path: root/nova/virt/baremetal/pxe.py

# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2012 Hewlett-Packard Development Company, L.P.
# Copyright (c) 2012 NTT DOCOMO, INC.
# All Rights Reserved.
#
#    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.

"""
Class for PXE bare-metal nodes.
"""

import os
import shutil

from nova.compute import instance_types
from nova import exception
from nova.openstack.common import cfg
from nova.openstack.common import fileutils
from nova.openstack.common import log as logging
from nova import utils
from nova.virt.baremetal import base
from nova.virt.baremetal import db
from nova.virt.baremetal import utils as bm_utils
from nova.virt.disk import api as disk


pxe_opts = [
    cfg.StrOpt('deploy_kernel',
               help='Default kernel image ID used in deployment phase'),
    cfg.StrOpt('deploy_ramdisk',
               help='Default ramdisk image ID used in deployment phase'),
    cfg.StrOpt('net_config_template',
               default='$pybasedir/nova/virt/baremetal/'
                            'net-dhcp.ubuntu.template',
               help='Template file for injected network config'),
    cfg.StrOpt('pxe_append_params',
               help='additional append parameters for baremetal PXE boot'),
    cfg.StrOpt('pxe_config_template',
               default='$pybasedir/nova/virt/baremetal/pxe_config.template',
               help='Template file for PXE configuration'),
    ]

LOG = logging.getLogger(__name__)

baremetal_group = cfg.OptGroup(name='baremetal',
                               title='Baremetal Options')

CONF = cfg.CONF
CONF.register_group(baremetal_group)
CONF.register_opts(pxe_opts, baremetal_group)
CONF.import_opt('use_ipv6', 'nova.netconf')

CHEETAH = None


def _get_cheetah():
    global CHEETAH
    if CHEETAH is None:
        from Cheetah.Template import Template as CHEETAH
    return CHEETAH


def build_pxe_config(deployment_id, deployment_key, deployment_iscsi_iqn,
                      deployment_aki_path, deployment_ari_path,
                      aki_path, ari_path):
    """Build the PXE config file for a node

    This method builds the PXE boot configuration file for a node,
    given all the required parameters.

    The resulting file has both a "deploy" and "boot" label, which correspond
    to the two phases of booting. This may be extended later.

    """
    LOG.debug(_("Building PXE config for deployment %s.") % deployment_id)
    pxe_options = {
            'deployment_id': deployment_id,
            'deployment_key': deployment_key,
            'deployment_iscsi_iqn': deployment_iscsi_iqn,
            'deployment_aki_path': deployment_aki_path,
            'deployment_ari_path': deployment_ari_path,
            'aki_path': aki_path,
            'ari_path': ari_path,
            'pxe_append_params': CONF.baremetal.pxe_append_params,
            }
    cheetah = _get_cheetah()
    pxe_config = str(cheetah(
            open(CONF.baremetal.pxe_config_template).read(),
            searchList=[{'pxe_options': pxe_options,
                         'ROOT': '${ROOT}',
            }]))
    return pxe_config


def build_network_config(network_info):
    # TODO(deva): fix assumption that device names begin with "eth"
    #             and fix assumption about ordering
    try:
        assert isinstance(network_info, list)
    except AssertionError:
        network_info = [network_info]
    interfaces = []
    for id, (network, mapping) in enumerate(network_info):
        address_v6 = None
        gateway_v6 = None
        netmask_v6 = None
        if CONF.use_ipv6:
            address_v6 = mapping['ip6s'][0]['ip']
            netmask_v6 = mapping['ip6s'][0]['netmask']
            gateway_v6 = mapping['gateway_v6']
        interface = {
                'name': 'eth%d' % id,
                'hwaddress': mapping['mac'],
                'address': mapping['ips'][0]['ip'],
                'gateway': mapping['gateway'],
                'netmask': mapping['ips'][0]['netmask'],
                'dns': ' '.join(mapping['dns']),
                'address_v6': address_v6,
                'gateway_v6': gateway_v6,
                'netmask_v6': netmask_v6,
            }
        interfaces.append(interface)

    cheetah = _get_cheetah()
    network_config = str(cheetah(
            open(CONF.baremetal.net_config_template).read(),
            searchList=[
                {'interfaces': interfaces,
                 'use_ipv6': CONF.use_ipv6,
                }
            ]))
    return network_config


def get_deploy_aki_id(instance):
    return instance.get('extra_specs', {}).\
                get('deploy_kernel_id', CONF.baremetal.deploy_kernel)


def get_deploy_ari_id(instance):
    return instance.get('extra_specs', {}).\
                get('deploy_ramdisk_id', CONF.baremetal.deploy_ramdisk)


def get_image_dir_path(instance):
    """Generate the dir for an instances disk."""
    return os.path.join(CONF.instances_path, instance['name'])


def get_image_file_path(instance):
    """Generate the full path for an instances disk."""
    return os.path.join(CONF.instances_path, instance['name'], 'disk')


def get_pxe_config_file_path(instance):
    """Generate the path for an instances PXE config file."""
    return os.path.join(CONF.baremetal.tftp_root, instance['uuid'], 'config')


def get_partition_sizes(instance):
    type_id = instance['instance_type_id']
    root_mb = instance['root_gb'] * 1024

