Working test python gunicorn+prom script.

.gitignore

+*.pyc
+/metrics

myapp.py

+import pprint
+
+def app(environ, start_response):
+        data = b"Hello, World!\n"
+        start_response("200 OK", [
+            ("Content-Type", "text/plain"),
+            ("Content-Length", str(len(data)))
+        ])
+        pprint.pprint(environ)
+        return iter([data])

promapp.py

+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+#
+# Copyright © 2017 kevin <kevin@phrye.com>
+#
+# Distributed under terms of the GPL license.
+
+"""
+Prometheus multi-proc test app.
+"""
+
+import os
+from prometheus_client import multiprocess
+from prometheus_client import generate_latest, CollectorRegistry, CONTENT_TYPE_LATEST, Gauge
+
+# Example gauge.
+IN_PROGRESS = Gauge("inprogress_requests", "help", multiprocess_mode='livesum')
+INDEX = Gauge("index_hits", "help", multiprocess_mode='livesum')
+INDEX_PRO = Gauge("index_pro_hits", "help", ['pro'], multiprocess_mode='livesum')
+REG = CollectorRegistry()
+multiprocess.MultiProcessCollector(REG)
+
+
+def index(environ, start_response):
+  INDEX.inc()
+  INDEX_PRO.labels(str(os.getpid())).inc()
+  data = b"Hello, World!\n"
+  start_response("200 OK", [
+    ("Content-Type", "text/plain"),
+    ("Content-Length", str(len(data)))
+    ])
+  return iter([data])
+
+def metrics(environ, start_response):
+  data = generate_latest(REG)
+  status = '200 OK'
+  response_headers = [
+    ('Content-type', CONTENT_TYPE_LATEST),
+    ('Content-Length', str(len(data)))
+  ]
+  start_response(status, response_headers)
+  return iter([data])
+
+# Expose metrics.
+@IN_PROGRESS.track_inprogress()
+def app(environ, start_response):
+  path = environ.get('PATH_INFO', '')
+  if path == '/metrics':
+    return metrics(environ, start_response)
+  else:
+    return index(environ, start_response)

run.sh

+#! /bin/sh
+
+prometheus_multiproc_dir=metrics/ gunicorn -w 4 promapp:app