#
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# to you under the Apache License, Version 2.0 (the
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#
# 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
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# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations
import logging
import sys
import warnings
from collections import defaultdict
from datetime import datetime
from operator import attrgetter
from time import time
from typing import TYPE_CHECKING, List, Tuple
from urllib.parse import quote
# Using `from elasticsearch import *` would break elasticsearch mocking used in unit test.
import elasticsearch
import pendulum
from elasticsearch_dsl import Search
from airflow.configuration import conf
from airflow.models.dagrun import DagRun
from airflow.models.taskinstance import TaskInstance
from airflow.providers.elasticsearch.log.es_json_formatter import ElasticsearchJSONFormatter
from airflow.utils import timezone
from airflow.utils.log.file_task_handler import FileTaskHandler
from airflow.utils.log.logging_mixin import ExternalLoggingMixin, LoggingMixin
from airflow.utils.session import create_session
[docs]LOG_LINE_DEFAULTS = {'exc_text': '', 'stack_info': ''}
# Elasticsearch hosted log type
[docs]EsLogMsgType = List[Tuple[str, str]]
# Compatibility: Airflow 2.3.3 and up uses this method, which accesses the
# LogTemplate model to record the log ID template used. If this function does
# not exist, the task handler should use the log_id_template attribute instead.
[docs]USE_PER_RUN_LOG_ID = hasattr(DagRun, "get_log_template")
[docs]class ElasticsearchTaskHandler(FileTaskHandler, ExternalLoggingMixin, LoggingMixin):
"""
ElasticsearchTaskHandler is a python log handler that
reads logs from Elasticsearch. Note that Airflow does not handle the indexing
of logs into Elasticsearch. Instead, Airflow flushes logs
into local files. Additional software setup is required
to index the logs into Elasticsearch, such as using
Filebeat and Logstash.
To efficiently query and sort Elasticsearch results, this handler assumes each
log message has a field `log_id` consists of ti primary keys:
`log_id = {dag_id}-{task_id}-{execution_date}-{try_number}`
Log messages with specific log_id are sorted based on `offset`,
which is a unique integer indicates log message's order.
Timestamps here are unreliable because multiple log messages
might have the same timestamp.
"""
[docs] MAX_LINE_PER_PAGE = 1000
[docs] LOG_NAME = 'Elasticsearch'
def __init__(
self,
base_log_folder: str,
end_of_log_mark: str,
write_stdout: bool,
json_format: bool,
json_fields: str,
host_field: str = "host",
offset_field: str = "offset",
host: str = "localhost:9200",
frontend: str = "localhost:5601",
es_kwargs: dict | None = conf.getsection("elasticsearch_configs"),
*,
filename_template: str | None = None,
log_id_template: str | None = None,
):
"""
:param base_log_folder: base folder to store logs locally
:param log_id_template: log id template
:param host: Elasticsearch host name
"""
es_kwargs = es_kwargs or {}
super().__init__(base_log_folder, filename_template)
self.closed = False
self.client = elasticsearch.Elasticsearch(host.split(';'), **es_kwargs) # type: ignore[attr-defined]
if USE_PER_RUN_LOG_ID and log_id_template is not None:
warnings.warn(
"Passing log_id_template to ElasticsearchTaskHandler is deprecated and has no effect",
DeprecationWarning,
)
self.log_id_template = log_id_template # Only used on Airflow < 2.3.2.
self.frontend = frontend
self.mark_end_on_close = True
self.end_of_log_mark = end_of_log_mark.strip()
self.write_stdout = write_stdout
self.json_format = json_format
self.json_fields = [label.strip() for label in json_fields.split(",")]
self.host_field = host_field
self.offset_field = offset_field
self.context_set = False
self.formatter: logging.Formatter
self.handler: logging.FileHandler | logging.StreamHandler # type: ignore[assignment]
def _render_log_id(self, ti: TaskInstance, try_number: int) -> str:
with create_session() as session:
dag_run = ti.get_dagrun(session=session)
if USE_PER_RUN_LOG_ID:
log_id_template = dag_run.get_log_template(session=session).elasticsearch_id
else:
log_id_template = self.log_id_template
try:
dag = ti.task.dag
except AttributeError: # ti.task is not always set.
