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

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.

"""
Cloud Controller: Implementation of EC2 REST API calls, which are
dispatched to other nodes via AMQP RPC. State is via distributed
datastore.
"""

import base64
import re
import time
import urllib

from nova.api.ec2 import ec2utils
from nova.api.ec2 import inst_state
from nova.api import validator
from nova import block_device
from nova import compute
from nova.compute import instance_types
from nova.compute import vm_states
from nova import db
from nova import exception
from nova import flags
from nova.image import s3
from nova import log as logging
from nova import network
from nova.openstack.common import importutils
from nova import quota
from nova import utils
from nova import volume


FLAGS = flags.FLAGS

LOG = logging.getLogger(__name__)


def validate_ec2_id(val):
    if not validator.validate_str()(val):
        raise exception.InvalidInstanceIDMalformed(val)
    try:
        ec2utils.ec2_id_to_id(val)
    except exception.InvalidEc2Id:
        raise exception.InvalidInstanceIDMalformed(val)


# EC2 API can return the following values as documented in the EC2 API
# http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/
#    ApiReference-ItemType-InstanceStateType.html
# pending 0 | running 16 | shutting-down 32 | terminated 48 | stopping 64 |
# stopped 80
_STATE_DESCRIPTION_MAP = {
    None: inst_state.PENDING,
    vm_states.ACTIVE: inst_state.RUNNING,
    vm_states.BUILDING: inst_state.PENDING,
    vm_states.REBUILDING: inst_state.PENDING,
    vm_states.DELETED: inst_state.TERMINATED,
    vm_states.SOFT_DELETE: inst_state.TERMINATED,
    vm_states.STOPPED: inst_state.STOPPED,
    vm_states.SHUTOFF: inst_state.SHUTOFF,
    vm_states.MIGRATING: inst_state.MIGRATE,
    vm_states.RESIZING: inst_state.RESIZE,
    vm_states.PAUSED: inst_state.PAUSE,
    vm_states.SUSPENDED: inst_state.SUSPEND,
    vm_states.RESCUED: inst_state.RESCUE,
}


def _state_description(vm_state, shutdown_terminate):
    """Map the vm state to the server status string"""
    if (vm_state == vm_states.SHUTOFF and
        not shutdown_terminate):
            name = inst_state.STOPPED
    else:
        name = _STATE_DESCRIPTION_MAP.get(vm_state, vm_state)

    return {'code': inst_state.name_to_code(name),
            'name': name}


def _parse_block_device_mapping(bdm):
    """Parse BlockDeviceMappingItemType into flat hash
    BlockDevicedMapping.<N>.DeviceName
    BlockDevicedMapping.<N>.Ebs.SnapshotId
    BlockDevicedMapping.<N>.Ebs.VolumeSize
    BlockDevicedMapping.<N>.Ebs.DeleteOnTermination
    BlockDevicedMapping.<N>.Ebs.NoDevice
    BlockDevicedMapping.<N>.VirtualName
    => remove .Ebs and allow volume id in SnapshotId
    """
    ebs = bdm.pop('ebs', None)
    if ebs:
        ec2_id = ebs.pop('snapshot_id', None)
        if ec2_id:
            id = ec2utils.ec2_vol_id_to_uuid(ec2_id)
            if ec2_id.startswith('snap-'):
                bdm['snapshot_id'] = id
            elif ec2_id.startswith('vol-'):
                bdm['volume_id'] = id
            ebs.setdefault('delete_on_termination', True)
        bdm.update(ebs)
    return bdm


def _properties_get_mappings(properties):
    return block_device.mappings_prepend_dev(properties.get('mappings', []))


def _format_block_device_mapping(bdm):
    """Contruct BlockDeviceMappingItemType
    {'device_name': '...', 'snapshot_id': , ...}
    => BlockDeviceMappingItemType
    """
    keys = (('deviceName', 'device_name'),
             ('virtualName', 'virtual_name'))
    item = {}
    for name, k in keys:
        if k in bdm:
            item[name] = bdm[k]
    if bdm.get('no_device'):
        item['noDevice'] = True
    if ('snapshot_id' in bdm) or ('volume_id' in bdm):
        ebs_keys = (('snapshotId', 'snapshot_id'),
                    ('snapshotId', 'volume_id'),        # snapshotId is abused
                    ('volumeSize', 'volume_size'),
                    ('deleteOnTermination', 'delete_on_termination'))
        ebs = {}
        for name, k in ebs_keys:
            if k in bdm:
                if k == 'snapshot_id':
                    ebs[name] = ec2utils.id_to_ec2_snap_id(bdm[k])
                elif k == 'volume_id':
                    ebs[name] = ec2utils.id_to_ec2_vol_id(bdm[k])
                else:
                    ebs[name] = bdm[k]
        assert 'snapshotId' in ebs
        item['ebs'] = ebs
    return item


def _format_mappings(properties, result):
    """Format multiple BlockDeviceMappingItemType"""
    mappings = [{'virtualName': m['virtual'], 'deviceName': m['device']}
                for m in _properties_get_mappings(properties)
                if block_device.is_swap_or_ephemeral(m['virtual'])]

    block_device_mapping = [_format_block_device_mapping(bdm) for bdm in
                            properties.get('block_device_mapping', [])]

    # NOTE(yamahata): overwrite mappings with block_device_mapping
    for bdm in block_device_mapping:
        for i in range(len(mappings)):
            if bdm['deviceName'] == mappings[i]['deviceName']:
                del mappings[i]
                break
        mappings.append(bdm)

    # NOTE(yamahata): trim ebs.no_device == true. Is this necessary?
    mappings = [bdm for bdm in mappings if not (bdm.get('noDevice', False))]

    if mappings:
        result['blockDeviceMapping'] = mappings


class CloudController(object):
    """ CloudController provides the critical dispatch between
 inbound API calls through the endpoint and messages
 sent to the other nodes.
"""
    def __init__(self):
        self.image_service = s3.S3ImageService()
        self.network_api = network.API()
        self.volume_api = volume.API()
        self.compute_api = compute.API(network_api=self.network_api,
                                       volume_api=self.volume_api)
        self.keypair_api = compute.api.KeypairAPI()
        self.sgh = importutils.import_object(FLAGS.security_group_handler)

    def __str__(self):
        return 'CloudController'

    def _get_image_state(self, image):
        # NOTE(vish): fallback status if image_state isn't set
        state = image.get('status')
        if state == 'active':
            state = 'available'
        return image['properties'].get('image_state', state)

    def describe_availability_zones(self, context, **kwargs):
        if ('zone_name' in kwargs and
            'verbose' in kwargs['zone_name'] and
            context.is_admin):
            return self._describe_availability_zones_verbose(context,
                                                             **kwargs)
        else:
            return self._describe_availability_zones(context, **kwargs)

