#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2012, Jeroen Hoekx <jeroen@hoekx.be>
#
# This file is part of Ansible
#
# Ansible 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, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.

DOCUMENTATION = '''
---
author: Jeroen Hoekx
module: virt_boot
short_description: Define libvirt boot parameters
description:
  - "This module configures the boot order or boot media of a libvirt virtual
     machine. A guest can be configured to boot from network, hard disk, floppy,
     cdrom or a direct kernel boot. Specific media can be attached for cdrom, 
     floppy and direct kernel boot."
  - This module requires the libvirt module.
version_added: "0.8"
options:
  domain:
    description:
    - The name of the libvirt domain.
    required: true
  boot:
    description:
    - "Specify the boot order of the virtual machine. This is a comma-separated 
      list of: I(fd), I(hd), I(cdrom) and I(network)."
    required: false
  bootmenu:
    choices: [ "yes", "no" ]
    description:
    - Enable or disable the boot menu.
    required: false
  kernel:
    description:
    - The path of the kernel to boot.
    required: false
  initrd:
    description:
    - The path of the initrd to boot.
    required: false
  cmdline:
    description:
    - The command line to boot the kernel with.
    required: false
  device:
    default: hdc
    description:
    - The libvirt device name of the cdrom/floppy.
    required: false
  image:
    description:
    - The image to connect to the cdrom/floppy device.
    required: false
  start:
    choices: [ "yes", "no" ]
    default: yes
    description:
    - Start the guest after configuration.
    required: false
examples:
  - description: Boot from a cdrom image.
    code: virt_boot domain=archrear image=/srv/rear/archrear/rear-archrear.iso boot=cdrom
  - description: Boot from the local disk.
    code: virt_boot domain=archrear boot=hd
  - description: Boot a specific kernel with a special command line.
    code: virt_boot domain=archrear kernel={{ storage }}/kernel-archrear initrd={{ storage }}/initramfs-archrear.img cmdline="root=/dev/ram0 vga=normal rw"
  - description: Boot from the harddisk and if that fails from the network.
    code: virt_boot domain=archrear boot=hd,network
  - description: Enable the boot menu.
    code: virt_boot domain=archrear bootmenu=yes
requirements: [ "libvirt" ]
notes:
  - Run this on the libvirt host.
  - I(kernel) and I(boot) are mutually exclusive.
  - This module does not change a running system. A shutdown/restart is required.
'''

import sys

try:
    import xml.etree.ElementTree as ET
    from xml.etree.ElementTree import SubElement
except ImportError:
    try:
        import elementtree.ElementTree as ET
        from elementtree.ElementTree import SubElement
    except ImportError:
        print "failed=True msg='ElementTree python module unavailable'"

try:
    import libvirt
except ImportError:
    print "failed=True msg='libvirt python module unavailable'"
    sys.exit(1)

from ansible.module_utils.basic import AnsibleModule

def get_disk(doc, device):
    for disk in doc.findall('.//disk'):
        target = disk.find('target')
        if target is not None:
            if target.get('dev','') == device:
                return disk

def attach_disk(domain, doc, device, image):
    disk = get_disk(doc, device)
    if disk is not None:
        source = disk.find('source')
        if source is not None and source.get('file') == image:
            return False

    xml = '''<disk type="file" device="cdrom">
                <driver name="qemu" type="raw"/>
                <source file="{path}"/>
                <target bus="ide" dev="{dev}"/>
             </disk>'''.format(path=image, dev=device)
    domain.updateDeviceFlags(xml, libvirt.VIR_DOMAIN_AFFECT_CONFIG)
    return True

def detach_disk(domain, doc, device):
    disk = get_disk(doc, device)
    if disk is not None:
        source = disk.find('source')
        if source is not None and 'file' in source.attrib:
            del source.attrib['file']
            domain.updateDeviceFlags(ET.tostring(disk), libvirt.VIR_DOMAIN_AFFECT_CONFIG)
            return True
    return False

def main():

