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"""Handler that integrates with Stackdriver"""
import logging
import sys
from typing import Collection, Dict, List, Optional, Tuple, Type, Union
from urllib.parse import urlencode
from airflow.providers.google.common.consts import CLIENT_INFO
if sys.version_info >= (3, 8):
from functools import cached_property
else:
from cached_property import cached_property
from google.auth.credentials import Credentials
from google.cloud import logging as gcp_logging
from google.cloud.logging import Resource
from google.cloud.logging.handlers.transports import BackgroundThreadTransport, Transport
from google.cloud.logging_v2.services.logging_service_v2 import LoggingServiceV2Client
from google.cloud.logging_v2.types import ListLogEntriesRequest, ListLogEntriesResponse
from airflow.models import TaskInstance
from airflow.providers.google.cloud.utils.credentials_provider import get_credentials_and_project_id
[docs]DEFAULT_LOGGER_NAME = "airflow"
_GLOBAL_RESOURCE = Resource(type="global", labels={})
_DEFAULT_SCOPESS = frozenset(
["https://www.googleapis.com/auth/logging.read", "https://www.googleapis.com/auth/logging.write"]
)
[docs]class StackdriverTaskHandler(logging.Handler):
"""Handler that directly makes Stackdriver logging API calls.
This is a Python standard ``logging`` handler using that can be used to
route Python standard logging messages directly to the Stackdriver
Logging API.
It can also be used to save logs for executing tasks. To do this, you should set as a handler with
the name "tasks". In this case, it will also be used to read the log for display in Web UI.
This handler supports both an asynchronous and synchronous transport.
:param gcp_key_path: Path to Google Cloud Credential JSON file.
If omitted, authorization based on `the Application Default Credentials
<https://cloud.google.com/docs/authentication/production#finding_credentials_automatically>`__ will
be used.
:param scopes: OAuth scopes for the credentials,
:param name: the name of the custom log in Stackdriver Logging. Defaults
to 'airflow'. The name of the Python logger will be represented
in the ``python_logger`` field.
:param transport: Class for creating new transport objects. It should
extend from the base :class:`google.cloud.logging.handlers.Transport` type and
implement :meth`google.cloud.logging.handlers.Transport.send`. Defaults to
:class:`google.cloud.logging.handlers.BackgroundThreadTransport`. The other
option is :class:`google.cloud.logging.handlers.SyncTransport`.
:param resource: (Optional) Monitored resource of the entry, defaults
to the global resource type.
:param labels: (Optional) Mapping of labels for the entry.
"""
[docs] LABEL_TASK_ID = "task_id"
[docs] LABEL_DAG_ID = "dag_id"
[docs] LABEL_EXECUTION_DATE = "execution_date"
[docs] LABEL_TRY_NUMBER = "try_number"
[docs] LOG_VIEWER_BASE_URL = "https://console.cloud.google.com/logs/viewer"
[docs] LOG_NAME = 'Google Stackdriver'
def __init__(
self,
gcp_key_path: Optional[str] = None,
scopes: Optional[Collection[str]] = _DEFAULT_SCOPESS,
name: str = DEFAULT_LOGGER_NAME,
transport: Type[Transport] = BackgroundThreadTransport,
resource: Resource = _GLOBAL_RESOURCE,
labels: Optional[Dict[str, str]] = None,
):
super().__init__()
self.gcp_key_path: Optional[str] = gcp_key_path
self.scopes: Optional[Collection[str]] = scopes
self.name: str = name
self.transport_type: Type[Transport] = transport
self.resource: Resource = resource
self.labels: Optional[Dict[str, str]] = labels
self.task_instance_labels: Optional[Dict[str, str]] = {}
self.task_instance_hostname = 'default-hostname'
@cached_property
def _credentials_and_project(self) -> Tuple[Credentials, str]:
credentials, project = get_credentials_and_project_id(
key_path=self.gcp_key_path, scopes=self.scopes, disable_logging=True
)
return credentials, project
@property
def _client(self) -> gcp_logging.Client:
"""The Cloud Library API client"""
credentials, project = self._credentials_and_project
client = gcp_logging.Client(
credentials=credentials,
project=project,
client_info=CLIENT_INFO,
)
return client
@property
def _logging_service_client(self) -> LoggingServiceV2Client:
"""The Cloud logging service v2 client."""