    def _describe_availability_zones(self, context, **kwargs):
        ctxt = context.elevated()
        enabled_services = db.service_get_all(ctxt, False)
        disabled_services = db.service_get_all(ctxt, True)
        available_zones = []
        for zone in [service.availability_zone for service
                     in enabled_services]:
            if not zone in available_zones:
                available_zones.append(zone)
        not_available_zones = []
        for zone in [service.availability_zone for service in disabled_services
                     if not service['availability_zone'] in available_zones]:
            if not zone in not_available_zones:
                not_available_zones.append(zone)
        result = []
        for zone in available_zones:
            result.append({'zoneName': zone,
                           'zoneState': "available"})
        for zone in not_available_zones:
            result.append({'zoneName': zone,
                           'zoneState': "not available"})
        return {'availabilityZoneInfo': result}

    def _describe_availability_zones_verbose(self, context, **kwargs):
        rv = {'availabilityZoneInfo': [{'zoneName': 'nova',
                                        'zoneState': 'available'}]}

        services = db.service_get_all(context, False)
        hosts = []
        for host in [service['host'] for service in services]:
            if not host in hosts:
                hosts.append(host)
        for host in hosts:
            rv['availabilityZoneInfo'].append({'zoneName': '|- %s' % host,
                                               'zoneState': ''})
            hsvcs = [service for service in services
                     if service['host'] == host]
            for svc in hsvcs:
                alive = utils.service_is_up(svc)
                art = (alive and ":-)") or "XXX"
                active = 'enabled'
                if svc['disabled']:
                    active = 'disabled'
                rv['availabilityZoneInfo'].append({
                        'zoneName': '| |- %s' % svc['binary'],
                        'zoneState': '%s %s %s' % (active, art,
                                                   svc['updated_at'])})
        return rv

    def describe_regions(self, context, region_name=None, **kwargs):
        if FLAGS.region_list:
            regions = []
            for region in FLAGS.region_list:
                name, _sep, host = region.partition('=')
                endpoint = '%s://%s:%s%s' % (FLAGS.ec2_scheme,
                                             host,
                                             FLAGS.ec2_port,
                                             FLAGS.ec2_path)
                regions.append({'regionName': name,
                                'regionEndpoint': endpoint})
        else:
            regions = [{'regionName': 'nova',
                        'regionEndpoint': '%s://%s:%s%s' % (FLAGS.ec2_scheme,
                                                            FLAGS.ec2_host,
                                                            FLAGS.ec2_port,
                                                            FLAGS.ec2_path)}]
        return {'regionInfo': regions}

    def describe_snapshots(self,
                           context,
                           snapshot_id=None,
                           owner=None,
                           restorable_by=None,
                           **kwargs):
        if snapshot_id:
            snapshots = []
            for ec2_id in snapshot_id:
                internal_id = ec2utils.ec2_snap_id_to_uuid(ec2_id)
                snapshot = self.volume_api.get_snapshot(
                    context,
                    snapshot_id=internal_id)
                snapshots.append(snapshot)
        else:
            snapshots = self.volume_api.get_all_snapshots(context)
        snapshots = [self._format_snapshot(context, s) for s in snapshots]
        return {'snapshotSet': snapshots}

    def _format_snapshot(self, context, snapshot):
        s = {}
        s['snapshotId'] = ec2utils.id_to_ec2_snap_id(snapshot['id'])
        s['volumeId'] = ec2utils.id_to_ec2_vol_id(snapshot['volume_id'])
        s['status'] = snapshot['status']
        s['startTime'] = snapshot['created_at']
        s['progress'] = snapshot['progress']
        s['ownerId'] = snapshot['project_id']
        s['volumeSize'] = snapshot['volume_size']
        s['description'] = snapshot['display_description']
        return s

    def create_snapshot(self, context, volume_id, **kwargs):
        validate_ec2_id(volume_id)
        LOG.audit(_("Create snapshot of volume %s"), volume_id,
                  context=context)
        volume_id = ec2utils.ec2_vol_id_to_uuid(volume_id)
        volume = self.volume_api.get(context, volume_id)
        snapshot = self.volume_api.create_snapshot(
                context,
                volume,
                None,
                kwargs.get('description'))
        return self._format_snapshot(context, snapshot)

    def delete_snapshot(self, context, snapshot_id, **kwargs):
        snapshot_id = ec2utils.ec2_snap_id_to_uuid(snapshot_id)
        snapshot = self.volume_api.get_snapshot(context, snapshot_id)
        self.volume_api.delete_snapshot(context, snapshot)
        return True

    def describe_key_pairs(self, context, key_name=None, **kwargs):
        key_pairs = self.keypair_api.get_key_pairs(context, context.user_id)
        if not key_name is None:
            key_pairs = [x for x in key_pairs if x['name'] in key_name]

        result = []
        for key_pair in key_pairs:
            # filter out the vpn keys
            suffix = FLAGS.vpn_key_suffix
            if context.is_admin or not key_pair['name'].endswith(suffix):
                result.append({
                    'keyName': key_pair['name'],
                    'keyFingerprint': key_pair['fingerprint'],
                })

        return {'keySet': result}

    def create_key_pair(self, context, key_name, **kwargs):
        LOG.audit(_("Create key pair %s"), key_name, context=context)

        try:
            keypair = self.keypair_api.create_key_pair(context,
                                                       context.user_id,
                                                       key_name)
        except exception.KeypairLimitExceeded:
            msg = _("Quota exceeded, too many key pairs.")
            raise exception.EC2APIError(msg)
        except exception.InvalidKeypair:
            msg = _("Keypair data is invalid")
            raise exception.EC2APIError(msg)
        except exception.KeyPairExists:
            msg = _("Key pair '%s' already exists.") % key_name
            raise exception.KeyPairExists(msg)
        return {'keyName': key_name,
                'keyFingerprint': keypair['fingerprint'],
                'keyMaterial': keypair['private_key']}
        # TODO(vish): when context is no longer an object, pass it here

    def import_key_pair(self, context, key_name, public_key_material,
                        **kwargs):
        LOG.audit(_("Import key %s"), key_name, context=context)

        public_key = base64.b64decode(public_key_material)

        try:
            keypair = self.keypair_api.import_key_pair(context,
                                                       context.user_id,
                                                       key_name,
                                                       public_key)
        except exception.KeypairLimitExceeded:
            msg = _("Quota exceeded, too many key pairs.")
            raise exception.EC2APIError(msg)
        except exception.InvalidKeypair:
            msg = _("Keypair data is invalid")
            raise exception.EC2APIError(msg)
        except exception.KeyPairExists:
            msg = _("Key pair '%s' already exists.") % key_name
            raise exception.EC2APIError(msg)

