Measure hyperkit host CPU load

hyperkit-cpu.go

package main

import (
        "fmt"
        "os/exec"
        "strconv"
        "strings"
        "time"
)

const (
        linuxkit = "/usr/local/bin/hyperkit"
        desktop = "com.docker.hyperkit"
        bigsur = "com.apple.Virtualization.VirtualMachine"
)

func main() {
        binary := desktop
        out, err := exec.Command("/bin/sh", "-c", `ps -o pid,args -x | grep ` + binary + ` | grep -v grep | cut -f 1 -d " "`).CombinedOutput()
        if err != nil {
                panic(err)
        }
        pid := strings.TrimSpace(string(out))
        fmt.Printf("Monitoring %s pid %s\n", binary, pid)
        fmt.Printf("Waiting for 60s for it to settle\n")
        time.Sleep(60 * time.Second)
        total := float64(0.0)
        for i := 0; i < 60; i++ {
                x := cpu(pid)
                total += x
                fmt.Printf("%d / 60 was %v\n", i, x)
                time.Sleep(time.Second)
        }
        fmt.Printf("%f\n", total/60.0)
}

func cpu(pid string) float64 {
        out, err := exec.Command("/bin/sh", "-c", "ps -o %cpu -p "+pid+" | tail -1").CombinedOutput()
        if err != nil {
                panic(err)
        }
        percent, err := strconv.ParseFloat(strings.TrimSpace(string(out)), 64)
        if err != nil {
                panic(err)
        }
        return percent
}