Add system uptime metricset

This adds a new metricset that reports the system uptime. The metricset
is enabled by default with a period of 15m.

The metricset reports one field `system.uptime.duration.ms` that is the system's
uptime reported in milliseconds. In Kibana the field is formatted as a `duration`
and shown in human-readable format (e.g. "8 days").

Closes elastic#4848

CHANGELOG.asciidoc

@@ -83,6 +83,8 @@ https://github.com/elastic/beats/compare/v6.0.0-beta1...master[Check the HEAD di
 - Add http server metricset to support push metrics via http. {pull}4770[4770]
 - Make config object public for graphite and http server {pull}4820[4820]
 
+- Add system uptime metricset. {issue}[4848[4848]
+
 *Packetbeat*
 
 *Winlogbeat*

libbeat/scripts/generate_index_pattern.py

@@ -79,6 +79,11 @@ def field_to_json(fields, desc, path, output,
         if "format" in desc:
             fieldFormat["id"] = desc["format"]
 
+            if "input_format" in desc:
+                fieldFormat["params"] = {
+                    "inputFormat": desc["input_format"]
+                }
+
         if "pattern" in desc:
             fieldFormat["params"] = {
                 "pattern": desc["pattern"]

metricbeat/docs/fields.asciidoc

@@ -10144,6 +10144,23 @@ type: keyword
 Name of the user running the process.
 
 
+[float]
+== uptime fields
+
+`uptime` contains the operating system uptime metric.
+
+
+
+[float]
+=== `system.uptime.duration.ms`
+
+type: long
+
+format: duration
+
+The OS uptime in milliseconds.
+
+
 [[exported-fields-vsphere]]
 == vSphere fields
 

metricbeat/docs/modules/system.asciidoc

@@ -109,6 +109,10 @@ metricbeat.modules:
   processors:
   - drop_event.when.regexp:
       system.filesystem.mount_point: '^/(sys|cgroup|proc|dev|etc|host|lib)($|/)'
+
+- module: system
+  period: 15m
+  metricsets: [uptime]
 ----
 
 [float]
@@ -138,6 +142,8 @@ The following metricsets are available:
 
 * <<metricbeat-metricset-system-socket,socket>>
 
+* <<metricbeat-metricset-system-uptime,uptime>>
+
 include::system/core.asciidoc[]
 
 include::system/cpu.asciidoc[]
@@ -160,3 +166,5 @@ include::system/process_summary.asciidoc[]
 
 include::system/socket.asciidoc[]
 
+include::system/uptime.asciidoc[]
+

metricbeat/docs/modules/system/uptime.asciidoc

@@ -0,0 +1,19 @@
+////
+This file is generated! See scripts/docs_collector.py
+////
+
+[[metricbeat-metricset-system-uptime]]
+include::../../../module/system/uptime/_meta/docs.asciidoc[]
+
+
+==== Fields
+
+For a description of each field in the metricset, see the
+<<exported-fields-system,exported fields>> section.
+
+Here is an example document generated by this metricset:
+
+[source,json]
+----
+include::../../../module/system/uptime/_meta/data.json[]
+----

metricbeat/include/list.go

@@ -101,6 +101,7 @@ import (
 	_ "github.com/elastic/beats/metricbeat/module/system/process"
 	_ "github.com/elastic/beats/metricbeat/module/system/process_summary"
 	_ "github.com/elastic/beats/metricbeat/module/system/socket"
+	_ "github.com/elastic/beats/metricbeat/module/system/uptime"
 	_ "github.com/elastic/beats/metricbeat/module/vsphere"
 	_ "github.com/elastic/beats/metricbeat/module/vsphere/datastore"
 	_ "github.com/elastic/beats/metricbeat/module/vsphere/host"

metricbeat/metricbeat.reference.yml

@@ -40,6 +40,7 @@ metricbeat.modules:
     - network         # Network IO
     - process         # Per process metrics
     - process_summary # Process summary
+    - uptime          # System Uptime
     #- core           # Per CPU core usage
     #- diskio         # Disk IO
     #- socket         # Sockets and connection info (linux only)

metricbeat/module/system/_meta/config.reference.yml

@@ -8,6 +8,7 @@
     - network         # Network IO
     - process         # Per process metrics
     - process_summary # Process summary
+    - uptime          # System Uptime
     #- core           # Per CPU core usage
     #- diskio         # Disk IO
     #- socket         # Sockets and connection info (linux only)

