Include CPU usage percent with procstat data

closes #484

agent.go

@@ -216,7 +216,7 @@ func (a *Agent) Test() error {
 		// Special instructions for some inputs. cpu, for example, needs to be
 		// run twice in order to return cpu usage percentages.
 		switch input.Name {
-		case "cpu", "mongodb":
+		case "cpu", "mongodb", "procstat":
 			time.Sleep(500 * time.Millisecond)
 			fmt.Printf("* Plugin: %s, Collection 2\n", input.Name)
 			if err := input.Input.Gather(acc); err != nil {

plugins/inputs/procstat/procstat.go

@@ -18,10 +18,14 @@ type Procstat struct {
 	Exe     string
 	Pattern string
 	Prefix  string
+
+	pidmap map[int32]*process.Process
 }
 
 func NewProcstat() *Procstat {
-	return &Procstat{}
+	return &Procstat{
+		pidmap: make(map[int32]*process.Process),
+	}
 }
 
 var sampleConfig = `
@@ -46,12 +50,12 @@ func (_ *Procstat) Description() string {
 }
 
 func (p *Procstat) Gather(acc inputs.Accumulator) error {
-	procs, err := p.createProcesses()
+	err := p.createProcesses()
 	if err != nil {
 		log.Printf("Error: procstat getting process, exe: [%s] pidfile: [%s] pattern: [%s] %s",
 			p.Exe, p.PidFile, p.Pattern, err.Error())
 	} else {
-		for _, proc := range procs {
+		for _, proc := range p.pidmap {
 			p := NewSpecProcessor(p.Prefix, acc, proc)
 			p.pushMetrics()
 		}
@@ -60,8 +64,7 @@ func (p *Procstat) Gather(acc inputs.Accumulator) error {
 	return nil
 }
 
-func (p *Procstat) createProcesses() ([]*process.Process, error) {
-	var out []*process.Process
+func (p *Procstat) createProcesses() error {
 	var errstring string
 	var outerr error
 
@@ -71,19 +74,22 @@ func (p *Procstat) createProcesses() ([]*process.Process, error) {
 	}
 
 	for _, pid := range pids {
-		p, err := process.NewProcess(int32(pid))
-		if err == nil {
-			out = append(out, p)
-		} else {
-			errstring += err.Error() + " "
+		_, ok := p.pidmap[pid]
+		if !ok {
+			proc, err := process.NewProcess(pid)
+			if err == nil {
+				p.pidmap[pid] = proc
+			} else {
+				errstring += err.Error() + " "
+			}
 		}
 	}
 
 	if errstring != "" {
 		outerr = fmt.Errorf("%s", errstring)
 	}
 
-	return out, outerr
+	return outerr
 }
 
 func (p *Procstat) getAllPids() ([]int32, error) {

plugins/inputs/procstat/procstat_test.go

@@ -6,6 +6,7 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/shirou/gopsutil/process"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -23,6 +24,7 @@ func TestGather(t *testing.T) {
 	p := Procstat{
 		PidFile: file.Name(),
 		Prefix:  "foo",
+		pidmap:  make(map[int32]*process.Process),
 	}
 	p.Gather(&acc)
 	assert.True(t, acc.HasFloatField("procstat", "foo_cpu_time_user"))

plugins/inputs/procstat/spec_processor.go

@@ -3,6 +3,7 @@ package procstat
 import (
 	"fmt"
 	"log"
+	"time"
 
 	"github.com/shirou/gopsutil/process"
 
@@ -40,7 +41,7 @@ func NewSpecProcessor(
 	tags := make(map[string]string)
 	tags["pid"] = fmt.Sprintf("%v", p.Pid)
 	if name, err := p.Name(); err == nil {
-		tags["name"] = name
+		tags["process_name"] = name
 	}
 	return &SpecProcessor{
 		Prefix: prefix,
@@ -113,10 +114,18 @@ func (p *SpecProcessor) pushCPUStats() error {
 	p.add("cpu_time_iowait", cpu_time.Iowait)
 	p.add("cpu_time_irq", cpu_time.Irq)
 	p.add("cpu_time_soft_irq", cpu_time.Softirq)
-	p.add("cpu_time_soft_steal", cpu_time.Steal)
-	p.add("cpu_time_soft_stolen", cpu_time.Stolen)
-	p.add("cpu_time_soft_guest", cpu_time.Guest)
-	p.add("cpu_time_soft_guest_nice", cpu_time.GuestNice)
+	p.add("cpu_time_steal", cpu_time.Steal)
+	p.add("cpu_time_stolen", cpu_time.Stolen)
+	p.add("cpu_time_guest", cpu_time.Guest)
+	p.add("cpu_time_guest_nice", cpu_time.GuestNice)
+
+	cpu_perc, err := p.proc.CPUPercent(time.Duration(0))
+	if err != nil {
+		return err
+	} else if cpu_perc == 0 {
+		return nil
+	}
+	p.add("cpu_usage", cpu_perc)
 
 	return nil
 }