    # NOTE(deva): is there a way to get swap_mb directly from instance?
    swap_mb = instance_types.get_instance_type(type_id)['swap']

    # NOTE(deva): For simpler code paths on the deployment side,
    #             we always create a swap partition. If the flavor
    #             does not specify any swap, we default to 1MB
    if swap_mb < 1:
        swap_mb = 1

    return (root_mb, swap_mb)


def get_pxe_mac_path(mac):
    """Convert a MAC address into a PXE config file name."""
    return os.path.join(
            CONF.baremetal.tftp_root,
            'pxelinux.cfg',
            "01-" + mac.replace(":", "-").lower()
        )


def get_tftp_image_info(instance):
    """Generate the paths for tftp files for this instance

    Raises NovaException if
    - instance does not contain kernel_id or ramdisk_id
    - deploy_kernel_id or deploy_ramdisk_id can not be read from
      instance['extra_specs'] and defaults are not set

    """
    image_info = {
            'kernel': [None, None],
            'ramdisk': [None, None],
            'deploy_kernel': [None, None],
            'deploy_ramdisk': [None, None],
            }
    try:
        image_info['kernel'][0] = str(instance['kernel_id'])
        image_info['ramdisk'][0] = str(instance['ramdisk_id'])
        image_info['deploy_kernel'][0] = get_deploy_aki_id(instance)
        image_info['deploy_ramdisk'][0] = get_deploy_ari_id(instance)
    except KeyError as e:
        pass

    missing_labels = []
    for label in image_info.keys():
        (uuid, path) = image_info[label]
        if uuid is None:
            missing_labels.append(label)
        else:
            image_info[label][1] = os.path.join(CONF.baremetal.tftp_root,
                            instance['uuid'], label)
    if missing_labels:
        raise exception.NovaException(_(
            "Can not activate PXE bootloader. The following boot parameters "
            "were not passed to baremetal driver: %s") % missing_labels)
    return image_info


class PXE(base.NodeDriver):
    """PXE bare metal driver."""

    def __init__(self):
        super(PXE, self).__init__()

    def _collect_mac_addresses(self, context, node):
        macs = []
        macs.append(db.bm_node_get(context, node['id'])['prov_mac_address'])
        for nic in db.bm_interface_get_all_by_bm_node_id(context, node['id']):
            if nic['address']:
                macs.append(nic['address'])
        macs.sort()
        return macs

    def _generate_udev_rules(self, context, node):
        # TODO(deva): fix assumption that device names begin with "eth"
        #             and fix assumption of ordering
        macs = self._collect_mac_addresses(context, node)
        rules = ''
        for (i, mac) in enumerate(macs):
            rules += 'SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ' \
                     'ATTR{address}=="%(mac)s", ATTR{dev_id}=="0x0", ' \
                     'ATTR{type}=="1", KERNEL=="eth*", NAME="%(name)s"\n' \
                     % {'mac': mac.lower(),
                        'name': 'eth%d' % i,
                        }
        return rules

    def _cache_tftp_images(self, context, instance, image_info):
        """Fetch the necessary kernels and ramdisks for the instance."""
        fileutils.ensure_tree(
                os.path.join(CONF.baremetal.tftp_root, instance['uuid']))

        LOG.debug(_("Fetching kernel and ramdisk for instance %s") %
                        instance['name'])
        for label in image_info.keys():
            (uuid, path) = image_info[label]
            bm_utils.cache_image(
                    context=context,
                    target=path,
                    image_id=uuid,
                    user_id=instance['user_id'],
                    project_id=instance['project_id'],
                )

    def _cache_image(self, context, instance, image_meta):
        """Fetch the instance's image from Glance

        This method pulls the relevant AMI and associated kernel and ramdisk,
        and the deploy kernel and ramdisk from Glance, and writes them
        to the appropriate places on local disk.

        Both sets of kernel and ramdisk are needed for PXE booting, so these
        are stored under CONF.baremetal.tftp_root.

        At present, the AMI is cached and certain files are injected.
        Debian/ubuntu-specific assumptions are made regarding the injected
        files. In a future revision, this functionality will be replaced by a
        more scalable and os-agnostic approach: the deployment ramdisk will
        fetch from Glance directly, and write its own last-mile configuration.