        return {'keyName': key_name,
                'keyFingerprint': keypair['fingerprint']}

    def delete_key_pair(self, context, key_name, **kwargs):
        LOG.audit(_("Delete key pair %s"), key_name, context=context)
        try:
            self.keypair_api.delete_key_pair(context, context.user_id,
                                             key_name)
        except exception.NotFound:
            # aws returns true even if the key doesn't exist
            pass
        return True

    def describe_security_groups(self, context, group_name=None, group_id=None,
                                 **kwargs):
        self.compute_api.ensure_default_security_group(context)
        if group_name or group_id:
            groups = []
            if group_name:
                for name in group_name:
                    group = db.security_group_get_by_name(context,
                                                          context.project_id,
                                                          name)
                    groups.append(group)
            if group_id:
                for gid in group_id:
                    group = db.security_group_get(context, gid)
                    groups.append(group)
        elif context.is_admin:
            groups = db.security_group_get_all(context)
        else:
            groups = db.security_group_get_by_project(context,
                                                      context.project_id)
        groups = [self._format_security_group(context, g) for g in groups]

        return {'securityGroupInfo':
                list(sorted(groups,
                            key=lambda k: (k['ownerId'], k['groupName'])))}

    def _format_security_group(self, context, group):
        g = {}
        g['groupDescription'] = group.description
        g['groupName'] = group.name
        g['ownerId'] = group.project_id
        g['ipPermissions'] = []
        for rule in group.rules:
            r = {}
            r['groups'] = []
            r['ipRanges'] = []
            if rule.group_id:
                source_group = db.security_group_get(context, rule.group_id)
                r['groups'] += [{'groupName': source_group.name,
                                 'userId': source_group.project_id}]
                if rule.protocol:
                    r['ipProtocol'] = rule.protocol
                    r['fromPort'] = rule.from_port
                    r['toPort'] = rule.to_port
                    g['ipPermissions'] += [dict(r)]
                else:
                    for protocol, min_port, max_port in (('icmp', -1, -1),
                                                         ('tcp', 1, 65535),
                                                         ('udp', 1, 65535)):
                        r['ipProtocol'] = protocol
                        r['fromPort'] = min_port
                        r['toPort'] = max_port
                        g['ipPermissions'] += [dict(r)]
            else:
                r['ipProtocol'] = rule.protocol
                r['fromPort'] = rule.from_port
                r['toPort'] = rule.to_port
                r['ipRanges'] += [{'cidrIp': rule.cidr}]
                g['ipPermissions'] += [r]
        return g

    def _rule_args_to_dict(self, context, kwargs):
        rules = []
        if not 'groups' in kwargs and not 'ip_ranges' in kwargs:
            rule = self._rule_dict_last_step(context, **kwargs)
            if rule:
                rules.append(rule)
            return rules
        if 'ip_ranges' in kwargs:
            rules = self._cidr_args_split(kwargs)
        else:
            rules = [kwargs]
        finalset = []
        for rule in rules:
            if 'groups' in rule:
                groups_values = self._groups_args_split(rule)
                for groups_value in groups_values:
                    final = self._rule_dict_last_step(context, **groups_value)
                    finalset.append(final)
            else:
                final = self._rule_dict_last_step(context, **rule)
                finalset.append(final)
        return finalset

    def _cidr_args_split(self, kwargs):
        cidr_args_split = []
        cidrs = kwargs['ip_ranges']
        for key, cidr in cidrs.iteritems():
            mykwargs = kwargs.copy()
            del mykwargs['ip_ranges']
            mykwargs['cidr_ip'] = cidr['cidr_ip']
            cidr_args_split.append(mykwargs)
        return cidr_args_split

    def _groups_args_split(self, kwargs):
        groups_args_split = []
        groups = kwargs['groups']
        for key, group in groups.iteritems():
            mykwargs = kwargs.copy()
            del mykwargs['groups']
            if 'group_name' in group:
                mykwargs['source_security_group_name'] = group['group_name']
            if 'user_id' in group:
                mykwargs['source_security_group_owner_id'] = group['user_id']
            if 'group_id' in group:
                mykwargs['source_security_group_id'] = group['group_id']
            groups_args_split.append(mykwargs)
        return groups_args_split

    def _rule_dict_last_step(self, context, to_port=None, from_port=None,
                                  ip_protocol=None, cidr_ip=None, user_id=None,
                                  source_security_group_name=None,
                                  source_security_group_owner_id=None):

        values = {}

        if source_security_group_name:
            source_project_id = self._get_source_project_id(context,
                source_security_group_owner_id)

            source_security_group = db.security_group_get_by_name(
                    context.elevated(),
                    source_project_id,
                    source_security_group_name)
            notfound = exception.SecurityGroupNotFound
            if not source_security_group:
                raise notfound(security_group_id=source_security_group_name)
            values['group_id'] = source_security_group['id']
        elif cidr_ip:
            # If this fails, it throws an exception. This is what we want.
            cidr_ip = urllib.unquote(cidr_ip).decode()

            if not utils.is_valid_cidr(cidr_ip):
                # Raise exception for non-valid address
                raise exception.EC2APIError(_("Invalid CIDR"))

            values['cidr'] = cidr_ip
        else:
            values['cidr'] = '0.0.0.0/0'

        if source_security_group_name:
            # Open everything if an explicit port range or type/code are not
            # specified, but only if a source group was specified.
            ip_proto_upper = ip_protocol.upper() if ip_protocol else ''
            if (ip_proto_upper == 'ICMP' and
                from_port is None and to_port is None):
                from_port = -1
                to_port = -1
            elif (ip_proto_upper in ['TCP', 'UDP'] and from_port is None
                  and to_port is None):
                from_port = 1
                to_port = 65535

        if ip_protocol and from_port is not None and to_port is not None:

            ip_protocol = str(ip_protocol)
            try:
                # Verify integer conversions
                from_port = int(from_port)
                to_port = int(to_port)
            except ValueError:
                if ip_protocol.upper() == 'ICMP':
                    raise exception.InvalidInput(reason="Type and"
                         " Code must be integers for ICMP protocol type")
                else:
                    raise exception.InvalidInput(reason="To and From ports "
                          "must be integers")

            if ip_protocol.upper() not in ['TCP', 'UDP', 'ICMP']:
                raise exception.InvalidIpProtocol(protocol=ip_protocol)

            # Verify that from_port must always be less than
            # or equal to to_port
            if (ip_protocol.upper() in ['TCP', 'UDP'] and
                (from_port > to_port)):
                raise exception.InvalidPortRange(from_port=from_port,
                      to_port=to_port, msg="Former value cannot"
                                            " be greater than the later")