    module = AnsibleModule(
        argument_spec = dict(
            domain=dict(required=True, aliases=['guest']),
            boot=dict(),
            bootmenu=dict(type='bool'),
            kernel=dict(),
            initrd=dict(),
            cmdline=dict(),
            device=dict(default='hdc'),
            image=dict(),
            start=dict(type='bool', default='yes'),
        ),
        required_one_of = [['boot','kernel','image','bootmenu']],
        mutually_exclusive = [['boot','kernel']]
    )

    params = module.params

    domain_name = params['domain']

    bootmenu = module.boolean(params['bootmenu'])

    boot = params['boot']
    kernel = params['kernel']
    initrd = params['initrd']
    cmdline = params['cmdline']

    device = params['device']
    image = params['image']

    start = module.boolean(params['start'])

    changed = False

    conn = libvirt.open("qemu:///system")
    domain = conn.lookupByName(domain_name)

    doc = ET.fromstring( domain.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE) )

    ### Connect image
    if image:
        changed = changed or attach_disk(domain, doc, device, image)
        if not boot and not kernel:
            module.exit_json(changed=changed, image=image, device=device)
    else:
        changed = changed or detach_disk(domain, doc, device)

    if changed:
        doc = ET.fromstring( domain.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE) )

    ### Boot ordering
    os = doc.find('os')
    boot_list = os.findall('boot')
    kernel_el = os.find('kernel')
    initrd_el = os.find('initrd')
    cmdline_el = os.find('cmdline')

    ### traditional boot
    if boot:
        if kernel_el is not None:
            changed = True
            os.remove(kernel_el)
        if initrd_el is not None:
            changed = True
            os.remove(initrd_el)
        if cmdline_el is not None:
            changed = True
            os.remove(cmdline_el)

        items = boot.split(',')
        if boot_list:
            needs_change = False
            if len(items) == len(boot_list):
                for (boot_el, dev) in zip(boot_list, items):
                    if boot_el.get('dev') != dev:
                        needs_change = True
            else:
                needs_change = True

            if needs_change:
                changed = True
                for boot_el in boot_list:
                    os.remove(boot_el)
                for item in items:
                    boot_el = SubElement(os, 'boot')
                    boot_el.set('dev', item)
        else:
            changed = True
            for item in items:
                boot_el = SubElement(os, 'boot')
                boot_el.set('dev', item)
    ### direct kernel boot
    elif kernel:
        if boot_list:
            ### libvirt alwas adds boot=hd using direct kernel boot
            if not (len(boot_list)==1 and boot_list[0].get('dev')=='hd'):
                changed = True
                for boot_el in boot_list:
                    os.remove(boot_el)

        if kernel_el is not None:
            if kernel_el.text != kernel:
                changed = True
                kernel_el.text = kernel
        else:
            changed = True
            kernel_el = SubElement(os, 'kernel')
            kernel_el.text = kernel

        if initrd_el is not None:
            if initrd_el.text != initrd:
                changed = True
                initrd_el.text = initrd
        else:
            changed = True
            initrd_el = SubElement(os, 'initrd')
            initrd_el.text = initrd

        if cmdline_el is not None:
            if cmdline_el.text != cmdline:
                changed = True
                cmdline_el.text = cmdline
        else:
            changed = True
            cmdline_el = SubElement(os, 'cmdline')
            cmdline_el.text = cmdline

    ### Enable/disable bootmenu
    bootmenu_el = os.find('bootmenu')
    if bootmenu and bootmenu_el is not None:
        bootmenu_enabled = bootmenu_el.get('enable')
        if bootmenu_enabled != 'yes':
            changed = True
            bootmenu_el.set('enable', 'yes')
    elif bootmenu:
        bootmenu_el = SubElement(os, 'bootmenu')
        bootmenu_el.set('enable', 'yes')
        changed = True
    elif bootmenu_el is not None:
        os.remove(bootmenu_el)
        changed = True

    ### save back
    conn.defineXML( ET.tostring(doc) )

    if start and not domain.isActive():
        changed = True
        domain.create()

    module.exit_json(changed=changed)

if __name__ == '__main__':
    main()
