Add a /metrics endpoint for Prometheus Metrics

yuvipanda · yuvipanda · commit a764f90b142d · 2018-04-02T11:40:25.000-07:00
[Prometheus](https://prometheus.io/) provides a standard metrics format that can be collected and used in many contexts. - From the browser to drive 'current resource usage' displays, such as https://github.com/yuvipanda/nbresuse - From a prometheus server to collect historical data for operational analysis and performance monitoring Example: https://grafana.mybinder.org/dashboard/db/1-overview?refresh=1m&orgId=1 for mybinder.org metrics from JupyterHub and BinderHub, via prometheus server at https://prometheus.mybinder.org The JupyterHub and BinderHub projects already expose Prometheus metrics natively. Adding this to the Jupyter notebook server allows us to instrument the code easily and in a standard format that has lots of 3rd party tooling for it. This commit does the following: - Introduce the `prometheus_client` library as a dependency. This library has no dependencies of its own and is pure python. - Add an authenticated `/metrics` endpoint to the server, which returns metrics in Prometheus Text Format - Expose the default process metrics from `prometheus_client`, which include memory usage and CPU usage info (for just the notebook process)
diff --git a/notebook/base/handlers.py b/notebook/base/handlers.py
@@ -28,6 +28,7 @@
 from jinja2 import TemplateNotFound
 from tornado import web, gen, escape, httputil
 from tornado.log import app_log
+import prometheus_client
 
 from notebook._sysinfo import get_sys_info
 
@@ -809,6 +810,16 @@ def get(self):
         url = sep.join([self._url, self.request.query])
         self.redirect(url, permanent=self._permanent)
 
+class PrometheusMetricsHandler(IPythonHandler):
+    """
+    Return prometheus metrics for this notebook server
+    """
+    @web.authenticated
+    def get(self):
+        self.set_header('Content-Type', prometheus_client.CONTENT_TYPE_LATEST)
+        self.write(prometheus_client.generate_latest(prometheus_client.REGISTRY))
+
+
 #-----------------------------------------------------------------------------
 # URL pattern fragments for re-use
 #-----------------------------------------------------------------------------
@@ -825,4 +836,5 @@ def get(self):
     (r".*/", TrailingSlashHandler),
     (r"api", APIVersionHandler),
     (r'/(robots\.txt|favicon\.ico)', web.StaticFileHandler),
+    (r'/metrics', PrometheusMetricsHandler)
 ]
diff --git a/setup.py b/setup.py
@@ -87,7 +87,8 @@
         'nbconvert',
         'ipykernel', # bless IPython kernel for now
         'Send2Trash',
-        'terminado>=0.8.1'
+        'terminado>=0.8.1',
+        'prometheus_client'
     ],
     extras_require = {
         'test:python_version == "2.7"': ['mock'],
