Merge pull request #98 from qbiqing/master

Update env var to `PROMETHEUS_MULTIPROC_DIR`

README.md

@@ -352,7 +352,7 @@ This should return `True` on one process only, and the underlying
 [Prometheus client library](https://github.com/prometheus/client_python)
 will collect the metrics for all the forked children or siblings.
 
-__Note:__ this needs the `prometheus_multiproc_dir` environment variable
+__Note:__ this needs the `PROMETHEUS_MULTIPROC_DIR` environment variable
 to point to a valid, writable directory.
 
 You'll also have to call the `metrics.start_http_server()` function

examples/gunicorn-app-factory/Dockerfile

@@ -12,6 +12,7 @@ ADD examples/gunicorn-app-factory/server.py \
     /var/flask/
 WORKDIR /var/flask
 
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
 ENV prometheus_multiproc_dir /tmp
 
 CMD gunicorn -c config.py -w 4 -b 0.0.0.0:4000 server:app

examples/gunicorn-internal/Dockerfile

@@ -9,6 +9,7 @@ RUN pip install -e /tmp/latest --upgrade
 ADD examples/gunicorn-internal/server.py examples/gunicorn-internal/config.py /var/flask/
 WORKDIR /var/flask
 
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
 ENV prometheus_multiproc_dir /tmp
 
 CMD gunicorn -c config.py -w 4 -b 0.0.0.0:4000 server:app

examples/gunicorn/Dockerfile

@@ -9,6 +9,7 @@ RUN pip install -e /tmp/latest --upgrade
 ADD examples/gunicorn/server.py examples/gunicorn/config.py /var/flask/
 WORKDIR /var/flask
 
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
 ENV prometheus_multiproc_dir /tmp
 ENV METRICS_PORT 9200
 

examples/pytest-app-factory/Dockerfile

@@ -5,7 +5,8 @@ RUN pip install flask pytest
 ADD . /tmp/latest
 RUN pip install -e /tmp/latest --upgrade
 
-ENV prometheus_multiproc_dir=/tmp
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
+ENV prometheus_multiproc_dir /tmp
 ENV PYTHONPATH=/data
 
 ADD ./examples/pytest-app-factory /data

examples/uwsgi-connexion/Dockerfile

@@ -10,7 +10,8 @@ RUN pip install -e /tmp/latest --upgrade
 ADD examples/uwsgi-connexion /var/flask
 WORKDIR /var/flask
 
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
 ENV prometheus_multiproc_dir /tmp
 ENV METRICS_PORT 9200
 
-CMD uwsgi --http 0.0.0.0:4000 --module main:app --master --processes 4 --threads 2
+CMD uwsgi --http 0.0.0.0:4000 --module main:app --master --processes 4 --threads 2

examples/uwsgi-lazy-apps/Dockerfile

@@ -11,6 +11,7 @@ RUN pip install -e /tmp/latest --upgrade
 ADD examples/uwsgi-lazy-apps/server.py /var/flask/
 WORKDIR /var/flask
 
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
 ENV prometheus_multiproc_dir /tmp
 
 CMD uwsgi --http 0.0.0.0:4000 --module server:app --master --processes 4 --threads 2 --lazy-apps

examples/uwsgi/Dockerfile

@@ -11,6 +11,7 @@ RUN pip install -e /tmp/latest --upgrade
 ADD examples/uwsgi/server.py /var/flask/
 WORKDIR /var/flask
 
+ENV PROMETHEUS_MULTIPROC_DIR /tmp
 ENV prometheus_multiproc_dir /tmp
 ENV METRICS_PORT 9200
 

examples/wsgi/wsgi.py

@@ -3,6 +3,7 @@
 
 sys.path.insert(0, os.path.dirname(__file__))
 
+os.environ["PROMETHEUS_MULTIPROC_DIR"] = "/tmp"
 os.environ["prometheus_multiproc_dir"] = "/tmp"
 
-from app import app as application
+from app import app as application

prometheus_flask_exporter/__init__.py

@@ -257,15 +257,15 @@ def prometheus_metrics():
             # import these here so they don't clash with our own multiprocess module
             from prometheus_client import multiprocess, CollectorRegistry
 
-            if 'prometheus_multiproc_dir' in os.environ:
+            if 'PROMETHEUS_MULTIPROC_DIR' in os.environ or 'prometheus_multiproc_dir' in os.environ:
                 registry = CollectorRegistry()
             else:
                 registry = self.registry
 
             if 'name[]' in request.args:
                 registry = registry.restricted_registry(request.args.getlist('name[]'))
 
