-
Notifications
You must be signed in to change notification settings - Fork 250
/
middleware.py
304 lines (242 loc) · 10.4 KB
/
middleware.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
# Copyright 2017, OpenCensus Authors
#
# Licensed 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.
"""Django middleware helper to capture and trace a request."""
import six
import logging
import sys
import traceback
import django
import django.conf
from django.db import connection
from django.utils.deprecation import MiddlewareMixin
from google.rpc import code_pb2
from opencensus.common import configuration
from opencensus.trace import (
attributes_helper,
execution_context,
integrations,
print_exporter,
samplers,
)
from opencensus.trace import span as span_module
from opencensus.trace import status as status_module
from opencensus.trace import tracer as tracer_module
from opencensus.trace import utils
from opencensus.trace.propagation import trace_context_http_header_format
HTTP_HOST = attributes_helper.COMMON_ATTRIBUTES['HTTP_HOST']
HTTP_METHOD = attributes_helper.COMMON_ATTRIBUTES['HTTP_METHOD']
HTTP_PATH = attributes_helper.COMMON_ATTRIBUTES['HTTP_PATH']
HTTP_ROUTE = attributes_helper.COMMON_ATTRIBUTES['HTTP_ROUTE']
HTTP_URL = attributes_helper.COMMON_ATTRIBUTES['HTTP_URL']
HTTP_STATUS_CODE = attributes_helper.COMMON_ATTRIBUTES['HTTP_STATUS_CODE']
ERROR_MESSAGE = attributes_helper.COMMON_ATTRIBUTES['ERROR_MESSAGE']
ERROR_NAME = attributes_helper.COMMON_ATTRIBUTES['ERROR_NAME']
STACKTRACE = attributes_helper.COMMON_ATTRIBUTES['STACKTRACE']
REQUEST_THREAD_LOCAL_KEY = 'django_request'
SPAN_THREAD_LOCAL_KEY = 'django_span'
EXCLUDELIST_PATHS = 'EXCLUDELIST_PATHS'
EXCLUDELIST_HOSTNAMES = 'EXCLUDELIST_HOSTNAMES'
log = logging.getLogger(__name__)
class _DjangoMetaWrapper(object):
"""
Wrapper class which takes HTTP header name and retrieve the value from
Django request.META
"""
def __init__(self, meta=None):
self.meta = meta or _get_django_request().META
def get(self, key):
return self.meta.get('HTTP_' + key.upper().replace('-', '_'))
def _get_django_request():
"""Get Django request from thread local.
:rtype: str
:returns: Django request.
"""
return execution_context.get_opencensus_attr(REQUEST_THREAD_LOCAL_KEY)
def _get_django_span():
"""Get Django span from thread local.
:rtype: str
:returns: Django request.
"""
return execution_context.get_opencensus_attr(SPAN_THREAD_LOCAL_KEY)
def _get_current_tracer():
"""Get the current request tracer."""
return execution_context.get_opencensus_tracer()
def _set_django_attributes(span, request):
"""Set the django related attributes."""
django_user = getattr(request, 'user', None)
if django_user is None:
return
user_id = django_user.pk
user_name = django_user.get_username()
# User id is the django autofield for User model as the primary key
if user_id is not None:
span.add_attribute('django.user.id', str(user_id))
if user_name is not None:
span.add_attribute('django.user.name', str(user_name))
def _trace_db_call(execute, sql, params, many, context):
tracer = _get_current_tracer()
if not tracer:
return execute(sql, params, many, context)
vendor = context['connection'].vendor
alias = context['connection'].alias
span = tracer.start_span()
span.name = '{}.query'.format(vendor)
span.span_kind = span_module.SpanKind.CLIENT
tracer.add_attribute_to_current_span('component', vendor)
tracer.add_attribute_to_current_span('db.instance', alias)
tracer.add_attribute_to_current_span('db.statement', sql)
tracer.add_attribute_to_current_span('db.type', 'sql')
try:
result = execute(sql, params, many, context)
except Exception: # pragma: NO COVER
status = status_module.Status(
code=code_pb2.UNKNOWN, message='DB error'
)
span.set_status(status)
raise
else:
return result
finally:
tracer.end_span()
class OpencensusMiddleware(MiddlewareMixin):
"""Saves the request in thread local"""
def __init__(self, get_response):
super(OpencensusMiddleware, self).__init__(get_response)
settings = getattr(django.conf.settings, 'OPENCENSUS', {})
settings = settings.get('TRACE', {})
self.sampler = (settings.get('SAMPLER', None)
or samplers.ProbabilitySampler())
if isinstance(self.sampler, six.string_types):
self.sampler = configuration.load(self.sampler)
self.exporter = settings.get('EXPORTER', None) or \
print_exporter.PrintExporter()
if isinstance(self.exporter, six.string_types):
self.exporter = configuration.load(self.exporter)
self.propagator = settings.get('PROPAGATOR', None) or \
trace_context_http_header_format.TraceContextPropagator()
if isinstance(self.propagator, six.string_types):
self.propagator = configuration.load(self.propagator)
self.excludelist_paths = settings.get(EXCLUDELIST_PATHS, None)
self.excludelist_hostnames = settings.get(EXCLUDELIST_HOSTNAMES, None)
if django.VERSION >= (2,): # pragma: NO COVER
connection.execute_wrappers.append(_trace_db_call)
# pylint: disable=protected-access
integrations.add_integration(integrations._Integrations.DJANGO)
def process_request(self, request):
"""Called on each request, before Django decides which view to execute.
