Adding documentation

README.md

@@ -13,6 +13,8 @@ Please note that the documentation is a WIP.
 - Metrics from [Metrics-plugin](https://github.com/jenkinsci/metrics-plugin)
 - Metrics from this plugin. Refer [Prometheus-plugin](docs/metrics/index.md)
 
+## Configuring the plugin
+You can find some examples in this documentation [Configuring Plugin](docs/configuration/configuration.md)
 
 ## Environment variables
 

docs/configuration/configuration.md

@@ -0,0 +1,18 @@
+# Plugin configuration
+
+This page is under construction.
+
+## Disable Metrics (since v2.3.0)
+Sometimes you don't need all metrics in your prometheus endpoint which this plugin provides. 
+You can disable certain metrics. These metrics are not being collected by the plugin and therefore not added in the 
+prometheus endpoint.
+
+![img.png](img/disabled_metrics.png)
+
+### Regex Entry
+A Regex entry can be used to disable a group of metrics. E.g. if you want to disable everything with 
+default_jenkins_disk.*
+
+### Fully qualified Name Entry
+If you want to disable certain individual entries you can do it with this entry. The value should be the same
+as you can see it in the prometheus endpoint. It's case-insensitive. 

src/main/java/org/jenkinsci/plugins/prometheus/config/disabledmetrics/RegexDisabledMetric.java

@@ -34,7 +34,7 @@ public FormValidation doCheckRegex(@QueryParameter String value) {
 
     @Override
     public Descriptor<Entry> getDescriptor() {
-        return new NamedDisabledMetric.DescriptorImpl();
+        return new DescriptorImpl();
     }
 
     @Extension