data_interval = (dag_run.data_interval_start, dag_run.data_interval_end)
else:
if TYPE_CHECKING:
assert dag is not None
data_interval = dag.get_run_data_interval(dag_run)
if self.json_format:
data_interval_start = self._clean_date(data_interval[0])
data_interval_end = self._clean_date(data_interval[1])
execution_date = self._clean_date(dag_run.execution_date)
else:
if data_interval[0]:
data_interval_start = data_interval[0].isoformat()
else:
data_interval_start = ""
if data_interval[1]:
data_interval_end = data_interval[1].isoformat()
else:
data_interval_end = ""
execution_date = dag_run.execution_date.isoformat()
return log_id_template.format(
dag_id=ti.dag_id,
task_id=ti.task_id,
run_id=getattr(ti, "run_id", ""),
data_interval_start=data_interval_start,
data_interval_end=data_interval_end,
execution_date=execution_date,
try_number=try_number,
map_index=getattr(ti, "map_index", ""),
)
@staticmethod
def _clean_date(value: datetime | None) -> str:
"""
Clean up a date value so that it is safe to query in elasticsearch
by removing reserved characters.
https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html#_reserved_characters
"""
if value is None:
return ""
return value.strftime("%Y_%m_%dT%H_%M_%S_%f")
def _group_logs_by_host(self, logs):
grouped_logs = defaultdict(list)
for log in logs:
key = getattr(log, self.host_field, 'default_host')
grouped_logs[key].append(log)
return grouped_logs
def _read_grouped_logs(self):
return True
def _read(
self, ti: TaskInstance, try_number: int, metadata: dict | None = None
) -> tuple[EsLogMsgType, dict]:
"""
Endpoint for streaming log.
:param ti: task instance object
:param try_number: try_number of the task instance
:param metadata: log metadata,
can be used for steaming log reading and auto-tailing.
:return: a list of tuple with host and log documents, metadata.
"""
if not metadata:
metadata = {'offset': 0}
if 'offset' not in metadata:
metadata['offset'] = 0
offset = metadata['offset']
log_id = self._render_log_id(ti, try_number)
logs = self.es_read(log_id, offset, metadata)
logs_by_host = self._group_logs_by_host(logs)
next_offset = offset if not logs else attrgetter(self.offset_field)(logs[-1])
# Ensure a string here. Large offset numbers will get JSON.parsed incorrectly
# on the client. Sending as a string prevents this issue.
# https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER
metadata['offset'] = str(next_offset)
# end_of_log_mark may contain characters like '\n' which is needed to
# have the log uploaded but will not be stored in elasticsearch.
metadata['end_of_log'] = False
for logs in logs_by_host.values():
if logs[-1].message == self.end_of_log_mark:
metadata['end_of_log'] = True
cur_ts = pendulum.now()
if 'last_log_timestamp' in metadata:
last_log_ts = timezone.parse(metadata['last_log_timestamp'])
# if we are not getting any logs at all after more than N seconds of trying,
# assume logs do not exist
if int(next_offset) == 0 and cur_ts.diff(last_log_ts).in_seconds() > 5:
metadata['end_of_log'] = True
missing_log_message = (
f"*** Log {log_id} not found in Elasticsearch. "
"If your task started recently, please wait a moment and reload this page. "
"Otherwise, the logs for this task instance may have been removed."
)
return [('', missing_log_message)], metadata
if (
# Assume end of log after not receiving new log for N min,
cur_ts.diff(last_log_ts).in_minutes() >= 5
# if max_offset specified, respect it
or ('max_offset' in metadata and int(offset) >= int(metadata['max_offset']))
):
metadata['end_of_log'] = True
if int(offset) != int(next_offset) or 'last_log_timestamp' not in metadata:
metadata['last_log_timestamp'] = str(cur_ts)
# If we hit the end of the log, remove the actual end_of_log message
# to prevent it from showing in the UI.
def concat_logs(lines):
log_range = (len(lines) - 1) if lines[-1].message == self.end_of_log_mark else len(lines)
return '\n'.join(self._format_msg(lines[i]) for i in range(log_range))
message = [(host, concat_logs(hosted_log)) for host, hosted_log in logs_by_host.items()]
return message, metadata
def _format_msg(self, log_line):
"""Format ES Record to match settings.LOG_FORMAT when used with json_format"""
