Merge pull request #2857 from jimmidyson/prometheus-datasource

Prometheus fixes

docs/sources/datasources/prometheus.md

@@ -8,7 +8,7 @@ page_keywords: grafana, prometheus, metrics, query, documentation
 Grafana includes support for Prometheus Datasources. While the process of adding the datasource is similar to adding a Graphite or OpenTSDB datasource type, Prometheus does have a few different options for building queries.
 
 ## Adding the data source to Grafana
-![](/img/v2/add_Prometheus.jpg)
+![](/img/v2/add_Prometheus.png)
 
 1. Open the side menu by clicking the the Grafana icon in the top header. 
 2. In the side menu under the `Dashboards` link you should find a link named `Data Sources`.    

docs/sources/index.md

@@ -10,7 +10,7 @@ It provides a powerful and elegant way to create, share, and explore data and da
 
 Grafana is most commonly used for Internet infrastructure and application analytics, but many use it in other domains including industrial sensors, home automation, weather, and process control.
 
-Grafana features pluggable panels and data sources allowing easy extensibility. There is currently rich support for [Graphite](http://graphite.readthedocs.org/en/latest/), [InfluxDB](http://influxdb.org) and [OpenTSDB](http://opentsdb.net). There is also experimental support for [KairosDB](https://github.com/kairosdb/kairosdb), and SQL is on the roadmap. Grafana has a variety of panels, including a fully featured graph panel with rich visualization options.
+Grafana features pluggable panels and data sources allowing easy extensibility. There is currently rich support for [Graphite](http://graphite.readthedocs.org/en/latest/), [InfluxDB](http://influxdb.org) and [OpenTSDB](http://opentsdb.net). There is also experimental support for [KairosDB](https://github.com/kairosdb/kairosdb), [Prometheus](http://prometheus.io/), and SQL is on the roadmap. Grafana has a variety of panels, including a fully featured graph panel with rich visualization options.
 
 Version 2.0 was released in April 2015: Grafana now ships with its own backend server that brings [many changes and features](../guides/whats-new-in-v2/).    
 Version 2.1 was released in July 2015 and added [even more features and enhancements](../guides/whats-new-in-v2-1/).

public/app/plugins/datasource/prometheus/datasource.js

@@ -212,7 +212,7 @@ function (angular, _, moment, dateMath) {
     };
 
     PrometheusDatasource.prototype.testDatasource = function() {
-      return this.metricFindQuery('*').then(function() {
+      return this.metricFindQuery('metrics(.*)').then(function() {
         return { status: 'success', message: 'Data source is working', title: 'Success' };
       });
     };