os/cmd/control/autologin.go

package control

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"

	"github.com/codegangsta/cli"
	"github.com/rancher/os/config"
	"github.com/rancher/os/log"
)

func AutologinMain() {
	log.InitLogger()
	app := cli.NewApp()

	app.Name = os.Args[0]
	app.Usage = "autologin console"
	app.Version = config.Version
	app.Author = "Rancher Labs, Inc."
	app.Email = "sven@rancher.com"
	app.EnableBashCompletion = true
	app.Action = autologinAction
	app.HideHelp = true
	app.Run(os.Args)
}

func autologinAction(c *cli.Context) error {
	cmd := exec.Command("/bin/stty", "sane")
	cmd.Stderr = os.Stderr
	cmd.Stdout = os.Stdout
	cmd.Stdin = os.Stdin
	if err := cmd.Run(); err != nil {
		log.Error(err)
	}

	usertty := ""
	user := "root"
	tty := ""
	if c.NArg() > 0 {
		usertty = c.Args().Get(0)
		s := strings.SplitN(usertty, ":", 2)
		user = s[0]
		if len(s) > 1 {
			tty = s[1]
		}
	}

	mode := filepath.Base(os.Args[0])
	console := CurrentConsole()

	cfg := config.LoadConfig()
	// replace \n and \l
	banner := config.Banner
	banner = strings.Replace(banner, "\\v", config.Version, -1)
	banner = strings.Replace(banner, "\\s", "RancherOS "+runtime.GOARCH, -1)
	banner = strings.Replace(banner, "\\r", config.GetKernelVersion(), -1)
	banner = strings.Replace(banner, "\\n", cfg.Hostname, -1)
	banner = strings.Replace(banner, "\\l", tty, -1)
	banner = strings.Replace(banner, "\\\\", "\\", -1)
	banner = banner + "\n"
	banner = banner + "Autologin " + console + "\n"
	fmt.Printf(banner)

	loginBin := ""
	args := []string{}
	if console == "centos" || console == "fedora" ||
		mode == "recovery" {
		// For some reason, centos and fedora ttyS0 and tty1 don't work with `login -f rancher`
		// until I make time to read their source, lets just give us a way to get work done
		loginBin = "bash"
		args = append(args, "--login")
		if mode == "recovery" {
			os.Setenv("PROMPT_COMMAND", `echo "[`+fmt.Sprintf("Recovery console %s@%s:${PWD}", user, cfg.Hostname)+`]"`)
		}
	} else {
		loginBin = "login"
		args = append(args, "-f", user)
		// TODO: add a PROMPT_COMMAND if we haven't switch-rooted
	}

	loginBinPath, err := exec.LookPath(loginBin)
	if err != nil {
		fmt.Printf("error finding %s in path: %s", cmd.Args[0], err)
		return err
	}
	os.Setenv("TERM", "linux")

	// Causes all sorts of issues
	//return syscall.Exec(loginBinPath, args, os.Environ())
	cmd = exec.Command(loginBinPath, args...)
	cmd.Env = os.Environ()

	cmd.Stderr = os.Stderr
	cmd.Stdout = os.Stdout
	cmd.Stdin = os.Stdin
	if err := cmd.Run(); err != nil {
		log.Errorf("\nError starting %s: %s", cmd.Args[0], err)
	}
	return nil
}