T973: reorganizes basic strucutre

-adds documentation for prometheus exporter

docs/configuration/service/monitoring.rst

@@ -53,6 +53,8 @@ Telegraf output plugin azure-data-explorer_
 Prometheus client
 =================
 Telegraf output plugin prometheus-client_
+This plugin allows export of Telegraf metrics to Prometheus,
+for Prometheus native metrics through node-exporter see section below.
 
 .. cfgcmd:: set service monitoring telegraf prometheus-client
 
@@ -192,3 +194,49 @@ Telegraf can be used to send logs to Loki using tags as labels.
 .. _azure-data-explorer: https://github.com/influxdata/telegraf/tree/master/plugins/outputs/azure_data_explorer
 .. _prometheus-client: https://github.com/influxdata/telegraf/tree/master/plugins/outputs/prometheus_client
 .. _splunk: https://www.splunk.com/en_us/blog/it/splunk-metrics-via-telegraf.html
+
+
+**********
+Prometheus
+**********
+
+The following Prometheus exporters are configurable to export metrics:
+ * Node Exporter
+ * FRR Exporter
+
+
+Node Exporter
+=============
+Prometheus node_exporter_ which provides a wide range of hardware and OS metrics.
+
+.. cfgcmd:: set service monitoring node-exporter listen-address <address>
+
+  Configure the address node_exporter is listening on.
+
+.. cfgcmd:: set service monitoring node-exporter port <port>
+
+  Configure the port number node_exporter is listening on.
+
+.. cfgcmd:: set service monitoring node-exporter vrf <name>
+
+  Configure name of the :abbr:`VRF (Virtual Routing and Forwarding)` instance.
+
+
+FRR Exporter
+============
+Prometheus frr_exporter_ which provides free range routing metrics.
+
+.. cfgcmd:: set service monitoring frr-exporter listen-address <address>
+
+  Configure the address frr_exporter is listening on.
+
+.. cfgcmd:: set service monitoring frr-exporter port <port>
+
+  Configure the port number frr_exporter is listening on.
+
+.. cfgcmd:: set service monitoring frr-exporter vrf <name>
+
+  Configure name of the :abbr:`VRF (Virtual Routing and Forwarding)` instance.
+
+.. _node_exporter: https://github.com/prometheus/node_exporter
+.. _frr_exporter: https://github.com/tynany/frr_exporter