From e35a9f6b86a65631caa058eafec969ee93d525f2 Mon Sep 17 00:00:00 2001
From: Thomas Roehl <Thomas.Roehl@googlemail.com>
Date: Wed, 12 May 2021 16:57:18 +0200
Subject: [PATCH] Add Cpustat collector for /proc/stat

---
 collectors/cpustatMetric.go | 70 +++++++++++++++++++++++++++++++++++++
 config.json                 |  3 +-
 metric-collector.go         |  1 +
 3 files changed, 73 insertions(+), 1 deletion(-)
 create mode 100644 collectors/cpustatMetric.go

diff --git a/collectors/cpustatMetric.go b/collectors/cpustatMetric.go
new file mode 100644
index 0000000..ea498d9
--- /dev/null
+++ b/collectors/cpustatMetric.go
@@ -0,0 +1,70 @@
+package collectors
+
+import (
+	"io/ioutil"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const CPUSTATFILE = `/proc/stat`
+
+type CpustatCollector struct {
+	MetricCollector
+}
+
+func (m *CpustatCollector) Init() {
+	m.name = "CpustatCollector"
+	m.setup()
+}
+
+func ParseStatLine(line string, out map[string]interface{}) {
+    ls := strings.Fields(line)
+    user, _ := strconv.ParseInt(ls[1], 0, 64)
+    out["cpu_user"] = float64(user)
+    nice, _ := strconv.ParseInt(ls[2], 0, 64)
+    out["cpu_nice"] = float64(nice)
+    system, _ := strconv.ParseInt(ls[3], 0, 64)
+    out["cpu_system"] = float64(system)
+    idle, _ := strconv.ParseInt(ls[4], 0, 64)
+    out["cpu_idle"] = float64(idle)
+    iowait, _ := strconv.ParseInt(ls[5], 0, 64)
+    out["cpu_iowait"] = float64(iowait)
+    irq, _ := strconv.ParseInt(ls[6], 0, 64)
+    out["cpu_irq"] = float64(irq)
+    softirq, _ := strconv.ParseInt(ls[7], 0, 64)
+    out["cpu_softirq"] = float64(softirq)
+    steal, _ := strconv.ParseInt(ls[8], 0, 64)
+    out["cpu_steal"] = float64(steal)
+    guest, _ := strconv.ParseInt(ls[9], 0, 64)
+    out["cpu_guest"] = float64(guest)
+    guest_nice, _ := strconv.ParseInt(ls[10], 0, 64)
+    out["cpu_guest_nice"] = float64(guest_nice)
+}
+
+func (m *CpustatCollector) Read(interval time.Duration) {
+	buffer, err := ioutil.ReadFile(string(CPUSTATFILE))
+
+	if err != nil {
+		return
+	}
+
+    ll := strings.Split(string(buffer), "\n")
+    for _, line := range ll {
+        if (len(line) == 0) {
+            continue
+        }
+        ls := strings.Fields(line)
+        if (strings.Compare(ls[0], "cpu") == 0) {
+            ParseStatLine(line, m.node)
+        } else if (strings.HasPrefix(ls[0], "cpu")) {
+            cpustr := strings.TrimLeft(ls[0], "cpu")
+            cpu, _ := strconv.Atoi(cpustr)
+            ParseStatLine(line, m.cpus[cpu])
+        }
+    }
+}
+
+func (m *CpustatCollector) Close() {
+	return
+}
diff --git a/config.json b/config.json
index f2bba58..2bd044e 100644
--- a/config.json
+++ b/config.json
@@ -15,6 +15,7 @@
         "loadavg",
         "netstat",
         "ibstat",
-        "lustrestat"
+        "lustrestat",
+        "cpustat"
     ]
 }
diff --git a/metric-collector.go b/metric-collector.go
index dd5376c..aeaffd1 100644
--- a/metric-collector.go
+++ b/metric-collector.go
@@ -23,6 +23,7 @@ var Collectors = map[string]collectors.MetricGetter{
 	"netstat":    &collectors.NetstatCollector{},
 	"ibstat":     &collectors.InfinibandCollector{},
 	"lustrestat": &collectors.LustreCollector{},
+	"cpustat": &collectors.CpustatCollector{},
 }
 
 var Sinks = map[string]sinks.SinkFuncs{