            # Verify valid TCP, UDP port ranges
            if (ip_protocol.upper() in ['TCP', 'UDP'] and
                (from_port < 1 or to_port > 65535)):
                raise exception.InvalidPortRange(from_port=from_port,
                      to_port=to_port, msg="Valid TCP ports should"
                                           " be between 1-65535")

            # Verify ICMP type and code
            if (ip_protocol.upper() == "ICMP" and
                (from_port < -1 or from_port > 255 or
                to_port < -1 or to_port > 255)):
                raise exception.InvalidPortRange(from_port=from_port,
                      to_port=to_port, msg="For ICMP, the"
                                           " type:code must be valid")

            values['protocol'] = ip_protocol
            values['from_port'] = from_port
            values['to_port'] = to_port
        else:
            # If cidr based filtering, protocol and ports are mandatory
            if 'cidr' in values:
                return None

        return values

    def _security_group_rule_exists(self, security_group, values):
        """Indicates whether the specified rule values are already
           defined in the given security group.
        """
        for rule in security_group.rules:
            is_duplicate = True
            keys = ('group_id', 'cidr', 'from_port', 'to_port', 'protocol')
            for key in keys:
                if rule.get(key) != values.get(key):
                    is_duplicate = False
                    break
            if is_duplicate:
                return rule['id']
        return False

    def revoke_security_group_ingress(self, context, group_name=None,
                                      group_id=None, **kwargs):
        if not group_name and not group_id:
            err = _("Not enough parameters, need group_name or group_id")
            raise exception.EC2APIError(err)
        self.compute_api.ensure_default_security_group(context)
        notfound = exception.SecurityGroupNotFound
        if group_name:
            security_group = db.security_group_get_by_name(context,
                                                           context.project_id,
                                                           group_name)
            if not security_group:
                raise notfound(security_group_id=group_name)
        if group_id:
            security_group = db.security_group_get(context, group_id)
            if not security_group:
                raise notfound(security_group_id=group_id)

        msg = _("Revoke security group ingress %s")
        LOG.audit(msg, security_group['name'], context=context)
        prevalues = []
        try:
            prevalues = kwargs['ip_permissions']
        except KeyError:
            prevalues.append(kwargs)
        rule_id = None
        rule_ids = []
        for values in prevalues:
            rulesvalues = self._rule_args_to_dict(context, values)
            if not rulesvalues:
                err = _("%s Not enough parameters to build a valid rule")
                raise exception.EC2APIError(err % rulesvalues)

            for values_for_rule in rulesvalues:
                values_for_rule['parent_group_id'] = security_group.id
                rule_id = self._security_group_rule_exists(security_group,
                                                           values_for_rule)
                if rule_id:
                    db.security_group_rule_destroy(context, rule_id)
                    rule_ids.append(rule_id)
        if rule_id:
            # NOTE(vish): we removed a rule, so refresh
            self.compute_api.trigger_security_group_rules_refresh(
                    context,
                    security_group_id=security_group['id'])
            self.sgh.trigger_security_group_rule_destroy_refresh(
                    context, rule_ids)
            return True
        raise exception.EC2APIError(_("No rule for the specified parameters."))

    # TODO(soren): This has only been tested with Boto as the client.
    #              Unfortunately, it seems Boto is using an old API
    #              for these operations, so support for newer API versions
    #              is sketchy.
    def authorize_security_group_ingress(self, context, group_name=None,
                                         group_id=None, **kwargs):
        if not group_name and not group_id:
            err = _("Not enough parameters, need group_name or group_id")
            raise exception.EC2APIError(err)
        self.compute_api.ensure_default_security_group(context)
        notfound = exception.SecurityGroupNotFound
        if group_name:
            security_group = db.security_group_get_by_name(context,
                                                           context.project_id,
                                                           group_name)
            if not security_group:
                raise notfound(security_group_id=group_name)
        if group_id:
            security_group = db.security_group_get(context, group_id)
            if not security_group:
                raise notfound(security_group_id=group_id)

        msg = _("Authorize security group ingress %s")
        LOG.audit(msg, security_group['name'], context=context)
        prevalues = []
        try:
            prevalues = kwargs['ip_permissions']
        except KeyError:
            prevalues.append(kwargs)
        postvalues = []
        for values in prevalues:
            rulesvalues = self._rule_args_to_dict(context, values)
            if not rulesvalues:
                err = _("%s Not enough parameters to build a valid rule")
                raise exception.EC2APIError(err % rulesvalues)
            for values_for_rule in rulesvalues:
                values_for_rule['parent_group_id'] = security_group.id
                if self._security_group_rule_exists(security_group,
                                                    values_for_rule):
                    err = _('%s - This rule already exists in group')
                    raise exception.EC2APIError(err % values_for_rule)
                postvalues.append(values_for_rule)

        allowed = quota.allowed_security_group_rules(context,
                                                   security_group['id'],
                                                   1)
        if allowed < 1:
            msg = _("Quota exceeded, too many security group rules.")
            raise exception.EC2APIError(msg)

        rule_ids = []
        for values_for_rule in postvalues:
            security_group_rule = db.security_group_rule_create(
                    context,
                    values_for_rule)
            rule_ids.append(security_group_rule['id'])

        if postvalues:
            self.compute_api.trigger_security_group_rules_refresh(
                    context,
                    security_group_id=security_group['id'])
            self.sgh.trigger_security_group_rule_create_refresh(
                    context, rule_ids)
            return True

        raise exception.EC2APIError(_("No rule for the specified parameters."))

    def _get_source_project_id(self, context, source_security_group_owner_id):
        if source_security_group_owner_id:
        # Parse user:project for source group.
            source_parts = source_security_group_owner_id.split(':')

            # If no project name specified, assume it's same as user name.
            # Since we're looking up by project name, the user name is not
            # used here.  It's only read for EC2 API compatibility.
            if len(source_parts) == 2:
                source_project_id = source_parts[1]
            else:
                source_project_id = source_parts[0]
        else:
            source_project_id = context.project_id

        return source_project_id

    def create_security_group(self, context, group_name, group_description):
        if not re.match('^[a-zA-Z0-9_\- ]+$', str(group_name)):
            # Some validation to ensure that values match API spec.
            # - Alphanumeric characters, spaces, dashes, and underscores.
            # TODO(Daviey): LP: #813685 extend beyond group_name checking, and
            #  probably create a param validator that can be used elsewhere.
            err = _("Value (%s) for parameter GroupName is invalid."
                    " Content limited to Alphanumeric characters, "
                    "spaces, dashes, and underscores.") % group_name
            # err not that of master ec2 implementation, as they fail to raise.
            raise exception.InvalidParameterValue(err=err)

        if len(str(group_name)) > 255:
            err = _("Value (%s) for parameter GroupName is invalid."
                    " Length exceeds maximum of 255.") % group_name
            raise exception.InvalidParameterValue(err=err)