-            if 'prometheus_multiproc_dir' in os.environ:
+            if 'PROMETHEUS_MULTIPROC_DIR' in os.environ or 'prometheus_multiproc_dir' in os.environ:
                 multiprocess.MultiProcessCollector(registry)
 
             generate_latest, content_type = choose_encoder(request.headers.get("Accept"))

prometheus_flask_exporter/multiprocess.py

@@ -11,18 +11,22 @@
 
 def _check_multiproc_env_var():
     """
-    Checks that the `prometheus_multiproc_dir` environment variable is set,
+    Checks that the `PROMETHEUS_MULTIPROC_DIR` environment variable is set,
     which is required for the multiprocess collector to work properly.
 
     :raises ValueError: if the environment variable is not set
         or if it does not point to a directory
     """
 
-    if 'prometheus_multiproc_dir' in os.environ:
+    if 'PROMETHEUS_MULTIPROC_DIR' in os.environ:
+        if os.path.isdir(os.environ['PROMETHEUS_MULTIPROC_DIR']):
+            return
+    elif 'prometheus_multiproc_dir' in os.environ:
         if os.path.isdir(os.environ['prometheus_multiproc_dir']):
             return
 
-    raise ValueError('env prometheus_multiproc_dir is not set or not a directory')
+    raise ValueError('one of env PROMETHEUS_MULTIPROC_DIR or env prometheus_multiproc_dir' +
+        'must be set and be a directory')
 
 
 class MultiprocessPrometheusMetrics(PrometheusMetrics):

tests/test_extensions.py

@@ -18,7 +18,10 @@ class ExtensionsTest(BaseTestCase):
     def setUp(self):
         super(ExtensionsTest, self).setUp()
 
-        if 'prometheus_multiproc_dir' not in os.environ:
+        if 'PROMETHEUS_MULTIPROC_DIR' not in os.environ:
+            os.environ['PROMETHEUS_MULTIPROC_DIR'] = '/tmp'
+            self._multiproc_dir_added = True
+        elif 'prometheus_multiproc_dir' not in os.environ:
             os.environ['prometheus_multiproc_dir'] = '/tmp'
             self._multiproc_dir_added = True
         else:
@@ -41,7 +44,10 @@ def setUp(self):
 
     def tearDown(self):
         if self._multiproc_dir_added:
-            del os.environ['prometheus_multiproc_dir']
+            if os.environ.get('PROMETHEUS_MULTIPROC_DIR'):
+                del os.environ['PROMETHEUS_MULTIPROC_DIR']
+            if os.environ.get('prometheus_multiproc_dir'):
+                del os.environ['prometheus_multiproc_dir']
 
     def test_with_defaults(self):
         for extension_type in self._all_extensions:
@@ -114,3 +120,41 @@ def test_with_other_parameters(self):
                 else:
                     self.assertIs(getattr(obj, arg), value,
                                   'Unexpected %s object in %s' % (arg, extension_type.__name__))
+
+    def test_prometheus_multiproc_env_var_change(self):
+        for extension_type in self._all_extensions:
+            if extension_type in [
+                MultiprocessPrometheusMetrics, UWsgiPrometheusMetrics,
+                GunicornPrometheusMetrics, GunicornInternalPrometheusMetrics
+            ]:
+                # Check only lower case env var works
+                if os.environ.get('PROMETHEUS_MULTIPROC_DIR'):
+                    del os.environ['PROMETHEUS_MULTIPROC_DIR']
+                os.environ['prometheus_multiproc_dir'] = '/tmp'
+
+                try:
+                    app = Flask(__name__)
+                    app.testing = True
+                    flask_app = app
+
+                    obj = extension_type(app=app)
+                except Exception as ex:
+                    self.fail('Failed to instantiate %s: %s' % (extension_type.__name__, ex))
+
+                self.assertIs(obj.app, flask_app, 'Unexpected app object in %s' % extension_type.__name__)
+
+                # Check only upper case env var works
+                if os.environ.get('prometheus_multiproc_dir'):
+                    del os.environ['prometheus_multiproc_dir']
+                os.environ['PROMETHEUS_MULTIPROC_DIR'] = '/tmp'
+
+                try:
+                    app2 = Flask(__name__)
+                    app2.testing = True
+                    flask_app2 = app2
+
+                    obj2 = extension_type(app=app2)
+                except Exception as ex:
+                    self.fail('Failed to instantiate %s: %s' % (extension_type.__name__, ex))
+
+                self.assertIs(obj2.app, flask_app2, 'Unexpected app object in %s' % extension_type.__name__)