app.go

package main

import (
	"fmt"
	"os"
	"strconv"

	log "github.com/sirupsen/logrus"
)

func main() {
	c := Config{
		Stdout: os.Stdout,
		Stdin:  os.Stdin,
		Stderr: os.Stderr,
		Args:   os.Args[1:],
	}
	os.Exit(run(c))
}

func run(c Config) (exitcode int) {
	var err error

	cmd, err := c.ParseArgs()
	if err != nil {
		goto ERROR
	}

	switch cmd {
	case CMD_HELP:
		help(c)

	case CMD_LIST:
		if err = list(c); err != nil {
			goto ERROR
		}

	case CMD_CONNECT:
		if err = connect(c); err != nil {
			goto ERROR
		}

	case CMD_DEAUTH:
		if err = deauth(c); err != nil {
			goto ERROR
		}

	default:
		log.Errorf("Undefined command: %s", cmd)
		goto ERROR
	}
	return 0

ERROR:
	log.Errorf("%v", err)
	return 1
}

func connect(c Config) error {
	con := &Connect{config: c}
	return con.Run()
}

func list(c Config) error {
	nova := NewNova(c.NetworkInterface)
	if err := nova.Init(c.AuthCache); err != nil {
		return err
	}

	machines, err := nova.List()
	if err != nil {
		return err
	}

	if len(machines) == 0 {
		fmt.Fprintf(os.Stdout, "No servers found.\n")
		return nil
	}

	width := 0
	for _, m := range machines {
		if len(m.Name) > width {
			width = len(m.Name)
		}
	}

	format := "%" + strconv.Itoa(-width) + "s\t%s\n"
	fmt.Fprintf(c.Stdout, format, "[Name]", "[IP Address]")
	for _, m := range machines {
		fmt.Fprintf(c.Stdout, format, m.Name, m.Ipaddr)
	}
	return nil
}

func help(c Config) {
	fmt.Fprintf(c.Stdout, `NAME:
	%s - A client program for OpenStack(Nova) that connect to your instance with the instance name.

USAGE:
	%s [ssh-options] user@instance-name [comamnd]

VERSION:
	%s

OPTIONS:
	--authcache: Store credentials to the cache file ($HOME/.novassh).
	--command:   Specify SSH command (default: "ssh").
	--console:   Use an serial console connection instead of SSH.
	--deauth:    Remove credential cache.
	--debug:     Output some debug messages.
	--list:      Display instances.
	--help:      Print this message.

    Any other options will pass to the SSH command.

ENVIRONMENTS:
	NOVASSH_COMMAND:   Specify SSH command (default: "ssh").
	NOVASSH_INTERFACE: Specify network interface of instance (default: blank strings which means the auto detection).

`, APPNAME, APPNAME, VERSION)
}

func deauth(c Config) error {
	nova := NewNova(c.NetworkInterface)
	return nova.RemoveCredentialCache()
}