        LOG.audit(_("Create Security Group %s"), group_name, context=context)
        self.compute_api.ensure_default_security_group(context)
        if db.security_group_exists(context, context.project_id, group_name):
            msg = _('group %s already exists')
            raise exception.EC2APIError(msg % group_name)

        if quota.allowed_security_groups(context, 1) < 1:
            msg = _("Quota exceeded, too many security groups.")
            raise exception.EC2APIError(msg)

        group = {'user_id': context.user_id,
                 'project_id': context.project_id,
                 'name': group_name,
                 'description': group_description}
        group_ref = db.security_group_create(context, group)

        self.sgh.trigger_security_group_create_refresh(context, group)

        return {'securityGroupSet': [self._format_security_group(context,
                                                                 group_ref)]}

    def delete_security_group(self, context, group_name=None, group_id=None,
                              **kwargs):
        if not group_name and not group_id:
            err = _("Not enough parameters, need group_name or group_id")
            raise exception.EC2APIError(err)
        notfound = exception.SecurityGroupNotFound
        if group_name:
            security_group = db.security_group_get_by_name(context,
                                                           context.project_id,
                                                           group_name)
            if not security_group:
                raise notfound(security_group_id=group_name)
        elif group_id:
            security_group = db.security_group_get(context, group_id)
            if not security_group:
                raise notfound(security_group_id=group_id)
        if db.security_group_in_use(context, security_group.id):
            raise exception.InvalidGroup(reason="In Use")
        LOG.audit(_("Delete security group %s"), group_name, context=context)
        db.security_group_destroy(context, security_group.id)

        self.sgh.trigger_security_group_destroy_refresh(context,
                                                        security_group.id)
        return True

    def get_console_output(self, context, instance_id, **kwargs):
        LOG.audit(_("Get console output for instance %s"), instance_id,
                  context=context)
        # instance_id may be passed in as a list of instances
        if isinstance(instance_id, list):
            ec2_id = instance_id[0]
        else:
            ec2_id = instance_id
        validate_ec2_id(ec2_id)
        instance_id = ec2utils.ec2_id_to_id(ec2_id)
        instance = self.compute_api.get(context, instance_id)
        output = self.compute_api.get_console_output(context, instance)
        now = utils.utcnow()
        return {"InstanceId": ec2_id,
                "Timestamp": now,
                "output": base64.b64encode(output)}

    def describe_volumes(self, context, volume_id=None, **kwargs):
        if volume_id:
            volumes = []
            for ec2_id in volume_id:
                validate_ec2_id(ec2_id)
                internal_id = ec2utils.ec2_vol_id_to_uuid(ec2_id)
                volume = self.volume_api.get(context, internal_id)
                volumes.append(volume)
        else:
            volumes = self.volume_api.get_all(context)
        volumes = [self._format_volume(context, v) for v in volumes]
        return {'volumeSet': volumes}

    def _format_volume(self, context, volume):
        instance_ec2_id = None
        instance_data = None
        if volume.get('instance', None):
            instance_id = volume['instance']['id']
            instance_ec2_id = ec2utils.id_to_ec2_id(instance_id)
            instance_data = '%s[%s]' % (instance_ec2_id,
                                        volume['instance']['host'])
        v = {}
        v['volumeId'] = ec2utils.id_to_ec2_vol_id(volume['id'])
        v['status'] = volume['status']
        v['size'] = volume['size']
        v['availabilityZone'] = volume['availability_zone']
        v['createTime'] = volume['created_at']
        if context.is_admin:
            v['status'] = '%s (%s, %s, %s, %s)' % (
                volume['status'],
                volume['project_id'],
                volume['host'],
                instance_data,
                volume['mountpoint'])
        if volume['attach_status'] == 'attached':
            v['attachmentSet'] = [{'attachTime': volume['attach_time'],
                                   'deleteOnTermination': False,
                                   'device': volume['mountpoint'],
                                   'instanceId': instance_ec2_id,
                                   'status': 'attached',
                                   'volumeId': v['volumeId']}]
        else:
            v['attachmentSet'] = [{}]
        if volume.get('snapshot_id') is not None:
            v['snapshotId'] = ec2utils.id_to_ec2_snap_id(volume['snapshot_id'])
        else:
            v['snapshotId'] = None

        return v

    def create_volume(self, context, **kwargs):
        size = kwargs.get('size')
        if kwargs.get('snapshot_id') is not None:
            snapshot_id = ec2utils.ec2_snap_id_to_uuid(kwargs['snapshot_id'])
            snapshot = self.volume_api.get_snapshot(context, snapshot_id)
            LOG.audit(_("Create volume from snapshot %s"), snapshot_id,
                      context=context)
        else:
            snapshot = None
            LOG.audit(_("Create volume of %s GB"), size, context=context)

        availability_zone = kwargs.get('availability_zone', None)

        volume = self.volume_api.create(context,
                                        size,
                                        None,
                                        None,
                                        snapshot,
                                        availability_zone=availability_zone)
        # TODO(vish): Instance should be None at db layer instead of
        #             trying to lazy load, but for now we turn it into
        #             a dict to avoid an error.
        return self._format_volume(context, dict(volume))

    def delete_volume(self, context, volume_id, **kwargs):
        validate_ec2_id(volume_id)
        volume_id = ec2utils.ec2_vol_id_to_uuid(volume_id)

        try:
            volume = self.volume_api.get(context, volume_id)
            self.volume_api.delete(context, volume)
        except exception.InvalidVolume:
            raise exception.EC2APIError(_('Delete Failed'))

        return True

    def attach_volume(self, context, volume_id, instance_id, device, **kwargs):
        validate_ec2_id(instance_id)
        validate_ec2_id(volume_id)
        volume_id = ec2utils.ec2_vol_id_to_uuid(volume_id)
        instance_id = ec2utils.ec2_id_to_id(instance_id)
        instance = self.compute_api.get(context, instance_id)
        msg = _("Attach volume %(volume_id)s to instance %(instance_id)s"
                " at %(device)s") % locals()
        LOG.audit(msg, context=context)

        try:
            self.compute_api.attach_volume(context, instance,
                                           volume_id, device)
        except exception.InvalidVolume:
            raise exception.EC2APIError(_('Attach Failed.'))

