cloudinit/system/user.go

/*
   Copyright 2014 CoreOS, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package system

import (
	"fmt"
	"log"
	"os/exec"
	"os/user"
	"strings"
)

type User struct {
	Name                string   `yaml:"name"`
	PasswordHash        string   `yaml:"passwd"`
	SSHAuthorizedKeys   []string `yaml:"ssh-authorized-keys"`
	SSHImportGithubUser string   `yaml:"coreos-ssh-import-github"`
	SSHImportURL        string   `yaml:"coreos-ssh-import-url"`
	GECOS               string   `yaml:"gecos"`
	Homedir             string   `yaml:"homedir"`
	NoCreateHome        bool     `yaml:"no-create-home"`
	PrimaryGroup        string   `yaml:"primary-group"`
	Groups              []string `yaml:"groups"`
	NoUserGroup         bool     `yaml:"no-user-group"`
	System              bool     `yaml:"system"`
	NoLogInit           bool     `yaml:"no-log-init"`
}

func UserExists(u *User) bool {
	_, err := user.Lookup(u.Name)
	return err == nil
}

func CreateUser(u *User) error {
	args := []string{}

	if u.PasswordHash != "" {
		args = append(args, "--password", u.PasswordHash)
	} else {
		args = append(args, "--password", "*")
	}

	if u.GECOS != "" {
		args = append(args, "--comment", fmt.Sprintf("%q", u.GECOS))
	}

	if u.Homedir != "" {
		args = append(args, "--home-dir", u.Homedir)
	}

	if u.NoCreateHome {
		args = append(args, "--no-create-home")
	} else {
		args = append(args, "--create-home")
	}

	if u.PrimaryGroup != "" {
		args = append(args, "--gid", u.PrimaryGroup)
	}

	if len(u.Groups) > 0 {
		args = append(args, "--groups", strings.Join(u.Groups, ","))
	}

	if u.NoUserGroup {
		args = append(args, "--no-user-group")
	}

	if u.System {
		args = append(args, "--system")
	}

	if u.NoLogInit {
		args = append(args, "--no-log-init")
	}

	args = append(args, u.Name)

	output, err := exec.Command("useradd", args...).CombinedOutput()
	if err != nil {
		log.Printf("Command 'useradd %s' failed: %v\n%s", strings.Join(args, " "), err, output)
	}
	return err
}

func SetUserPassword(user, hash string) error {
	cmd := exec.Command("/usr/sbin/chpasswd", "-e")

	stdin, err := cmd.StdinPipe()
	if err != nil {
		return err
	}

	err = cmd.Start()
	if err != nil {
		log.Fatal(err)
	}

	arg := fmt.Sprintf("%s:%s", user, hash)
	_, err = stdin.Write([]byte(arg))
	if err != nil {
		return err
	}
	stdin.Close()

	err = cmd.Wait()
	if err != nil {
		return err
	}

	return nil
}