Source code for

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from __future__ import annotations

import logging
import os
import shutil
from functools import cached_property
from pathlib import Path
from typing import TYPE_CHECKING, Collection

# not sure why but mypy complains on missing `storage` but it is clearly there and is importable
from import storage  # type: ignore[attr-defined]
from packaging.version import Version

from airflow.configuration import conf
from airflow.exceptions import AirflowNotFoundException
from import GCSHook, _parse_gcs_url
from import get_credentials_and_project_id
from import CLIENT_INFO
from airflow.utils.log.file_task_handler import FileTaskHandler
from airflow.utils.log.logging_mixin import LoggingMixin

    from airflow.models.taskinstance import TaskInstance

_DEFAULT_SCOPESS = frozenset(

[docs]logger = logging.getLogger(__name__)
[docs]def get_default_delete_local_copy(): """Load delete_local_logs conf if Airflow version > 2.6 and return False if not. TODO: delete this function when min airflow version >= 2.6. """ from airflow.version import version if Version(version) < Version("2.6"): return False return conf.getboolean("logging", "delete_local_logs")
[docs]class GCSTaskHandler(FileTaskHandler, LoggingMixin): """ GCSTaskHandler is a python log handler that handles and reads task instance logs. It extends airflow FileTaskHandler and uploads to and reads from GCS remote storage. Upon log reading failure, it reads from host machine's local disk. :param base_log_folder: Base log folder to place logs. :param gcs_log_folder: Path to a remote location where logs will be saved. It must have the prefix ``gs://``. For example: ``gs://bucket/remote/log/location`` :param filename_template: template filename string :param gcp_key_path: Path to Google Cloud Service Account file (JSON). Mutually exclusive with gcp_keyfile_dict. If omitted, authorization based on `the Application Default Credentials <>`__ will be used. :param gcp_keyfile_dict: Dictionary of keyfile parameters. Mutually exclusive with gcp_key_path. :param gcp_scopes: Comma-separated string containing OAuth2 scopes :param project_id: Project ID to read the secrets from. If not passed, the project ID from credentials will be used. :param delete_local_copy: Whether local log files should be deleted after they are downloaded when using remote logging """
[docs] trigger_should_wrap = True
def __init__( self, *, base_log_folder: str, gcs_log_folder: str, filename_template: str | None = None, gcp_key_path: str | None = None, gcp_keyfile_dict: dict | None = None, gcp_scopes: Collection[str] | None = _DEFAULT_SCOPESS, project_id: str | None = None, **kwargs, ): super().__init__(base_log_folder, filename_template) self.handler: logging.FileHandler | None = None self.remote_base = gcs_log_folder self.log_relative_path = "" self.closed = False self.upload_on_close = True self.gcp_key_path = gcp_key_path self.gcp_keyfile_dict = gcp_keyfile_dict self.scopes = gcp_scopes self.project_id = project_id self.delete_local_copy = ( kwargs["delete_local_copy"] if "delete_local_copy" in kwargs else get_default_delete_local_copy() ) @cached_property
[docs] def hook(self) -> GCSHook | None: """Returns GCSHook if remote_log_conn_id configured.""" conn_id = conf.get("logging", "remote_log_conn_id", fallback=None) if conn_id: try: return GCSHook(gcp_conn_id=conn_id) except AirflowNotFoundException: pass return None
[docs] def client(self) -> storage.Client: """Returns GCS Client.""" if self.hook: credentials, project_id = self.hook.get_credentials_and_project_id() else: credentials, project_id = get_credentials_and_project_id( key_path=self.gcp_key_path, keyfile_dict=self.gcp_keyfile_dict, scopes=self.scopes, disable_logging=True, ) return storage.Client( credentials=credentials, client_info=CLIENT_INFO, project=self.project_id if self.project_id else project_id, )
[docs] def set_context(self, ti: TaskInstance, *, identifier: str | None = None) -> None: # todo: remove-at-min-airflow-version-2.8 # after Airflow 2.8 can always pass `identifier` if getattr(super(), "supports_task_context_logging", False): super().set_context(ti, identifier=identifier) else: super().set_context(ti) # Log relative path is used to construct local and remote # log path to upload log files into GCS and read from the # remote location. if TYPE_CHECKING: assert self.handler is not None full_path = self.handler.baseFilename self.log_relative_path = Path(full_path).relative_to(self.local_base).as_posix() is_trigger_log_context = getattr(ti, "is_trigger_log_context", False) self.upload_on_close = is_trigger_log_context or not getattr(ti, "raw", None)