        volume = self.volume_api.get(context, volume_id)
        return {'attachTime': volume['attach_time'],
                'device': volume['mountpoint'],
                'instanceId': ec2utils.id_to_ec2_id(instance_id),
                'requestId': context.request_id,
                'status': volume['attach_status'],
                'volumeId': ec2utils.id_to_ec2_vol_id(volume_id)}

    def detach_volume(self, context, volume_id, **kwargs):
        validate_ec2_id(volume_id)
        volume_id = ec2utils.ec2_vol_id_to_uuid(volume_id)
        LOG.audit(_("Detach volume %s"), volume_id, context=context)
        volume = self.volume_api.get(context, volume_id)

        try:
            instance = self.compute_api.detach_volume(context,
                                                      volume_id=volume_id)
        except exception.InvalidVolume:
            raise exception.EC2APIError(_('Detach Volume Failed.'))

        return {'attachTime': volume['attach_time'],
                'device': volume['mountpoint'],
                'instanceId': ec2utils.id_to_ec2_id(instance['id']),
                'requestId': context.request_id,
                'status': volume['attach_status'],
                'volumeId': ec2utils.id_to_ec2_vol_id(volume_id)}

    def _format_kernel_id(self, context, instance_ref, result, key):
        kernel_uuid = instance_ref['kernel_id']
        if kernel_uuid is None or kernel_uuid == '':
            return
        result[key] = ec2utils.glance_id_to_ec2_id(context, kernel_uuid, 'aki')

    def _format_ramdisk_id(self, context, instance_ref, result, key):
        ramdisk_uuid = instance_ref['ramdisk_id']
        if ramdisk_uuid is None or ramdisk_uuid == '':
            return
        result[key] = ec2utils.glance_id_to_ec2_id(context, ramdisk_uuid,
                                                   'ari')

    def describe_instance_attribute(self, context, instance_id, attribute,
                                    **kwargs):
        def _unsupported_attribute(instance, result):
            raise exception.EC2APIError(_('attribute not supported: %s') %
                                     attribute)

        def _format_attr_block_device_mapping(instance, result):
            tmp = {}
            self._format_instance_root_device_name(instance, tmp)
            self._format_instance_bdm(context, instance['uuid'],
                                      tmp['rootDeviceName'], result)

        def _format_attr_disable_api_termination(instance, result):
            result['disableApiTermination'] = instance['disable_terminate']

        def _format_attr_group_set(instance, result):
            CloudController._format_group_set(instance, result)

        def _format_attr_instance_initiated_shutdown_behavior(instance,
                                                               result):
            if instance['shutdown_terminate']:
                result['instanceInitiatedShutdownBehavior'] = 'terminate'
            else:
                result['instanceInitiatedShutdownBehavior'] = 'stop'

        def _format_attr_instance_type(instance, result):
            self._format_instance_type(instance, result)

        def _format_attr_kernel(instance, result):
            self._format_kernel_id(context, instance, result, 'kernel')

        def _format_attr_ramdisk(instance, result):
            self._format_ramdisk_id(context, instance, result, 'ramdisk')

        def _format_attr_root_device_name(instance, result):
            self._format_instance_root_device_name(instance, result)

        def _format_attr_source_dest_check(instance, result):
            _unsupported_attribute(instance, result)

        def _format_attr_user_data(instance, result):
            result['userData'] = base64.b64decode(instance['user_data'])

        attribute_formatter = {
            'blockDeviceMapping': _format_attr_block_device_mapping,
            'disableApiTermination': _format_attr_disable_api_termination,
            'groupSet': _format_attr_group_set,
            'instanceInitiatedShutdownBehavior':
            _format_attr_instance_initiated_shutdown_behavior,
            'instanceType': _format_attr_instance_type,
            'kernel': _format_attr_kernel,
            'ramdisk': _format_attr_ramdisk,
            'rootDeviceName': _format_attr_root_device_name,
            'sourceDestCheck': _format_attr_source_dest_check,
            'userData': _format_attr_user_data,
            }

        fn = attribute_formatter.get(attribute)
        if fn is None:
            raise exception.EC2APIError(
                _('attribute not supported: %s') % attribute)

        ec2_instance_id = instance_id
        validate_ec2_id(instance_id)
        instance_id = ec2utils.ec2_id_to_id(ec2_instance_id)
        instance = self.compute_api.get(context, instance_id)
        result = {'instance_id': ec2_instance_id}
        fn(instance, result)
        return result

    def describe_instances(self, context, **kwargs):
        # Optional DescribeInstances argument
        instance_id = kwargs.get('instance_id', None)
        return self._format_describe_instances(context,
                instance_id=instance_id)

    def describe_instances_v6(self, context, **kwargs):
        # Optional DescribeInstancesV6 argument
        instance_id = kwargs.get('instance_id', None)
        return self._format_describe_instances(context,
                instance_id=instance_id, use_v6=True)

    def _format_describe_instances(self, context, **kwargs):
        return {'reservationSet': self._format_instances(context, **kwargs)}

    def _format_run_instances(self, context, reservation_id):
        i = self._format_instances(context, reservation_id=reservation_id)
        assert len(i) == 1
        return i[0]

    def _format_terminate_instances(self, context, instance_id,
                                    previous_states):
        instances_set = []
        for (ec2_id, previous_state) in zip(instance_id, previous_states):
            i = {}
            i['instanceId'] = ec2_id
            i['previousState'] = _state_description(previous_state['vm_state'],
                                        previous_state['shutdown_terminate'])
            try:
                internal_id = ec2utils.ec2_id_to_id(ec2_id)
                instance = self.compute_api.get(context, internal_id)
                i['shutdownState'] = _state_description(instance['vm_state'],
                                            instance['shutdown_terminate'])
            except exception.NotFound:
                i['shutdownState'] = _state_description(vm_states.DELETED,
                                                        True)
            instances_set.append(i)
        return {'instancesSet': instances_set}

    def _format_instance_bdm(self, context, instance_uuid, root_device_name,
                             result):
        """Format InstanceBlockDeviceMappingResponseItemType"""
        root_device_type = 'instance-store'
        mapping = []
        for bdm in db.block_device_mapping_get_all_by_instance(context,
                                                               instance_uuid):
            volume_id = bdm['volume_id']
            if (volume_id is None or bdm['no_device']):
                continue

            if (bdm['device_name'] == root_device_name and
                (bdm['snapshot_id'] or bdm['volume_id'])):
                assert not bdm['virtual_name']
                root_device_type = 'ebs'

            vol = self.volume_api.get(context, volume_id)
            LOG.debug(_("vol = %s\n"), vol)
            # TODO(yamahata): volume attach time
            ebs = {'volumeId': volume_id,
                   'deleteOnTermination': bdm['delete_on_termination'],
                   'attachTime': vol['attach_time'] or '-',
                   'status': vol['status'], }
            res = {'deviceName': bdm['device_name'],
                   'ebs': ebs, }
            mapping.append(res)

        if mapping:
            result['blockDeviceMapping'] = mapping
        result['rootDeviceType'] = root_device_type

