/
es_task_handler.py
361 lines (303 loc) · 14 KB
/
es_task_handler.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
#
# 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.
import logging
import sys
from collections import defaultdict
from datetime import datetime
from operator import attrgetter
from time import time
from typing import List, Optional, 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 import TaskInstance
from airflow.utils import timezone
from airflow.utils.helpers import parse_template_string
from airflow.utils.log.file_task_handler import FileTaskHandler
from airflow.utils.log.json_formatter import JSONFormatter
from airflow.utils.log.logging_mixin import LoggingMixin
# Elasticsearch hosted log type
EsLogMsgType = List[Tuple[str, str]]
class ElasticsearchTaskHandler(FileTaskHandler, LoggingMixin):
"""
ElasticsearchTaskHandler is a python log handler that
reads logs from Elasticsearch. Note logs are not directly
indexed into Elasticsearch. Instead, it flushes logs
into local files. Additional software setup is required
to index the log into Elasticsearch, such as using
Filebeat and Logstash.
To efficiently query and sort Elasticsearch results, we assume 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.
Timestamp here are unreliable because multiple log messages
might have the same timestamp.
"""
PAGE = 0
MAX_LINE_PER_PAGE = 1000
LOG_NAME = 'Elasticsearch'
def __init__( # pylint: disable=too-many-arguments
self,
base_log_folder: str,
filename_template: str,
log_id_template: 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: Optional[dict] = conf.getsection("elasticsearch_configs"),
):
"""
: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.log_id_template, self.log_id_jinja_template = parse_template_string(log_id_template)
self.client = elasticsearch.Elasticsearch([host], **es_kwargs)
self.frontend = frontend
self.mark_end_on_close = True
self.end_of_log_mark = end_of_log_mark
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.handler = None
self.context_set = False
def _render_log_id(self, ti: TaskInstance, try_number: int) -> str:
if self.log_id_jinja_template:
jinja_context = ti.get_template_context()
jinja_context['try_number'] = try_number
return self.log_id_jinja_template.render(**jinja_context)
if self.json_format:
execution_date = self._clean_execution_date(ti.execution_date)
else:
execution_date = ti.execution_date.isoformat()
return self.log_id_template.format(
dag_id=ti.dag_id, task_id=ti.task_id, execution_date=execution_date, try_number=try_number
)
@staticmethod
def _clean_execution_date(execution_date: datetime) -> str:
"""
Clean up an execution date 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
:param execution_date: execution date of the dag run.
"""
return execution_date.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 items sorted by timestamp.
result = sorted(grouped_logs.items(), key=lambda kv: getattr(kv[1][0], 'message', '_'))
return result
def _read_grouped_logs(self):
return True
def _read(
self, ti: TaskInstance, try_number: int, metadata: Optional[dict] = 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.
loading_hosts = [
item[0] for item in logs_by_host if item[-1][-1].message != self.end_of_log_mark.strip()
]
metadata['end_of_log'] = False if not logs else len(loading_hosts) == 0
cur_ts = pendulum.now()
# Assume end of log after not receiving new log for 5 min,
# as executor heartbeat is 1 min and there might be some
# delay before Elasticsearch makes the log available.
if 'last_log_timestamp' in metadata:
last_log_ts = timezone.parse(metadata['last_log_timestamp'])
if (
cur_ts.diff(last_log_ts).in_minutes() >= 5
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.strip() 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]
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:
# pylint: disable=protected-access
return self.formatter._style.format(_ESJsonLogFmt(self.json_fields, **log_line.to_dict()))
except Exception: # noqa pylint: disable=broad-except
pass
# Just a safe-guard to preserve backwards-compatibility
return log_line.message
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.
:type log_id: str
:param offset: the offset start to read log from.
:type offset: str
:param metadata: log metadata, used for steaming log download.
:type metadata: dict
"""
# 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: # pylint: disable=broad-except
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: # pylint: disable=broad-except
self.log.exception('Could not read log with log_id: %s', log_id)
return logs
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 = JSONFormatter(
fmt=self.formatter._fmt, # pylint: disable=protected-access
json_fields=self.json_fields,
extras={
'dag_id': str(ti.dag_id),
'task_id': str(ti.task_id),
'execution_date': self._clean_execution_date(ti.execution_date),
'try_number': str(ti.try_number),
'log_id': self._render_log_id(ti, ti.try_number),
'offset': int(time() * (10 ** 9)),
},
)
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__) # type: ignore
self.handler.setLevel(self.level) # type: ignore
self.handler.setFormatter(self.formatter) # type: ignore
else:
super().set_context(ti)
self.context_set = True
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:
self.handler.stream = self.handler._open() # pylint: disable=protected-access
# Mark the end of file using end of log mark,
# so we know where to stop while auto-tailing.
self.handler.stream.write(self.end_of_log_mark)
if self.write_stdout:
self.handler.close()
sys.stdout = sys.__stdout__
super().close()
self.closed = True
@property
def log_name(self) -> str:
"""The log name"""
return self.LOG_NAME
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
:type: task_instance: TaskInstance
:param try_number: task instance try_number to read logs from.
:type try_number: Optional[int]
:return: URL to the external log collection service
:rtype: str
"""
log_id = self.log_id_template.format(
dag_id=task_instance.dag_id,
task_id=task_instance.task_id,
execution_date=task_instance.execution_date,
try_number=try_number,
)
url = 'https://' + self.frontend.format(log_id=quote(log_id))
return url
class _ESJsonLogFmt:
"""Helper class to read ES Logs and re-format it to match settings.LOG_FORMAT"""
# A separate class is needed because 'self.formatter._style.format' uses '.__dict__'
def __init__(self, json_fields: List, **kwargs):
for field in json_fields:
self.__setattr__(field, '')
self.__dict__.update(kwargs)