title: Prometheus json metrics
body: <p>The application I want to monitor provides an api endpoint for health checks that responds with metrics in json. As an example:</p>
  
  <pre><code>$ curl  https://example.com/api/stats
  {"status":"success","code":0,"data":{"UserCount":140,"UserCountActive":23}}
  </code></pre>
  
  <p>I have setup the Prometheus blackbox_exporter to monitor that this endpoint returns <code>200 Ok</code> however I'd ideally like to get those metrics too. I understand instrumentation exports this data directly from the application. But since the application is already exporting what I want in a json object, I would prefer the convenience of not maintaining my own fork of this software to include the Prometheus libraries necessary for instrumentation.  How should I consume metrics that are in json?</p>