# Using formatter._style.format makes it future proof i.e.
# if we change the formatter style from '%' to '{' or '$', this will still work
if self.json_format:
try:
return self.formatter._style.format(
logging.makeLogRecord({**LOG_LINE_DEFAULTS, **log_line.to_dict()})
)
except Exception:
pass
# Just a safe-guard to preserve backwards-compatibility
return log_line.message
[docs] def es_read(self, log_id: str, offset: str, metadata: dict) -> list:
"""
Returns the logs matching log_id in Elasticsearch and next offset.
Returns '' if no log is found or there was an error.
:param log_id: the log_id of the log to read.
:param offset: the offset start to read log from.
:param metadata: log metadata, used for steaming log download.
"""
# Offset is the unique key for sorting logs given log_id.
search = Search(using=self.client).query('match_phrase', log_id=log_id).sort(self.offset_field)
search = search.filter('range', **{self.offset_field: {'gt': int(offset)}})
max_log_line = search.count()
if 'download_logs' in metadata and metadata['download_logs'] and 'max_offset' not in metadata:
try:
if max_log_line > 0:
metadata['max_offset'] = attrgetter(self.offset_field)(
search[max_log_line - 1].execute()[-1]
)
else:
metadata['max_offset'] = 0
except Exception:
self.log.exception('Could not get current log size with log_id: %s', log_id)
logs = []
if max_log_line != 0:
try:
logs = search[self.MAX_LINE_PER_PAGE * self.PAGE : self.MAX_LINE_PER_PAGE].execute()
except Exception:
self.log.exception('Could not read log with log_id: %s', log_id)
return logs
[docs] def emit(self, record):
if self.handler:
setattr(record, self.offset_field, int(time() * (10**9)))
self.handler.emit(record)
[docs] def set_context(self, ti: TaskInstance) -> None:
"""
Provide task_instance context to airflow task handler.
:param ti: task instance object
"""
self.mark_end_on_close = not ti.raw
if self.json_format:
self.formatter = ElasticsearchJSONFormatter(
fmt=self.formatter._fmt,
json_fields=self.json_fields + [self.offset_field],
extras={
'dag_id': str(ti.dag_id),
'task_id': str(ti.task_id),
'execution_date': self._clean_date(ti.execution_date),
'try_number': str(ti.try_number),
'log_id': self._render_log_id(ti, ti.try_number),
},
)
if self.write_stdout:
if self.context_set:
# We don't want to re-set up the handler if this logger has
# already been initialized
return
self.handler = logging.StreamHandler(stream=sys.__stdout__)
self.handler.setLevel(self.level)
self.handler.setFormatter(self.formatter)
else:
super().set_context(ti)
self.context_set = True
[docs] def close(self) -> None:
# 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
if not self.mark_end_on_close:
self.closed = True
return
# Case which context of the handler was not set.
if self.handler is None:
self.closed = True
return
# Reopen the file stream, because FileHandler.close() would be called
# first in logging.shutdown() and the stream in it would be set to None.
if self.handler.stream is None or self.handler.stream.closed: # type: ignore[attr-defined]
self.handler.stream = self.handler._open() # type: ignore[union-attr]
# Mark the end of file using end of log mark,
# so we know where to stop while auto-tailing.
self.emit(logging.makeLogRecord({'msg': self.end_of_log_mark}))
if self.write_stdout:
self.handler.close()
sys.stdout = sys.__stdout__
super().close()
self.closed = True
@property
[docs] def log_name(self) -> str:
"""The log name"""
return self.LOG_NAME
[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
"""
log_id = self._render_log_id(task_instance, try_number)
scheme = '' if '://' in self.frontend else 'https://'
return scheme + self.frontend.format(log_id=quote(log_id))
@property
[docs] def supports_external_link(self) -> bool:
"""Whether we can support external links"""
return bool(self.frontend)