    @staticmethod
    def _format_instance_root_device_name(instance, result):
        result['rootDeviceName'] = (instance.get('root_device_name') or
                                    block_device.DEFAULT_ROOT_DEV_NAME)

    @staticmethod
    def _format_instance_type(instance, result):
        if instance['instance_type']:
            result['instanceType'] = instance['instance_type'].get('name')
        else:
            result['instanceType'] = None

    @staticmethod
    def _format_group_set(instance, result):
        security_group_names = []
        if instance.get('security_groups'):
            for security_group in instance['security_groups']:
                security_group_names.append(security_group['name'])
        result['groupSet'] = utils.convert_to_list_dict(
            security_group_names, 'groupId')

    def _format_instances(self, context, instance_id=None, use_v6=False,
            **search_opts):
        # TODO(termie): this method is poorly named as its name does not imply
        #               that it will be making a variety of database calls
        #               rather than simply formatting a bunch of instances that
        #               were handed to it
        reservations = {}
        # NOTE(vish): instance_id is an optional list of ids to filter by
        if instance_id:
            instances = []
            for ec2_id in instance_id:
                internal_id = ec2utils.ec2_id_to_id(ec2_id)
                try:
                    instance = self.compute_api.get(context, internal_id)
                except exception.NotFound:
                    continue
                instances.append(instance)
        else:
            try:
                # always filter out deleted instances
                search_opts['deleted'] = False
                instances = self.compute_api.get_all(context,
                                                     search_opts=search_opts,
                                                     sort_dir='asc')
            except exception.NotFound:
                instances = []
        for instance in instances:
            if not context.is_admin:
                if instance['image_ref'] == str(FLAGS.vpn_image_id):
                    continue
            i = {}
            instance_id = instance['id']
            ec2_id = ec2utils.id_to_ec2_id(instance_id)
            i['instanceId'] = ec2_id
            image_uuid = instance['image_ref']
            i['imageId'] = ec2utils.glance_id_to_ec2_id(context, image_uuid)
            self._format_kernel_id(context, instance, i, 'kernelId')
            self._format_ramdisk_id(context, instance, i, 'ramdiskId')
            i['instanceState'] = _state_description(
                instance['vm_state'], instance['shutdown_terminate'])

            fixed_ip = None
            floating_ip = None
            ip_info = ec2utils.get_ip_info_for_instance(context, instance)
            if ip_info['fixed_ips']:
                fixed_ip = ip_info['fixed_ips'][0]
            if ip_info['floating_ips']:
                floating_ip = ip_info['floating_ips'][0]
            if ip_info['fixed_ip6s']:
                i['dnsNameV6'] = ip_info['fixed_ip6s'][0]
            if FLAGS.ec2_private_dns_show_ip:
                i['privateDnsName'] = fixed_ip
            else:
                i['privateDnsName'] = instance['hostname']
            i['privateIpAddress'] = fixed_ip
            i['publicDnsName'] = floating_ip
            i['ipAddress'] = floating_ip or fixed_ip
            i['dnsName'] = i['publicDnsName'] or i['privateDnsName']
            i['keyName'] = instance['key_name']

            if context.is_admin:
                i['keyName'] = '%s (%s, %s)' % (i['keyName'],
                    instance['project_id'],
                    instance['host'])
            i['productCodesSet'] = utils.convert_to_list_dict([],
                                                              'product_codes')
            self._format_instance_type(instance, i)
            i['launchTime'] = instance['created_at']
            i['amiLaunchIndex'] = instance['launch_index']
            self._format_instance_root_device_name(instance, i)
            self._format_instance_bdm(context, instance['uuid'],
                                      i['rootDeviceName'], i)
            host = instance['host']
            services = db.service_get_all_by_host(context.elevated(), host)
            zone = ec2utils.get_availability_zone_by_host(services, host)
            i['placement'] = {'availabilityZone': zone}
            if instance['reservation_id'] not in reservations:
                r = {}
                r['reservationId'] = instance['reservation_id']
                r['ownerId'] = instance['project_id']
                self._format_group_set(instance, r)
                r['instancesSet'] = []
                reservations[instance['reservation_id']] = r
            reservations[instance['reservation_id']]['instancesSet'].append(i)

        return list(reservations.values())

    def describe_addresses(self, context, public_ip=None, **kwargs):
        if public_ip:
            floatings = []
            for address in public_ip:
                floating = self.network_api.get_floating_ip_by_address(context,
                                                                       address)
                floatings.append(floating)
        else:
            floatings = self.network_api.get_floating_ips_by_project(context)
        addresses = [self._format_address(context, f) for f in floatings]
        return {'addressesSet': addresses}

    def _format_address(self, context, floating_ip):
        ec2_id = None
        if floating_ip['fixed_ip_id']:
            fixed_id = floating_ip['fixed_ip_id']
            fixed = self.network_api.get_fixed_ip(context, fixed_id)
            if fixed['instance_id'] is not None:
                ec2_id = ec2utils.id_to_ec2_id(fixed['instance_id'])
        address = {'public_ip': floating_ip['address'],
                   'instance_id': ec2_id}
        if context.is_admin:
            details = "%s (%s)" % (address['instance_id'],
                                   floating_ip['project_id'])
            address['instance_id'] = details
        return address

    def allocate_address(self, context, **kwargs):
        LOG.audit(_("Allocate address"), context=context)
        public_ip = self.network_api.allocate_floating_ip(context)
        return {'publicIp': public_ip}

    def release_address(self, context, public_ip, **kwargs):
        LOG.audit(_("Release address %s"), public_ip, context=context)
        self.network_api.release_floating_ip(context, address=public_ip)
        return {'return': "true"}

    def associate_address(self, context, instance_id, public_ip, **kwargs):
        LOG.audit(_("Associate address %(public_ip)s to"
                " instance %(instance_id)s") % locals(), context=context)
        instance_id = ec2utils.ec2_id_to_id(instance_id)
        instance = self.compute_api.get(context, instance_id)
        self.compute_api.associate_floating_ip(context,
                                               instance,
                                               address=public_ip)
        return {'return': "true"}

    def disassociate_address(self, context, public_ip, **kwargs):
        LOG.audit(_("Disassociate address %s"), public_ip, context=context)
        self.network_api.disassociate_floating_ip(context, address=public_ip)
        return {'return': "true"}

    def run_instances(self, context, **kwargs):
        max_count = int(kwargs.get('max_count', 1))
        if kwargs.get('kernel_id'):
            kernel = self._get_image(context, kwargs['kernel_id'])
            kwargs['kernel_id'] = ec2utils.id_to_glance_id(context,
                                                           kernel['id'])
        if kwargs.get('ramdisk_id'):
            ramdisk = self._get_image(context, kwargs['ramdisk_id'])
            kwargs['ramdisk_id'] = ec2utils.id_to_glance_id(context,
                                                            ramdisk['id'])
        for bdm in kwargs.get('block_device_mapping', []):
            _parse_block_device_mapping(bdm)

        image = self._get_image(context, kwargs['image_id'])
        image_uuid = ec2utils.id_to_glance_id(context, image['id'])

        if image:
            image_state = self._get_image_state(image)
        else:
            raise exception.ImageNotFound(image_id=kwargs['image_id'])

        if image_state != 'available':
            raise exception.EC2APIError(_('Image must be available'))

