Implement a direct to prometheus export for c2cwsgiutils_stats_db

Redirect warnings to logging

.dockerignore

@@ -6,3 +6,4 @@
 !rel_requirements.txt
 !setup.py
 !setup.cfg
+!tests

Dockerfile

@@ -9,7 +9,8 @@ RUN pip install --no-cache-dir -r /c2cwsgiutils/rel_requirements.txt
 
 COPY . /c2cwsgiutils/
 RUN flake8 /c2cwsgiutils && \
-    pip install --no-cache-dir -e /c2cwsgiutils
+    pip install --no-cache-dir -e /c2cwsgiutils && \
+    (cd /c2cwsgiutils/ && pytest -vv tests && rm -r tests)
 
 ENV LOG_TYPE=console \
     LOG_HOST=localhost \

acceptance_tests/app/test_app.iml

@@ -4,7 +4,6 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/c2cwsgiutils_app" isTestSource="false" />
-      <excludeFolder url="file://$MODULE_DIR$/c2cwsgiutils" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />

acceptance_tests/tests/acceptance.iml

@@ -4,7 +4,6 @@
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/tests" isTestSource="false" />
-      <excludeFolder url="file://$MODULE_DIR$/c2cwsgiutils" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />

c2cwsgiutils/prometheus.py

@@ -0,0 +1,38 @@
+"""
+Implement parts of the Prometheus Pushgateway protocol, as defined here:
+https://github.com/prometheus/pushgateway
+"""
+import requests
+
+
+class PushgatewayGroupPublisher(object):
+    def __init__(self, base_url, job, instance=None):
+        if not base_url.endswith('/'):
+            base_url += '/'
+        self._url = "%smetrics/job/%s" % (base_url, job)
+        if instance is not None:
+            self._url += '/instance/' + instance
+        self._reset()
+
+    def add(self, metric_name, metric_value, metric_type='gauge', metric_labels=None):
+        if metric_name in self._types:
+            if self._types[metric_name] != metric_type:
+                raise ValueError("Cannot change the type of a given metric")
+        else:
+            self._types[metric_name] = metric_type
+            self._to_send += '# TYPE %s %s\n' % (metric_name, metric_type)
+        self._to_send += metric_name
+        if metric_labels is not None:
+            self._to_send += '{' + ', '.join('%s="%s"' % (k, v) for k, v in metric_labels.items()) + '}'
+        self._to_send += ' %s\n' % metric_value
+
+    def commit(self):
+        requests.put(self._url, data=self._to_send).raise_for_status()
+        self._reset()
+
+    def _reset(self):
+        self._to_send = ''
+        self._types = {}
+
+    def __str__(self):
+        return self._url + ' ->\n' + self._to_send

c2cwsgiutils/wsgi.py

@@ -12,6 +12,7 @@ def create_application(configfile=None):
     :param config: The configuration file to use
     :return: The application
     """
+    logging.captureWarnings(True)
     if configfile is None:
         configfile = os.environ.get('C2CWSGIUTILS_CONFIG', "/app/production.ini")
     # Load the logging config without using pyramid to be able to use environment variables in there.

c2cwsgiutils_stats_db.py

@@ -12,6 +12,7 @@
 from zope.sqlalchemy import ZopeTransactionExtension
 
 from c2cwsgiutils import stats
+from c2cwsgiutils.prometheus import PushgatewayGroupPublisher
 
 logging.basicConfig(level=logging.INFO,
                     format="%(asctime)-15s %(levelname)5s %(name)s %(message)s",
@@ -28,6 +29,9 @@ def _parse_args():
                         help='A SQL query that returns a metric name and a value')
     parser.add_argument('--statsd_address', type=str, help='address:port for the statsd daemon')
     parser.add_argument('--statsd_prefix', type=str, default='c2c', help='prefix for the statsd metrics')
+    parser.add_argument('--prometheus_url', type=str, help='Base URL for the Prometheus Pushgateway')
+    parser.add_argument('--prometheus_instance', type=str,
+                        help='Instance name for the Prometheus Pushgateway')
     parser.add_argument('--verbosity', type=str, default='INFO')
     args = parser.parse_args()
     logging.root.setLevel(args.verbosity)
@@ -41,12 +45,28 @@ def __init__(self, args):
         else:
             self.statsd = None
 
+        if args.prometheus_url:
+            self.prometheus = PushgatewayGroupPublisher(args.prometheus_url, 'db_counts',
+                                                        instance=args.prometheus_instance)
+        else:
+            self.prometheus = None
+
     def do_report(self, metric, count):
         LOG.info("%s -> %d", ".".join(metric), count)
         if self.statsd is not None:
             self.statsd.gauge(metric, count)
+        if self.prometheus is not None:
+
+            self.prometheus.add('database_table_count', count, metric_labels={
+                'metric': ".".join(v.replace('.', '_') for v in metric)
+            })
+
+    def commit(self):
+        if self.prometheus is not None:
+            self.prometheus.commit()
+
 
-    def error(self, metric):
+def error(self, metric):
         if self.statsd is not None:
             self.statsd.counter(['error'] + metric, 1)
 
@@ -83,16 +103,15 @@ def main():
             do_table(session, schema, table, reporter)
         except Exception:
             reporter.error([schema, table])
-            raise
 
     if args.extra:
         for pos, extra in enumerate(args.extra):
             try:
                 do_extra(session, extra, reporter)
             except Exception:
                 reporter.error(['extra', str(pos + 1)])
-                raise
 
+    reporter.commit()
     transaction.abort()
 
 

setup.py

@@ -2,7 +2,7 @@
 from setuptools import setup, find_packages
 
 
-VERSION = '0.16.1'
+VERSION = '0.16.2'
 HERE = os.path.abspath(os.path.dirname(__file__))
 INSTALL_REQUIRES = open(os.path.join(HERE, 'rel_requirements.txt')).read().splitlines()
 

tests/test_prometheus.py

@@ -0,0 +1,19 @@
+import pytest
+
+from c2cwsgiutils.prometheus import PushgatewayGroupPublisher
+
+
+def test_pushgateway_group_publisher():
+    publisher = PushgatewayGroupPublisher('http://example.com/', 'test')
+    publisher.add('metric1', 12)
+    publisher.add('metric2', 13, metric_labels={'toto': 'TOTO', 'tutu': 'TUTU'})
+    publisher.add('metric2', 14, metric_labels={'toto': 'TOTO', 'tutu': 'TITI'})
+    with pytest.raises(ValueError):
+        publisher.add('metric1', 12, metric_type='counter')
+
+    assert str(publisher) == 'http://example.com/metrics/job/test ->\n' \
+                             '# TYPE metric1 gauge\n' \
+                             'metric1 12\n' \
+                             '# TYPE metric2 gauge\n' \
+                             'metric2{toto="TOTO", tutu="TUTU"} 13\n' \
+                             'metric2{toto="TOTO", tutu="TITI"} 14\n'