[docs] def close(self): """Close and upload local log file to remote storage GCS.""" # When application exit, system shuts down all handlers by # calling close method. Here we check if logger is already # closed to prevent uploading the log to remote storage multiple # times when `logging.shutdown` is called. if self.closed: return super().close() if not self.upload_on_close: return local_loc = os.path.join(self.local_base, self.log_relative_path) remote_loc = os.path.join(self.remote_base, self.log_relative_path) if os.path.exists(local_loc): # read log and remove old logs to get just the latest additions with open(local_loc) as logfile: log = gcs_write = self.gcs_write(log, remote_loc) if gcs_write and self.delete_local_copy: shutil.rmtree(os.path.dirname(local_loc)) # Mark closed so we don't double write if close is called twice self.closed = True
def _add_message(self, msg): filename, lineno, func, stackinfo = logger.findCaller() record = logging.LogRecord("", logging.INFO, filename, lineno, msg + "\n", None, None, func=func) return self.format(record) def _read_remote_logs(self, ti, try_number, metadata=None) -> tuple[list[str], list[str]]: # Explicitly getting log relative path is necessary because this method # is called from webserver from TaskLogReader, where we don't call set_context # and can read logs for different TIs in each request messages = [] logs = [] worker_log_relative_path = self._render_filename(ti, try_number) remote_loc = os.path.join(self.remote_base, worker_log_relative_path) uris = [] bucket, prefix = _parse_gcs_url(remote_loc) blobs = list(self.client.list_blobs(bucket_or_name=bucket, prefix=prefix)) if blobs: uris = [f"gs://{bucket}/{}" for b in blobs] messages.extend(["Found remote logs:", *[f" * {x}" for x in sorted(uris)]]) else: messages.append(f"No logs found in GCS; ti=%s {ti}") try: for key in sorted(uris): blob = storage.Blob.from_string(key, self.client) remote_log = blob.download_as_bytes().decode() if remote_log: logs.append(remote_log) except Exception as e: messages.append(f"Unable to read remote log {e}") return messages, logs def _read(self, ti, try_number, metadata=None): """ Read logs of given task instance and try_number from GCS. If failed, read the log from task instance host machine. todo: when min airflow version >= 2.6, remove this method :param ti: task instance object :param try_number: task instance try_number to read logs from :param metadata: log metadata, can be used for steaming log reading and auto-tailing. """ if hasattr(super(), "_read_remote_logs"): # from Airflow 2.6, we don't implement the `_read` method. # if parent has _read_remote_logs, we're >= 2.6 return super()._read(ti, try_number, metadata) messages, logs = self._read_remote_logs(ti, try_number, metadata) if not logs: return super()._read(ti, try_number, metadata) return "".join([f"*** {x}\n" for x in messages]) + "\n".join(logs), {"end_of_log": True}
[docs] def gcs_write(self, log, remote_log_location) -> bool: """ Write the log to the remote location and return `True`; fail silently and return `False` on error. :param log: the log to write to the remote_log_location :param remote_log_location: the log's location in remote storage :return: whether the log is successfully written to remote location or not. """ try: blob = storage.Blob.from_string(remote_log_location, self.client) old_log = blob.download_as_bytes().decode() log = f"{old_log}\n{log}" if old_log else log except Exception as e: if not self.no_log_found(e): log += self._add_message( f"Error checking for previous log; if exists, may be overwritten: {e}" ) self.log.warning("Error checking for previous log: %s", e) try: blob = storage.Blob.from_string(remote_log_location, self.client) blob.upload_from_string(log, content_type="text/plain") except Exception as e: self.log.error("Could not write logs to %s: %s", remote_log_location, e) return False return True
@staticmethod def no_log_found(exc): """ Given exception, determine whether it is result of log not found. :meta private: """ if (exc.args and isinstance(exc.args[0], str) and "No such object" in exc.args[0]) or getattr( exc, "resp", {} ).get("status") == "404": return True return False

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