        """
        fileutils.ensure_tree(get_image_dir_path(instance))
        image_path = get_image_file_path(instance)

        LOG.debug(_("Fetching image %(ami)s for instance %(name)s") %
                        {'ami': image_meta['id'], 'name': instance['name']})
        bm_utils.cache_image(context=context,
                             target=image_path,
                             image_id=image_meta['id'],
                             user_id=instance['user_id'],
                             project_id=instance['project_id']
                        )

        return [image_meta['id'], image_path]

    def _inject_into_image(self, context, node, instance, network_info,
            injected_files=None, admin_password=None):
        """Inject last-mile configuration into instances image

        Much of this method is a hack around DHCP and cloud-init
        not working together with baremetal provisioning yet.

        """
        # NOTE(deva): We assume that if we're not using a kernel,
        #             then the target partition is the first partition
        partition = None
        if not instance['kernel_id']:
            partition = "1"

        ssh_key = None
        if 'key_data' in instance and instance['key_data']:
            ssh_key = str(instance['key_data'])

        if injected_files is None:
            injected_files = []

        net_config = build_network_config(network_info)
        udev_rules = self._generate_udev_rules(context, node)
        injected_files.append(
                ('/etc/udev/rules.d/70-persistent-net.rules', udev_rules))

        if instance['hostname']:
            injected_files.append(('/etc/hostname', instance['hostname']))

        LOG.debug(_("Injecting files into image for instance %(name)s") %
                        {'name': instance['name']})

        bm_utils.inject_into_image(
                    image=get_image_file_path(instance),
                    key=ssh_key,
                    net=net_config,
                    metadata=instance['metadata'],
                    admin_password=admin_password,
                    files=injected_files,
                    partition=partition,
                )

    def cache_images(self, context, node, instance,
            admin_password, image_meta, injected_files, network_info):
        """Prepare all the images for this instance."""
        tftp_image_info = get_tftp_image_info(instance)
        self._cache_tftp_images(context, instance, tftp_image_info)

        self._cache_image(context, instance, image_meta)
        self._inject_into_image(context, node, instance, network_info,
                injected_files, admin_password)

    def destroy_images(self, context, node, instance):
        """Delete instance's image file."""
        bm_utils.unlink_without_raise(get_image_file_path(instance))
        bm_utils.unlink_without_raise(get_image_dir_path(instance))

    def activate_bootloader(self, context, node, instance):
        """Configure PXE boot loader for an instance

        Kernel and ramdisk images are downloaded by cache_tftp_images,
        and stored in /tftpboot/{uuid}/

        This method writes the instances config file, and then creates
        symlinks for each MAC address in the instance.

        By default, the complete layout looks like this:

        /tftpboot/
            ./{uuid}/
                 kernel
                 ramdisk
                 deploy_kernel
                 deploy_ramdisk
                 config
            ./pxelinux.cfg/
                 {mac} -> ../{uuid}/config

        """
        image_info = get_tftp_image_info(instance)
        (root_mb, swap_mb) = get_partition_sizes(instance)
        pxe_config_file_path = get_pxe_config_file_path(instance)
        image_file_path = get_image_file_path(instance)

        deployment_key = bm_utils.random_alnum(32)
        deployment_iscsi_iqn = "iqn-%s" % instance['uuid']
        deployment_id = db.bm_deployment_create(
                            context,
                            deployment_key,
                            image_file_path,
                            pxe_config_file_path,
                            root_mb,
                            swap_mb
                        )
        pxe_config = build_pxe_config(
                    deployment_id,
                    deployment_key,
                    deployment_iscsi_iqn,
                    image_info['deploy_kernel'][1],
                    image_info['deploy_ramdisk'][1],
                    image_info['kernel'][1],
                    image_info['ramdisk'][1],
                )
        bm_utils.write_to_file(pxe_config_file_path, pxe_config)

        macs = self._collect_mac_addresses(context, node)
        for mac in macs:
            mac_path = get_pxe_mac_path(mac)
            bm_utils.unlink_without_raise(mac_path)
            bm_utils.create_link_without_raise(pxe_config_file_path, mac_path)

    def deactivate_bootloader(self, context, node, instance):
        """Delete PXE bootloader images and config."""
        try:
            image_info = get_tftp_image_info(instance)
        except exception.NovaException:
            pass
        else:
            for label in image_info.keys():
                (uuid, path) = image_info[label]
                bm_utils.unlink_without_raise(path)

        bm_utils.unlink_without_raise(get_pxe_config_file_path(instance))
        try:
            macs = self._collect_mac_addresses(context, node)
        except exception.DBError:
            pass
        else:
            for mac in macs:
                bm_utils.unlink_without_raise(get_pxe_mac_path(mac))

        bm_utils.unlink_without_raise(
                os.path.join(CONF.baremetal.tftp_root, instance['uuid']))

    def activate_node(self, context, node, instance):
        pass

    def deactivate_node(self, context, node, instance):
        pass