metricbeat/module/system/_meta/config.yml

@@ -23,3 +23,7 @@
   processors:
   - drop_event.when.regexp:
       system.filesystem.mount_point: '^/(sys|cgroup|proc|dev|etc|host|lib)($|/)'
+
+- module: system
+  period: 15m
+  metricsets: [uptime]

metricbeat/module/system/uptime/_meta/data.json

@@ -0,0 +1,23 @@
+{
+  "@timestamp": "2016-05-23T08:05:34.853Z",
+  "@metadata": {
+    "beat": "noindex",
+    "type": "doc"
+  },
+  "system": {
+    "uptime": {
+      "duration": {
+        "ms": 695499821
+      }
+    }
+  },
+  "metricset": {
+    "module": "system",
+    "name": "uptime",
+    "rtt": 115
+  },
+  "beat": {
+    "name": "host.example.com",
+    "hostname": "host.example.com"
+  }
+}

metricbeat/module/system/uptime/_meta/docs.asciidoc

@@ -0,0 +1,10 @@
+=== System Uptime Metricset
+
+The System `uptime` metricset provides the uptime of the host operating system.
+
+This metricset is available on:
+
+- Darwin
+- Linux
+- OpenBSD
+- Windows

metricbeat/module/system/uptime/_meta/fields.yml

@@ -0,0 +1,11 @@
+- name: uptime
+  type: group
+  description: >
+    `uptime` contains the operating system uptime metric.
+  fields:
+    - name: duration.ms
+      type: long
+      format: duration
+      input_format: milliseconds
+      description: >
+        The OS uptime in milliseconds.

metricbeat/module/system/uptime/doc.go

@@ -0,0 +1,2 @@
+// Package uptime reports the system's uptime.
+package uptime

metricbeat/module/system/uptime/metricset.go

@@ -0,0 +1,42 @@
+// +build darwin linux openbsd windows
+
+package uptime
+
+import (
+	"github.com/pkg/errors"
+
+	"github.com/elastic/beats/libbeat/common"
+	"github.com/elastic/beats/metricbeat/mb"
+	"github.com/elastic/beats/metricbeat/mb/parse"
+	sigar "github.com/elastic/gosigar"
+)
+
+func init() {
+	if err := mb.Registry.AddMetricSet("system", "uptime", New, parse.EmptyHostParser); err != nil {
+		panic(err)
+	}
+}
+
+// MetricSet for fetching an OS uptime metric.
+type MetricSet struct {
+	mb.BaseMetricSet
+}
+
+// New is a mb.MetricSetFactory that returns a new MetricSet.
+func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
+	return &MetricSet{base}, nil
+}
+
+// Fetch fetches the uptime metric from the OS.
+func (m *MetricSet) Fetch() (common.MapStr, error) {
+	var uptime sigar.Uptime
+	if err := uptime.Get(); err != nil {
+		return nil, errors.Wrap(err, "failed to get uptime")
+	}
+
+	return common.MapStr{
+		"duration": common.MapStr{
+			"ms": int64(uptime.Length * 1000),
+		},
+	}, nil
+}

metricbeat/module/system/uptime/metricset_test.go

@@ -0,0 +1,28 @@
+// +build darwin linux openbsd windows
+
+package uptime
+
+import (
+	"testing"
+
+	mbtest "github.com/elastic/beats/metricbeat/mb/testing"
+)
+
+func TestData(t *testing.T) {
+	f := mbtest.NewEventFetcher(t, getConfig())
+
+	uptime, err := f.Fetch()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	event := mbtest.CreateFullEvent(f, uptime)
+	mbtest.WriteEventToDataJSON(t, event)
+}
+
+func getConfig() map[string]interface{} {
+	return map[string]interface{}{
+		"module":     "system",
+		"metricsets": []string{"uptime"},
+	}
+}

metricbeat/modules.d/system.yml

@@ -23,3 +23,7 @@
   processors:
   - drop_event.when.regexp:
       system.filesystem.mount_point: '^/(sys|cgroup|proc|dev|etc|host|lib)($|/)'
+
+- module: system
+  period: 15m
+  metricsets: [uptime]