Applying PR feedback

- Linked to varnish in input README
- Updated README/CHANGELOG
- Cleaned up sampleConfig to remove formatting
- Shorted lines to 80 chars (except where test input requires long strings)
- Using internal.RunTimeout to wrap call to varnishtat
- Added dummy file for windows

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ### Features
 
+- [#1173](https://github.com/influxdata/telegraf/pull/1173): varnish input plugin. Thanks @sfox-xmatters!
 - [#1138](https://github.com/influxdata/telegraf/pull/1138): nstat input plugin. Thanks @Maksadbek!
 - [#1139](https://github.com/influxdata/telegraf/pull/1139): instrumental output plugin. Thanks @jasonroelofs!
 - [#1172](https://github.com/influxdata/telegraf/pull/1172): Ceph storage stats. Thanks @robinpercy!

README.md

@@ -207,6 +207,7 @@ Currently implemented sources:
 * [snmp](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/snmp)
 * [sql server](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/sqlserver) (microsoft)
 * [twemproxy](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/twemproxy)
+* [varnish](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/varnish)
 * [zfs](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/zfs)
 * [zookeeper](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/zookeeper)
 * [win_perf_counters ](https://github.com/influxdata/telegraf/tree/master/plugins/inputs/win_perf_counters) (windows performance counters)

plugins/inputs/varnish/README.md

@@ -1,19 +1,19 @@
 # Varnish Input Plugin
 
-This plugin gathers stats from Varnish HTTP Cache
+This plugin gathers stats from [Varnish HTTP Cache](https://varnish-cache.org/)
 
 ### Configuration:
 
 ```toml
-# # A plugin to collect stats from Varnish HTTP Cache
-# [[inputs.varnish]]
-#   ## The default location of the varnishstat binary can be overridden with:
-#   binary = "/usr/bin/varnishstat"
-#
-#   ## By default, telegraf gather stats for 3 metric points.
-#   ## Setting stats will override the defaults (["MAIN.cache_hit","MAIN.cache_miss","MAIN.uptime"]).
-#   ## stats may also be set to ["all"], which will collect all stats
-#   stats = ["MAIN.cache_hit","MAIN.cache_miss","MAIN.uptime"]
+ # A plugin to collect stats from Varnish HTTP Cache
+ [[inputs.varnish]]
+   ## The default location of the varnishstat binary can be overridden with:
+   binary = "/usr/bin/varnishstat"
+
+   ## By default, telegraf gathers stats for 3 metric points.
+   ## Setting stats will override the defaults shown below.
+   ## stats may also be set to ["all"], which will collect all stats
+   stats = ["MAIN.cache_hit", "MAIN.cache_miss", "MAIN.uptime"]
 ```
 
 ### Measurements & Fields:

plugins/inputs/varnish/varnish.go

@@ -1,6 +1,6 @@
-package varnish
+// +build !windows
 
-// varnish.go
+package varnish
 
 import (
 	"bufio"
@@ -13,6 +13,8 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
+	"github.com/influxdata/telegraf/internal"
+	"time"
 )
 
 const (
@@ -33,9 +35,9 @@ var varnishSampleConfig = `
   binary = "/usr/bin/varnishstat"
 
   ## By default, telegraf gather stats for 3 metric points.
-  ## Setting stats will override the defaults (["%s"]).
+  ## Setting stats will override the defaults shown below.
   ## stats may also be set to ["all"], which will collect all stats
-  stats = ["%[1]s"]
+  stats = ["MAIN.cache_hit", "MAIN.cache_miss", "MAIN.uptime"]
 `
 
 func (s *Varnish) Description() string {
@@ -87,7 +89,7 @@ var varnishStat = func(cmdName string) (*bytes.Buffer, error) {
 	cmd := exec.Command(cmdName, cmdArgs...)
 	var out bytes.Buffer
 	cmd.Stdout = &out
-	err := cmd.Run()
+	err := internal.RunTimeout(cmd, time.Millisecond*200)
 	if err != nil {
 		return &out, fmt.Errorf("error running varnishstat: %s", err)
 	}

plugins/inputs/varnish/varnish_test.go

@@ -1,3 +1,5 @@
+// +build !windows
+
 package varnish
 
 import (
@@ -119,11 +121,11 @@ var smOutput = `
 MAIN.uptime                895         1.00 Child process uptime
 MAIN.cache_hit                     95         0.00 Cache hits
 MAIN.cache_miss                    5          0.00 Cache misses
-MGT.uptime                                 896         1.00 Management process uptime
-MGT.child_start                              1         0.00 Child process started
-MEMPOOL.vbc.live                             0          .   In use
-MEMPOOL.vbc.pool                            10          .   In Pool
-MEMPOOL.vbc.sz_wanted                       88          .   Size requested
+MGT.uptime                         896         1.00 Management process uptime
+MGT.child_start                    1         0.00 Child process started
+MEMPOOL.vbc.live                   0          .   In use
+MEMPOOL.vbc.pool                   10          .   In Pool
+MEMPOOL.vbc.sz_wanted              88          .   Size requested
 `
 
 var parsedSmOutput = map[string]map[string]interface{}{

plugins/inputs/varnish/varnish_windows.go

@@ -0,0 +1,3 @@
+// +build windows
+
+package varnish