From 2cf5685519c6f18bafdf2fe829752e12d26f6090 Mon Sep 17 00:00:00 2001
From: Cameron Sparr <cameronsparr@gmail.com>
Date: Wed, 9 Mar 2016 17:22:34 +0100
Subject: [PATCH] Add number of users to 'system' plugin

see #235
---
 CHANGELOG.md                           |  1 +
 plugins/inputs/system/SYSTEM_README.md | 35 ++++++++++++++++++++++++++
 plugins/inputs/system/system.go        |  6 +++++
 3 files changed, 42 insertions(+)
 create mode 100644 plugins/inputs/system/SYSTEM_README.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5ef68bd45..28ce825c5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
 - [#799](https://github.com/influxdata/telegraf/pull/799): Add number of threads for procstat input plugin. Thanks @titilambert!
 - [#776](https://github.com/influxdata/telegraf/pull/776): Add Zookeeper chroot option to kafka_consumer. Thanks @prune998!
 - [#811](https://github.com/influxdata/telegraf/pull/811): Add processes plugin for classifying total procs on system. Thanks @titilambert!
+- [#235](https://github.com/influxdata/telegraf/issues/235): Add number of users to the `system` input plugin.
 
 ### Bugfixes
 - [#748](https://github.com/influxdata/telegraf/issues/748): Fix sensor plugin split on ":"
diff --git a/plugins/inputs/system/SYSTEM_README.md b/plugins/inputs/system/SYSTEM_README.md
new file mode 100644
index 000000000..fc873c7e8
--- /dev/null
+++ b/plugins/inputs/system/SYSTEM_README.md
@@ -0,0 +1,35 @@
+# System Input Plugin
+
+The system plugin gathers general stats on system load, uptime,
+and number of users logged in. It is basically equivalent
+to the unix `uptime` command.
+
+### Configuration:
+
+```toml
+# Read metrics about system load & uptime
+[[inputs.system]]
+  # no configuration
+```
+
+### Measurements & Fields:
+
+- system
+    - load1 (float)
+    - load15 (float)
+    - load5 (float)
+    - n_users (integer)
+    - uptime (integer, seconds)
+    - uptime_format (string)
+
+### Tags:
+
+None
+
+### Example Output:
+
+```
+$ telegraf -config ~/ws/telegraf.conf -input-filter system -test
+* Plugin: system, Collection 1
+> system load1=2.05,load15=2.38,load5=2.03,n_users=4i,uptime=239043i,uptime_format="2 days, 18:24" 1457546165399253452
+```
diff --git a/plugins/inputs/system/system.go b/plugins/inputs/system/system.go
index 9922d5a92..42b0310a4 100644
--- a/plugins/inputs/system/system.go
+++ b/plugins/inputs/system/system.go
@@ -31,11 +31,17 @@ func (_ *SystemStats) Gather(acc telegraf.Accumulator) error {
 		return err
 	}
 
+	users, err := host.Users()
+	if err != nil {
+		return err
+	}
+
 	fields := map[string]interface{}{
 		"load1":         loadavg.Load1,
 		"load5":         loadavg.Load5,
 		"load15":        loadavg.Load15,
 		"uptime":        hostinfo.Uptime,
+		"n_users":       len(users),
 		"uptime_format": format_uptime(hostinfo.Uptime),
 	}
 	acc.AddFields("system", fields, nil)