#!/usr/bin/python
# Copyright (C) 2012-2015  Codethink Limited
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program.  If not, see <http://www.gnu.org/licenses/>.


'''A Morph deployment write extension for deploying to KVM+libvirt.

See file kvm.write.help for documentation

'''


import os
import re
import subprocess
import sys
import tempfile
import urlparse

import writeexts


class KvmPlusSshWriteExtension(writeexts.WriteExtension):

    location_pattern = '^/(?P<guest>[^/]+)(?P<path>/.+)$'

    def process_args(self, args):
        if len(args) != 2:
            raise writeexts.ExtensionError(
                'Wrong number of command line args')

        temp_root, location = args
        ssh_host, vm_name, vm_path = self.parse_location(location)
        autostart = self.get_environment_boolean('AUTOSTART')

        fd, raw_disk = tempfile.mkstemp()
        os.close(fd)
        self.create_local_system(temp_root, raw_disk)

        try:
            self.transfer(raw_disk, ssh_host, vm_path)
            self.create_libvirt_guest(ssh_host, vm_name, vm_path, autostart)
        except BaseException:
            sys.stderr.write('Error deploying to libvirt')
            os.remove(raw_disk)
            writeexts.ssh_runcmd(ssh_host, ['rm', '-f', vm_path])
            raise
        else:
            os.remove(raw_disk)

        self.status(
            msg='Virtual machine %(vm_name)s has been created',
            vm_name=vm_name)

    def parse_location(self, location):
        '''Parse the location argument to get relevant data.'''

        x = urlparse.urlparse(location)
        m = re.match('^/(?P<guest>[^/]+)(?P<path>/.+)$', x.path)
        return x.netloc, m.group('guest'), m.group('path')

    def transfer(self, raw_disk, ssh_host, vm_path):
        '''Transfer raw disk image to libvirt host.'''

        self.status(msg='Transferring disk image')

        xfer_hole_path = writeexts.get_data_path('xfer-hole')
        recv_hole = writeexts.get_data('recv-hole')

        ssh_remote_cmd = [
            'sh', '-c', recv_hole, 'dummy-argv0', 'file', vm_path
            ]

        xfer_hole_proc = subprocess.Popen(
            ['python', xfer_hole_path, raw_disk],
            stdout=subprocess.PIPE)
        recv_hole_proc = subprocess.Popen(
            ['ssh', ssh_host] + map(writeexts.shell_quote, ssh_remote_cmd),
            stdin=xfer_hole_proc.stdout)
        xfer_hole_proc.stdout.close()
        recv_hole_proc.communicate()

    def create_libvirt_guest(self, ssh_host, vm_name, vm_path, autostart):
        '''Create the libvirt virtual machine.'''

        self.status(msg='Creating libvirt/kvm virtual machine')

        attach_disks = self.parse_attach_disks()
        attach_opts = []
        for disk in attach_disks:
            attach_opts.extend(['--disk', 'path=%s' % disk])

        if 'NIC_CONFIG' in os.environ:
            nics = os.environ['NIC_CONFIG'].split()
            for nic in nics:
                attach_opts.extend(['--network', nic])

        ram_mebibytes = str(self.get_ram_size() / (1024**2))

        vcpu_count = str(self.get_vcpu_count())

        cmdline = ['virt-install', '--connect', 'qemu:///system',
                   '--import', '--name', vm_name, '--vnc',
                   '--ram', ram_mebibytes, '--vcpus', vcpu_count,
                   '--disk', 'path=%s,bus=ide' % vm_path] + attach_opts
        if not autostart:
            cmdline += ['--noreboot']
        writeexts.ssh_runcmd(ssh_host, cmdline)

        if autostart:
            writeexts.ssh_runcmd(ssh_host,
                                 ['virsh', '--connect', 'qemu:///system',
                                  'autostart', vm_name])

KvmPlusSshWriteExtension().run()