:type request: :class:`~django.http.request.HttpRequest`
:param request: Django http request.
"""
# Do not trace if the url is excludelisted
if utils.disable_tracing_url(request.path, self.excludelist_paths):
return
# Add the request to thread local
execution_context.set_opencensus_attr(
REQUEST_THREAD_LOCAL_KEY,
request)
execution_context.set_opencensus_attr(
'excludelist_hostnames',
self.excludelist_hostnames)
try:
# Start tracing this request
span_context = self.propagator.from_headers(
_DjangoMetaWrapper(_get_django_request().META))
# Reload the tracer with the new span context
tracer = tracer_module.Tracer(
span_context=span_context,
sampler=self.sampler,
exporter=self.exporter,
propagator=self.propagator)
# Span name is being set at process_view
span = tracer.start_span()
span.span_kind = span_module.SpanKind.SERVER
tracer.add_attribute_to_current_span(
attribute_key=HTTP_HOST,
attribute_value=request.get_host())
tracer.add_attribute_to_current_span(
attribute_key=HTTP_METHOD,
attribute_value=request.method)
tracer.add_attribute_to_current_span(
attribute_key=HTTP_PATH,
attribute_value=str(request.path))
tracer.add_attribute_to_current_span(
attribute_key=HTTP_ROUTE,
attribute_value=str(request.path))
tracer.add_attribute_to_current_span(
attribute_key=HTTP_URL,
attribute_value=str(request.build_absolute_uri()))
# Add the span to thread local
# in some cases (exceptions, timeouts) currentspan in
# response event will be one of a child spans.
# let's keep reference to 'django' span and
# use it in response event
execution_context.set_opencensus_attr(
SPAN_THREAD_LOCAL_KEY,
span)
except Exception: # pragma: NO COVER
log.error('Failed to trace request', exc_info=True)
def process_view(self, request, view_func, *args, **kwargs):
"""Process view is executed before the view function, here we get the
function name add set it as the span name.
"""
# Do not trace if the url is excludelisted
if utils.disable_tracing_url(request.path, self.excludelist_paths):
return
try:
# Get the current span and set the span name to the current
# function name of the request.
tracer = _get_current_tracer()
span = tracer.current_span()
span.name = utils.get_func_name(view_func)
except Exception: # pragma: NO COVER
log.error('Failed to trace request', exc_info=True)
def process_response(self, request, response):
# Do not trace if the url is excludelisted
if utils.disable_tracing_url(request.path, self.excludelist_paths):
return response
try:
span = _get_django_span()
span.add_attribute(
attribute_key=HTTP_STATUS_CODE,
attribute_value=response.status_code)
_set_django_attributes(span, request)
tracer = _get_current_tracer()
tracer.end_span()
tracer.finish()
except Exception: # pragma: NO COVER
log.error('Failed to trace request', exc_info=True)
finally:
return response
def process_exception(self, request, exception):
# Do not trace if the url is excluded
if utils.disable_tracing_url(request.path, self.excludelist_paths):
return
try:
if hasattr(exception, '__traceback__'):
tb = exception.__traceback__
else:
_, _, tb = sys.exc_info()
span = _get_django_span()
span.add_attribute(
attribute_key=ERROR_NAME,
attribute_value=exception.__class__.__name__)
span.add_attribute(
attribute_key=ERROR_MESSAGE,
attribute_value=str(exception))
span.add_attribute(
attribute_key=STACKTRACE,
attribute_value='\n'.join(traceback.format_tb(tb)))
_set_django_attributes(span, request)
except Exception: # pragma: NO COVER
log.error('Failed to trace request', exc_info=True)