credentials, _ = self._credentials_and_project
client = LoggingServiceV2Client(
credentials=credentials,
client_info=CLIENT_INFO,
)
return client
@cached_property
def _transport(self) -> Transport:
"""Object responsible for sending data to Stackdriver"""
# The Transport object is badly defined (no init) but in the docs client/name as constructor
# arguments are a requirement for any class that derives from Transport class, hence ignore:
return self.transport_type(self._client, self.name) # type: ignore[call-arg]
[docs] def emit(self, record: logging.LogRecord) -> None:
"""Actually log the specified logging record.
:param record: The record to be logged.
"""
message = self.format(record)
labels: Optional[Dict[str, str]]
if self.labels and self.task_instance_labels:
labels = {}
labels.update(self.labels)
labels.update(self.task_instance_labels)
elif self.labels:
labels = self.labels
elif self.task_instance_labels:
labels = self.task_instance_labels
else:
labels = None
self._transport.send(record, message, resource=self.resource, labels=labels)
[docs] def set_context(self, task_instance: TaskInstance) -> None:
"""
Configures the logger to add information with information about the current task
:param task_instance: Currently executed task
"""
self.task_instance_labels = self._task_instance_to_labels(task_instance)
self.task_instance_hostname = task_instance.hostname
[docs] def read(
self, task_instance: TaskInstance, try_number: Optional[int] = None, metadata: Optional[Dict] = None
) -> Tuple[List[Tuple[Tuple[str, str]]], List[Dict[str, Union[str, bool]]]]:
"""
Read logs of given task instance from Stackdriver logging.
:param task_instance: task instance object
:param try_number: task instance try_number to read logs from. If None
it returns all logs
:param metadata: log metadata. It is used for steaming log reading and auto-tailing.
:return: a tuple of (
list of (one element tuple with two element tuple - hostname and logs)
and list of metadata)
:rtype: Tuple[List[Tuple[Tuple[str, str]]], List[Dict[str, str]]]
"""
if try_number is not None and try_number < 1:
logs = f"Error fetching the logs. Try number {try_number} is invalid."
return [((self.task_instance_hostname, logs),)], [{"end_of_log": "true"}]
if not metadata:
metadata = {}
ti_labels = self._task_instance_to_labels(task_instance)
if try_number is not None:
ti_labels[self.LABEL_TRY_NUMBER] = str(try_number)
else:
del ti_labels[self.LABEL_TRY_NUMBER]
log_filter = self._prepare_log_filter(ti_labels)
next_page_token = metadata.get("next_page_token", None)
all_pages = 'download_logs' in metadata and metadata['download_logs']
messages, end_of_log, next_page_token = self._read_logs(log_filter, next_page_token, all_pages)
new_metadata: Dict[str, Union[str, bool]] = {"end_of_log": end_of_log}
if next_page_token:
new_metadata['next_page_token'] = next_page_token
return [((self.task_instance_hostname, messages),)], [new_metadata]
def _prepare_log_filter(self, ti_labels: Dict[str, str]) -> str:
"""
Prepares the filter that chooses which log entries to fetch.
