The (unofficial) completed Golang code written in an UNIQLO Akamai PEACE FOR ALL T-shirt.

peace_for_all.go

package main

import (
	"fmt"
	"html"
	"log"
	"net/http"
	"strconv"
	"strings"
	"time"
)

type ControlMessage struct {
	Target string
	Count  int64
}

func main() {
	controlChannel := make(chan ControlMessage)
	workerCompleteChan := make(chan bool)
	statusPollChannel := make(chan chan bool)
	workerActive := false
	go admin(controlChannel, statusPollChannel)
	for {
		select {
		case respChan := <-statusPollChannel:
			respChan <- workerActive
		case msg := <-controlChannel:
			workerActive = true
			go doStuff(msg, workerCompleteChan)
		case status := <-workerCompleteChan:
			workerActive = status
		}
	}
}

func admin(cc chan ControlMessage, statusPollChannel chan chan bool) {
	http.HandleFunc("/admin", func(w http.ResponseWriter, r *http.Request) {
		hostTokens := strings.Split(r.Host, ":")
		r.ParseForm()
		count, err := strconv.ParseInt(r.FormValue("count"), 10, 32)
		if err != nil {
			fmt.Fprintf(w, "bad request")
			log.Print(hostTokens[0])
			log.Print(err.Error())
			return
		}
		msg := ControlMessage{
			Target: r.FormValue("target"),
			Count:  count,
		}
		cc <- msg
		fmt.Fprintf(
			w,
			"Control message issued for Target: %s, Count: %d",
			html.EscapeString(r.FormValue("target")),
			count,
		)
	})
	http.HandleFunc("/status", func(w http.ResponseWriter, r *http.Request) {
		reqChan := make(chan bool)
		statusPollChannel <- reqChan
		timeout := time.Tick(time.Second)
		for {
			select {
			case result := <-reqChan:
				if result {
					fmt.Fprintf(w, "ACTIVE")
				} else {
					fmt.Fprintf(w, "INACTIVE")
				}
				return
			case <-timeout:
				fmt.Fprintf(w, ".")
			}
		}
	})
	log.Print("Server waiting on http://localhost:8000")
	http.ListenAndServe(":8000", nil)
}

func doStuff(mes ControlMessage, workerCompleteChan chan bool) {
	for range mes.Count {
		time.Sleep(time.Second)
	}
	log.Printf("Stuff done for %s", mes.Target)
	workerCompleteChan <- false
}