Multiprocess environment variable in upper case

README.md

@@ -502,7 +502,7 @@ There's several steps to getting this working:
 
 **1. Gunicorn deployment**:
 
-The `prometheus_multiproc_dir` environment variable must be set to a directory
+The `PROMETHEUS_MULTIPROC_DIR` environment variable must be set to a directory
 that the client library can use for metrics. This directory must be wiped
 between Gunicorn runs (before startup is recommended).
 

prometheus_client/multiprocess.py

@@ -66,7 +66,7 @@ def _parse_key(key):
                     # the file is missing
                     continue
                 raise
-            for key, value, pos in file_values:
+            for key, value, _ in file_values:
                 metric_name, name, labels, labels_key = _parse_key(key)
 
                 metric = metrics.get(metric_name)

prometheus_client/values.py

@@ -2,6 +2,7 @@
 
 import os
 from threading import Lock
+import warnings
 
 from .mmap_dict import mmap_key, MmapedDict
 
@@ -64,7 +65,7 @@ def __reset(self):
                 file_prefix = typ
             if file_prefix not in files:
                 filename = os.path.join(
-                    os.environ['prometheus_multiproc_dir'],
+                    os.environ.get('PROMETHEUS_MULTIPROC_DIR'),
                     '{0}_{1}.db'.format(file_prefix, pid['value']))
 
                 files[file_prefix] = MmapedDict(filename)
@@ -108,7 +109,10 @@ def get_value_class():
     # This needs to be chosen before the first metric is constructed,
     # and as that may be in some arbitrary library the user/admin has
     # no control over we use an environment variable.
-    if 'prometheus_multiproc_dir' in os.environ:
+    if 'prometheus_multiproc_dir' in os.environ and 'PROMETHEUS_MULTIPROC_DIR' not in os.environ:
+        os.environ['PROMETHEUS_MULTIPROC_DIR'] = os.environ['prometheus_multiproc_dir']
+        warnings.warn("You should declare the env variable in upper case PROMETHEUS_MULTIPROC_DIR'", DeprecationWarning)
+    if 'PROMETHEUS_MULTIPROC_DIR' in os.environ:
         return MultiProcessValue()
     else:
         return MutexValue

tests/test_multiprocess.py

@@ -5,6 +5,7 @@
 import shutil
 import sys
 import tempfile
+import warnings
 
 from prometheus_client import mmap_dict, values
 from prometheus_client.core import (
@@ -13,7 +14,9 @@
 from prometheus_client.multiprocess import (
     mark_process_dead, MultiProcessCollector,
 )
-from prometheus_client.values import MultiProcessValue, MutexValue
+from prometheus_client.values import (
+    get_value_class, MultiProcessValue, MutexValue,
+)
 
 if sys.version_info < (2, 7):
     # We need the skip decorators from unittest2 on Python 2.6.
@@ -22,10 +25,36 @@
     import unittest
 
 
-class TestMultiProcess(unittest.TestCase):
+class TestMultiProcessDeprecation(unittest.TestCase):
     def setUp(self):
         self.tempdir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        del os.environ['prometheus_multiproc_dir']
+        del os.environ['PROMETHEUS_MULTIPROC_DIR']
+        shutil.rmtree(self.tempdir)
+
+    def test_deprecation_warning(self):
         os.environ['prometheus_multiproc_dir'] = self.tempdir
+        with warnings.catch_warnings(record=True) as w:
+            get_value_class()
+            assert os.environ['PROMETHEUS_MULTIPROC_DIR'] == self.tempdir
+            assert len(w) == 1
+            assert issubclass(w[-1].category, DeprecationWarning)
+            assert "PROMETHEUS_MULTIPROC_DIR" in str(w[-1].message)
+
+    def test_both_variables_priority(self):
+        os.environ['prometheus_multiproc_dir'] = 'should not be picked'
+        os.environ['PROMETHEUS_MULTIPROC_DIR'] = self.tempdir
+        with warnings.catch_warnings(record=True) as w:
+            get_value_class()
+            assert len(w) == 0
+
+
+class TestMultiProcess(unittest.TestCase):
+    def setUp(self):
+        self.tempdir = tempfile.mkdtemp()
+        os.environ['PROMETHEUS_MULTIPROC_DIR'] = self.tempdir
         values.ValueClass = MultiProcessValue(lambda: 123)
         self.registry = CollectorRegistry()
         self.collector = MultiProcessCollector(self.registry, self.tempdir)
@@ -35,7 +64,7 @@ def _value_class(self):
         return
 
     def tearDown(self):
-        del os.environ['prometheus_multiproc_dir']
+        del os.environ['PROMETHEUS_MULTIPROC_DIR']
         shutil.rmtree(self.tempdir)
         values.ValueClass = MutexValue
 
@@ -80,7 +109,7 @@ def test_gauge_all(self):
         self.assertEqual(0, self.registry.get_sample_value('g', {'pid': '456'}))
         g1.set(1)
         g2.set(2)
-        mark_process_dead(123, os.environ['prometheus_multiproc_dir'])
+        mark_process_dead(123, os.environ['PROMETHEUS_MULTIPROC_DIR'])
         self.assertEqual(1, self.registry.get_sample_value('g', {'pid': '123'}))
         self.assertEqual(2, self.registry.get_sample_value('g', {'pid': '456'}))
 
@@ -94,7 +123,7 @@ def test_gauge_liveall(self):
         g2.set(2)
         self.assertEqual(1, self.registry.get_sample_value('g', {'pid': '123'}))
         self.assertEqual(2, self.registry.get_sample_value('g', {'pid': '456'}))
-        mark_process_dead(123, os.environ['prometheus_multiproc_dir'])
+        mark_process_dead(123, os.environ['PROMETHEUS_MULTIPROC_DIR'])
         self.assertEqual(None, self.registry.get_sample_value('g', {'pid': '123'}))
         self.assertEqual(2, self.registry.get_sample_value('g', {'pid': '456'}))
 
@@ -124,7 +153,7 @@ def test_gauge_livesum(self):
         g1.set(1)
         g2.set(2)
         self.assertEqual(3, self.registry.get_sample_value('g'))
-        mark_process_dead(123, os.environ['prometheus_multiproc_dir'])
+        mark_process_dead(123, os.environ['PROMETHEUS_MULTIPROC_DIR'])
         self.assertEqual(2, self.registry.get_sample_value('g'))
 
     def test_namespace_subsystem(self):
@@ -151,7 +180,7 @@ def test_initialization_detects_pid_change(self):
         # can not inspect the files cache directly, as it's a closure, so we
         # check for the actual files themselves
         def files():
-            fs = os.listdir(os.environ['prometheus_multiproc_dir'])
+            fs = os.listdir(os.environ['PROMETHEUS_MULTIPROC_DIR'])
             fs.sort()
             return fs
 
@@ -240,7 +269,7 @@ def add_label(key, value):
         pid = 1
         h.labels(**labels).observe(5)
 
-        path = os.path.join(os.environ['prometheus_multiproc_dir'], '*.db')
+        path = os.path.join(os.environ['PROMETHEUS_MULTIPROC_DIR'], '*.db')
         files = glob.glob(path)
         metrics = dict(
             (m.name, m) for m in self.collector.merge(files, accumulate=False)