runner.go

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/exec"
	"strings"
	"syscall"
	"time"

	"github.com/oklog/run"
)

func main() {

	args := os.Args[1:]
	fmt.Println("[runner] starting:", strings.Join(args, ","))
	cmd := exec.CommandContext(context.Background(), "envoy", args...)

	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.SysProcAttr = &syscall.SysProcAttr{
		Setpgid: true,
	}

	var g run.Group
	{
		g.Add(func() error {

			return cmd.Run()
		}, func(err error) {
			fmt.Println("[runner] cancelling")
			time.Sleep(1 * time.Second)

			resp, err = http.Post("http://fly-local-6pn:9901/drain_listeners?graceful", "application/json", nil)
			if err != nil {
				log.Println(err)
				os.Exit(1)
			}
			fmt.Println("[runner] GOT HTTP: ", resp.StatusCode)
			fmt.Println("[runner] done drain_listeners?graceful, sleeping 10s")
			time.Sleep(10 * time.Second)

			if err := syscall.Kill(cmd.Process.Pid, syscall.SIGKILL); err != nil {
				fmt.Println("[runner] failed to kill envoy", err)
				os.Exit(1)
			}
			fmt.Println("[runner] exiting")
			os.Exit(0)
		})

		ctx, cancel := context.WithCancel(context.Background())
		defer cancel()
		execute, interrupt := run.SignalHandler(ctx, syscall.SIGINT)
		g.Add(execute, interrupt)
	}
	log.Printf("exit: %v\n", g.Run())

}