More information:
https://cloud.google.com/logging/docs/reference/v2/rest/v2/entries/list#body.request_body.FIELDS.filter
https://cloud.google.com/logging/docs/view/advanced-queries
:param ti_labels: Task Instance's labels that will be used to search for logs
:return: logs filter
"""
def escape_label_key(key: str) -> str:
return f'"{key}"' if "." in key else key
def escale_label_value(value: str) -> str:
escaped_value = value.replace("\\", "\\\\").replace('"', '\\"')
return f'"{escaped_value}"'
_, project = self._credentials_and_project
log_filters = [
f'resource.type={escale_label_value(self.resource.type)}',
f'logName="projects/{project}/logs/{self.name}"',
]
for key, value in self.resource.labels.items():
log_filters.append(f'resource.labels.{escape_label_key(key)}={escale_label_value(value)}')
for key, value in ti_labels.items():
log_filters.append(f'labels.{escape_label_key(key)}={escale_label_value(value)}')
return "\n".join(log_filters)
def _read_logs(
self, log_filter: str, next_page_token: Optional[str], all_pages: bool
) -> Tuple[str, bool, Optional[str]]:
"""
Sends requests to the Stackdriver service and downloads logs.
:param log_filter: Filter specifying the logs to be downloaded.
:param next_page_token: The token of the page from which the log download will start.
If None is passed, it will start from the first page.
:param all_pages: If True is passed, all subpages will be downloaded. Otherwise, only the first
page will be downloaded
:return: A token that contains the following items:
* string with logs
* Boolean value describing whether there are more logs,
* token of the next page
:rtype: Tuple[str, bool, str]
"""
messages = []
new_messages, next_page_token = self._read_single_logs_page(
log_filter=log_filter,
page_token=next_page_token,
)
messages.append(new_messages)
if all_pages:
while next_page_token:
new_messages, next_page_token = self._read_single_logs_page(
log_filter=log_filter, page_token=next_page_token
)
messages.append(new_messages)
if not messages:
break
end_of_log = True
next_page_token = None
else:
end_of_log = not bool(next_page_token)
return "\n".join(messages), end_of_log, next_page_token
def _read_single_logs_page(self, log_filter: str, page_token: Optional[str] = None) -> Tuple[str, str]:
"""
Sends requests to the Stackdriver service and downloads single pages with logs.
:param log_filter: Filter specifying the logs to be downloaded.
:param page_token: The token of the page to be downloaded. If None is passed, the first page will be
downloaded.
:return: Downloaded logs and next page token
:rtype: Tuple[str, str]
"""
_, project = self._credentials_and_project
request = ListLogEntriesRequest(
resource_names=[f'projects/{project}'],
filter=log_filter,
page_token=page_token,
order_by='timestamp asc',
page_size=1000,
)
response = self._logging_service_client.list_log_entries(request=request)
page: ListLogEntriesResponse = next(response.pages)
messages = []
for entry in page.entries:
if "message" in entry.json_payload:
messages.append(entry.json_payload["message"])
return "\n".join(messages), page.next_page_token
@classmethod
def _task_instance_to_labels(cls, ti: TaskInstance) -> Dict[str, str]:
return {
cls.LABEL_TASK_ID: ti.task_id,
cls.LABEL_DAG_ID: ti.dag_id,
cls.LABEL_EXECUTION_DATE: str(ti.execution_date.isoformat()),
cls.LABEL_TRY_NUMBER: str(ti.try_number),
}
@property
[docs] def log_name(self):
"""Return log name."""
return self.LOG_NAME
@cached_property
def _resource_path(self):
segments = [self.resource.type]
for key, value in self.resource.labels:
segments += [key]
segments += [value]
return "/".join(segments)
[docs] def get_external_log_url(self, task_instance: TaskInstance, try_number: int) -> str:
"""
Creates an address for an external log collecting service.
:param task_instance: task instance object
:param try_number: task instance try_number to read logs from.
:return: URL to the external log collection service
:rtype: str
"""
_, project_id = self._credentials_and_project
ti_labels = self._task_instance_to_labels(task_instance)
ti_labels[self.LABEL_TRY_NUMBER] = str(try_number)
log_filter = self._prepare_log_filter(ti_labels)
url_query_string = {
'project': project_id,
'interval': 'NO_LIMIT',
'resource': self._resource_path,
'advancedFilter': log_filter,
}
url = f"{self.LOG_VIEWER_BASE_URL}?{urlencode(url_query_string)}"
return url
[docs] def close(self) -> None:
self._transport.flush()
