hakurei/cmd/app/run.go

package main

import (
	"context"
	"encoding/json"
	"os"
	"os/exec"
	"syscall"

	"hakurei.app/hst"
	"hakurei.app/message"
)

// run starts a container via cmd/hakurei and returns after it terminates.
func run(ctx context.Context, msg message.Msg, config *hst.Config) error {
	c, cancel := context.WithCancel(ctx)
	defer cancel()

	cmd := exec.CommandContext(c, "hakurei")
	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
	cmd.Cancel = func() error {
		return cmd.Process.Signal(syscall.SIGINT)
	}
	if msg.IsVerbose() {
		cmd.Args = append(cmd.Args, "-v")
	}
	cmd.Args = append(cmd.Args, "run", "3")

	r, w, err := os.Pipe()
	if err != nil {
		return err
	}
	cmd.ExtraFiles = append(cmd.ExtraFiles, r)

	if err = cmd.Start(); err != nil {
		_, _ = r.Close(), w.Close()
		return err
	}

	if err = r.Close(); err != nil {
		_ = w.Close()
		return err
	} else if err = json.NewEncoder(w).Encode(&config); err != nil {
		_ = w.Close()
		return err
	} else if err = w.Close(); err != nil {
		return err
	}

	return cmd.Wait()
}