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+# NodeGopher
+is a Node Graph Grafana/Prometheus helper
+
+Its purpose in life is to help you create NodeGraphs like network or application topology, arranging nodes and edges, and dynamically query prometheus to add stat to graph items.  
+
+It support instant and range queries. Range query results will be averaged to get one metric.  
+
+Technically, it is an API which builds json nodegraph structure to be exposed to grafana. To enrich this structure with metrics, nodegopher query a prometheus instance.  
+It gets time range values from Grafana, so it can relay them to prometheus if you want to average values from a time range.  
+
+## Configuration
+see config.yaml.sample  
+
+## Grafana datasource
+Successfully tested with yesoreyeram-infinity-datasource datasource  
+
+Create an infinity query, name it "Edges". Type "JSON", Parser "Backend", Source "URL", Format "Table", Method "GET"  
+URL: "http://my-nodegopher-host:8080/graph1/edges?from=$__from&to=$__to&interval=$__interval"  
+
+Create a second infinity query named "Nodes", same config,  
+URL: "http://my-nodegopher-host:8080/graph1/nodes?from=$__from&to=$__to&interval=$__interval"  
+
+switch to visualization type "NodeGraph", and voila
+
+## Instance management
+### Reload configuration
+You can reload configuration file when the API is running, with either sending a signal, or make a POST request.  
+
+Using SIGHUP :
+```
+kill -HUP `pgrep nodegopher`
+```
+
+Sending POST on /reload :
+```
+curl -XPOST http://my-nodegopher-host:8080/reload
+{"message":"configuration successfully reloaded"}
+```