nstat plugin cleanups and formatting

closes #1104
closes #1138

README.md

@@ -186,6 +186,7 @@ Currently implemented sources:
 * [net_response](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/net_response)
 * [nginx](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/nginx)
 * [nsq](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/nsq)
+* [nstat](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/nstat)
 * [ntpq](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/ntpq)
 * [phpfpm](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/phpfpm)
 * [phusion passenger](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/passenger)

etc/telegraf.conf

@@ -940,6 +940,18 @@
 #   endpoints = ["http://localhost:4151"]
 
 
+# # Collect kernel snmp counters and network interface statistics
+# [[inputs.nstat]]
+#   ## file paths for proc files. If empty default paths will be used:
+#   ##    /proc/net/netstat, /proc/net/snmp, /proc/net/snmp6
+#   ## These can also be overridden with env variables, see README.
+#   proc_net_netstat = ""
+#   proc_net_snmp    = ""
+#   proc_net_snmp6   = ""
+#   ## dump metrics with 0 values too
+#   dump_zeros       = true
+
+
 # # Get standard NTP query metrics, requires ntpq executable.
 # [[inputs.ntpq]]
 #   ## If false, set the -n ntpq flag. Can reduce metric gather time.

plugins/inputs/nstat/README.md

@@ -1,27 +1,28 @@
 ## Nstat input plugin
 
-Plugin collects network metrics from ```/proc/net/netstat```, ```/proc/net/snmp``` and ```/proc/net/snmp6``` files
+Plugin collects network metrics from `/proc/net/netstat`, `/proc/net/snmp` and `/proc/net/snmp6` files
 
 ### Configuration
+
 The plugin firstly tries to read file paths from config values
 if it is empty, then it reads from env variables.
-* ```PROC_NET_NETSTAT```
-* ```PROC_NET_SNMP```
-* ```PROC_NET_SNMP6```
+* `PROC_NET_NETSTAT`
+* `PROC_NET_SNMP`
+* `PROC_NET_SNMP6`
 
 If these variables are also not set,
-then it tries to read the proc root from env - ```PROC_ROOT```,
-and sets ```/proc``` as a root path if ```PROC_ROOT``` is also empty.
+then it tries to read the proc root from env - `PROC_ROOT`,
+and sets `/proc` as a root path if `PROC_ROOT` is also empty.
 
 Then appends default file paths:
-* ```/net/netstat```
-* ```/net/snmp```
-* ```/net/snmp6```
+* `/net/netstat`
+* `/net/snmp`
+* `/net/snmp6`
 
 So if nothing is given, no paths in config and in env vars, the plugin takes the default paths.
-* ```/proc/net/netstat```
-* ```/proc/net/snmp```
-* ```/proc/net/snmp6```
+* `/proc/net/netstat`
+* `/proc/net/snmp`
+* `/proc/net/snmp6`
 
 The sample config file
 ```toml

plugins/inputs/nstat/nstat.go

@@ -40,17 +40,18 @@ type Nstat struct {
 }
 
 var sampleConfig = `
-  # file paths
-  # e.g: /proc/net/netstat, /proc/net/snmp, /proc/net/snmp6
+  ## file paths for proc files. If empty default paths will be used:
+  ##    /proc/net/netstat, /proc/net/snmp, /proc/net/snmp6
+  ## These can also be overridden with env variables, see README.
   proc_net_netstat = ""
   proc_net_snmp    = ""
   proc_net_snmp6   = ""
-  # dump metrics with 0 values too
+  ## dump metrics with 0 values too
   dump_zeros       = true
 `
 
 func (ns *Nstat) Description() string {
-	return "Collect network metrics from '/proc/net/netstat', '/proc/net/snmp' & '/proc/net/snmp6' files"
+	return "Collect kernel snmp counters and network interface statistics"
 }
 
 func (ns *Nstat) SampleConfig() string {