Introduce exclude_user_defaults to apply excluded_paths to user-defin…

…ed default metrics

Fixes 108

README.md

@@ -24,7 +24,7 @@ or paste it into requirements.txt:
 prometheus-flask-exporter
 
 # or with specific version number
-prometheus-flask-exporter==0.18.2
+prometheus-flask-exporter==0.18.3
 ```
 and then install dependencies from requirements.txt file as usual:
 ```
@@ -150,10 +150,11 @@ You can avoid recording metrics on individual endpoints
 by decorating them with `@metrics.do_not_track()`, or use the 
 `excluded_paths` argument when creating the `PrometheusMetrics` instance
 that takes a regular expression (either a single string, or a list) and
-matching paths will be excluded. If you have functions that are inherited
-or otherwise get metrics collected that you don't want, you can use
-`@metrics.exclude_all_metrics()` to exclude both default and non-default
-metrics being collected from it.
+matching paths will be excluded. These apply to both built-in and user-defined
+default metrics, unless you disable it by setting the `exclude_user_defaults`
+argument to `False`. If you have functions that are inherited or otherwise get
+metrics collected that you don't want, you can use `@metrics.exclude_all_metrics()`
+to exclude both default and non-default metrics being collected from it.
 
 ## Configuration
 

prometheus_flask_exporter/__init__.py

@@ -1,18 +1,18 @@
+import functools
+import inspect
 import os
 import re
 import sys
-import inspect
-import warnings
-import functools
 import threading
+import warnings
 from timeit import default_timer
 
-from flask import request, make_response, current_app
 from flask import Flask, Response
+from flask import request, make_response, current_app
 from flask.views import MethodViewType
-from werkzeug.serving import is_running_from_reloader
 from prometheus_client import Counter, Histogram, Gauge, Summary
 from prometheus_client.exposition import choose_encoder
+from werkzeug.serving import is_running_from_reloader
 
 if sys.version_info[0:2] >= (3, 4):
     # Python v3.4+ has a built-in has __wrapped__ attribute
@@ -102,12 +102,18 @@ def echo_status(status):
         - Without an argument, possibly to use with the Flask `request` object
     """
 
-    def __init__(self, app, path='/metrics',
-                 export_defaults=True, defaults_prefix='flask',
-                 group_by='path', buckets=None,
+    def __init__(self, app,
+                 path='/metrics',
+                 export_defaults=True,
+                 defaults_prefix='flask',
+                 group_by='path',
+                 buckets=None,
                  default_latency_as_histogram=True,
-                 default_labels=None, response_converter=None,
-                 excluded_paths=None, metrics_decorator=None,
+                 default_labels=None,
+                 response_converter=None,
+                 excluded_paths=None,
+                 exclude_user_defaults=True,
+                 metrics_decorator=None,
                  registry=None, **kwargs):
         """
         Create a new Prometheus metrics export configuration.
@@ -135,6 +141,8 @@ def __init__(self, app, path='/metrics',
             metrics endpoint, takes a function and needs to return a function
         :param excluded_paths: regular expression(s) as a string or
             a list of strings for paths to exclude from tracking
+        :param exclude_user_defaults: also apply the `excluded_paths`
+            exclusions to user-defined defaults (not only built-in ones)
         :param registry: the Prometheus Registry to use
         """
 
@@ -194,6 +202,8 @@ def __init__(self, app, path='/metrics',
         else:
             self.excluded_paths = None
 
+        self.exclude_user_defaults = exclude_user_defaults
+
         if app is not None:
             self.init_app(app)
 
@@ -623,6 +633,11 @@ def get_metric(response):
         def decorator(f):
             @wraps(f)
             def func(*args, **kwargs):
+                if self.exclude_user_defaults and self.excluded_paths:
+                    # exclude based on default excludes
+                    if any(pattern.match(request.path) for pattern in self.excluded_paths):
+                        return f(*args, **kwargs)
+
                 if before:
                     metric = get_metric(None)
                     before(metric)
@@ -915,4 +930,4 @@ def _make_response(response):
         return _make_response
 
 
-__version__ = '0.18.2'
+__version__ = '0.18.3'

setup.py

@@ -6,15 +6,15 @@
 setup(
     name='prometheus_flask_exporter',
     packages=['prometheus_flask_exporter'],
-    version='0.18.2',
+    version='0.18.3',
     description='Prometheus metrics exporter for Flask',
     long_description=long_description,
     long_description_content_type='text/markdown',
     license='MIT',
     author='Viktor Adam',
     author_email='rycus86@gmail.com',
     url='https://github.com/rycus86/prometheus_flask_exporter',
-    download_url='https://github.com/rycus86/prometheus_flask_exporter/archive/0.18.2.tar.gz',
+    download_url='https://github.com/rycus86/prometheus_flask_exporter/archive/0.18.3.tar.gz',
     keywords=['prometheus', 'flask', 'monitoring', 'exporter'],
     classifiers=[
         'Development Status :: 4 - Beta',

tests/test_endpoint.py

@@ -406,3 +406,40 @@ def excluded_two():
             'flask_http_request_duration_seconds_count',
             ('method', 'GET'), ('status', 200), ('path', '/exc/two')
         )
+
+    def test_exclude_paths_from_user_metrics(self):
+        metrics = self.metrics(excluded_paths='/excluded', exclude_user_defaults=True)
+
+        @self.app.route('/included')
+        def included():
+            return 'OK'
+
+        @self.app.route('/excluded')
+        def excluded():
+            return 'OK'
+
+        metrics.register_default(
+            metrics.counter(
+                name='by_path_counter',
+                description='Request count by path',
+                labels={'path': lambda: request.path}
+            )
+        )
+
+        for _ in range(5):
+            self.client.get('/included')
+            self.client.get('/excluded')
+
+        self.assertMetric(
+            'flask_http_request_total', 5.0,
+            ('method', 'GET'), ('status', 200)
+        )
+
+        self.assertMetric(
+            'by_path_counter_total', 5.0,
+            ('path', '/included')
+        )
+        self.assertAbsent(
+            'by_path_counter_total',
+            ('path', '/excluded')
+        )