.parent.mkdir(parents=True, exist_ok=True) + self._log.debug("Created local directory: %s", local_target_path.parent) + self._download_s3_object_if_changed( + s3_bucket=s3_bucket, s3_object=obj, local_target_path=local_target_path + ) + local_s3_objects.append(local_target_path) + + self._delete_stale_local_files(current_s3_objects=local_s3_objects) + + def __repr__(self): + return ( + f"<S3DagBundle(" + f"name={self.name!r}, " + f"bucket_name={self.bucket_name!r}, " + f"prefix={self.prefix!r}, " + f"version={self.version!r}" + f")>" + ) + + def get_current_version(self) -> str | None: + """Return the current version of the DAG bundle. Currently not supported.""" + return None + + @property + def path(self) -> Path: + """Return the local path to the DAG files.""" + return self.s3_dags_dir # Path where DAGs are downloaded. + + def refresh(self) -> None: + """Refresh the DAG bundle by re-downloading the DAGs from S3.""" + if self.version: + raise AirflowException("Refreshing a specific version is not supported") + + with self.lock(): + self._download_s3_dags() + + def view_url(self, version: str | None = None) -> str | None: + """Return a URL for viewing the DAGs in S3. Currently, versioning is not supported.""" + if self.version: + raise AirflowException("S3 url with version is not supported") + + presigned_url = self.s3_hook.generate_presigned_url( Review Comment: Changed to normal url -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. 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