from base import Task
from common import phases
from common.tasks.initd import InstallInitScripts
import os


class AddSudoPackage(Task):
	description = 'Adding ``sudo\'\' to the image packages'
	phase = phases.preparation

	def run(self, info):
		info.packages.add('sudo')


class CreateAdminUser(Task):
	description = 'Creating the admin user'
	phase = phases.system_modification

	def run(self, info):
		from common.tools import log_check_call
		log_check_call(['/usr/sbin/chroot', info.root,
		                '/usr/sbin/useradd',
		                '--create-home', '--shell', '/bin/bash',
		                info.manifest.plugins['admin_user']['username']])


class PasswordlessSudo(Task):
	description = 'Allowing the admin user to use sudo without a password'
	phase = phases.system_modification

	def run(self, info):
		sudo_admin_path = os.path.join(info.root, 'etc/sudoers.d/99_admin')
		username = info.manifest.plugins['admin_user']['username']
		with open(sudo_admin_path, 'w') as sudo_admin:
			sudo_admin.write('{username} ALL=(ALL) NOPASSWD:ALL'.format(username=username))
		import stat
		ug_read_only = (stat.S_IRUSR | stat.S_IRGRP)
		os.chmod(sudo_admin_path, ug_read_only)


class AdminUserCredentials(Task):
	description = 'Modifying ec2-get-credentials to copy the ssh public key to the admin user'
	phase = phases.system_modification
	predecessors = [InstallInitScripts]

	def run(self, info):
		from common.tools import sed_i
		getcreds_path = os.path.join(info.root, 'etc/init.d/ec2-get-credentials')
		username = info.manifest.plugins['admin_user']['username']
		sed_i(getcreds_path, 'username=\'root\'', 'username=\'{username}\''.format(username=username))


class DisableRootLogin(Task):
	description = 'Disabling SSH login for root'
	phase = phases.system_modification

	def run(self, info):
		from subprocess import CalledProcessError
		from common.tools import log_check_call
		try:
			log_check_call(['/usr/sbin/chroot', info.root,
			                '/usr/bin/dpkg-query', '-W', 'openssh-server'])
			from common.tools import sed_i
			sshdconfig_path = os.path.join(info.root, 'etc/ssh/sshd_config')
			sed_i(sshdconfig_path, 'PermitRootLogin yes', 'PermitRootLogin no')
		except CalledProcessError:
			import logging
			logging.getLogger(__name__).warn('The OpenSSH server has not been installed, '
			                                 'not disabling SSH root login.')