        (instances, resv_id) = self.compute_api.create(context,
            instance_type=instance_types.get_instance_type_by_name(
                kwargs.get('instance_type', None)),
            image_href=image_uuid,
            min_count=int(kwargs.get('min_count', max_count)),
            max_count=max_count,
            kernel_id=kwargs.get('kernel_id'),
            ramdisk_id=kwargs.get('ramdisk_id'),
            key_name=kwargs.get('key_name'),
            user_data=kwargs.get('user_data'),
            security_group=kwargs.get('security_group'),
            availability_zone=kwargs.get('placement', {}).get(
                                  'availability_zone'),
            block_device_mapping=kwargs.get('block_device_mapping', {}))
        return self._format_run_instances(context, resv_id)

    def terminate_instances(self, context, instance_id, **kwargs):
        """Terminate each instance in instance_id, which is a list of ec2 ids.
        instance_id is a kwarg so its name cannot be modified."""
        LOG.debug(_("Going to start terminating instances"))
        previous_states = []
        for ec2_id in instance_id:
            validate_ec2_id(ec2_id)
            _instance_id = ec2utils.ec2_id_to_id(ec2_id)
            instance = self.compute_api.get(context, _instance_id)
            previous_states.append(instance)
            self.compute_api.delete(context, instance)
        return self._format_terminate_instances(context,
                                                instance_id,
                                                previous_states)

    def reboot_instances(self, context, instance_id, **kwargs):
        """instance_id is a list of instance ids"""
        LOG.audit(_("Reboot instance %r"), instance_id, context=context)
        for ec2_id in instance_id:
            validate_ec2_id(ec2_id)
            _instance_id = ec2utils.ec2_id_to_id(ec2_id)
            instance = self.compute_api.get(context, _instance_id)
            self.compute_api.reboot(context, instance, 'HARD')
        return True

    def stop_instances(self, context, instance_id, **kwargs):
        """Stop each instances in instance_id.
        Here instance_id is a list of instance ids"""
        LOG.debug(_("Going to stop instances"))
        for ec2_id in instance_id:
            validate_ec2_id(ec2_id)
            _instance_id = ec2utils.ec2_id_to_id(ec2_id)
            instance = self.compute_api.get(context, _instance_id)
            self.compute_api.stop(context, instance)
        return True

    def start_instances(self, context, instance_id, **kwargs):
        """Start each instances in instance_id.
        Here instance_id is a list of instance ids"""
        LOG.debug(_("Going to start instances"))
        for ec2_id in instance_id:
            validate_ec2_id(ec2_id)
            _instance_id = ec2utils.ec2_id_to_id(ec2_id)
            instance = self.compute_api.get(context, _instance_id)
            self.compute_api.start(context, instance)
        return True

    def _get_image(self, context, ec2_id):
        try:
            internal_id = ec2utils.ec2_id_to_id(ec2_id)
            image = self.image_service.show(context, internal_id)
        except (exception.InvalidEc2Id, exception.ImageNotFound):
            try:
                return self.image_service.show_by_name(context, ec2_id)
            except exception.NotFound:
                raise exception.ImageNotFound(image_id=ec2_id)
        image_type = ec2_id.split('-')[0]
        if ec2utils.image_type(image.get('container_format')) != image_type:
            raise exception.ImageNotFound(image_id=ec2_id)
        return image

    def _format_image(self, image):
        """Convert from format defined by GlanceImageService to S3 format."""
        i = {}
        image_type = ec2utils.image_type(image.get('container_format'))
        ec2_id = ec2utils.image_ec2_id(image.get('id'), image_type)
        name = image.get('name')
        i['imageId'] = ec2_id
        kernel_id = image['properties'].get('kernel_id')
        if kernel_id:
            i['kernelId'] = ec2utils.image_ec2_id(kernel_id, 'aki')
        ramdisk_id = image['properties'].get('ramdisk_id')
        if ramdisk_id:
            i['ramdiskId'] = ec2utils.image_ec2_id(ramdisk_id, 'ari')
        i['imageOwnerId'] = image.get('owner')

        img_loc = image['properties'].get('image_location')
        if img_loc:
            i['imageLocation'] = img_loc
        else:
            i['imageLocation'] = "%s (%s)" % (img_loc, name)

        i['name'] = name
        if not name and img_loc:
            # This should only occur for images registered with ec2 api
            # prior to that api populating the glance name
            i['name'] = img_loc

        i['imageState'] = self._get_image_state(image)
        i['description'] = image.get('description')
        display_mapping = {'aki': 'kernel',
                           'ari': 'ramdisk',
                           'ami': 'machine'}
        i['imageType'] = display_mapping.get(image_type)
        i['isPublic'] = not not image.get('is_public')
        i['architecture'] = image['properties'].get('architecture')

        properties = image['properties']
        root_device_name = block_device.properties_root_device_name(properties)
        root_device_type = 'instance-store'
        for bdm in properties.get('block_device_mapping', []):
            if (bdm.get('device_name') == root_device_name and
                ('snapshot_id' in bdm or 'volume_id' in bdm) and
                not bdm.get('no_device')):
                root_device_type = 'ebs'
        i['rootDeviceName'] = (root_device_name or
                               block_device.DEFAULT_ROOT_DEV_NAME)
        i['rootDeviceType'] = root_device_type

        _format_mappings(properties, i)

        return i

    def describe_images(self, context, image_id=None, **kwargs):
        # NOTE: image_id is a list!
        if image_id:
            images = []
            for ec2_id in image_id:
                try:
                    image = self._get_image(context, ec2_id)
                except exception.NotFound:
                    raise exception.ImageNotFound(image_id=ec2_id)
                images.append(image)
        else:
            images = self.image_service.detail(context)
        images = [self._format_image(i) for i in images]
        return {'imagesSet': images}

    def deregister_image(self, context, image_id, **kwargs):
        LOG.audit(_("De-registering image %s"), image_id, context=context)
        image = self._get_image(context, image_id)
        internal_id = image['id']
        self.image_service.delete(context, internal_id)
        return {'imageId': image_id}

    def _register_image(self, context, metadata):
        image = self.image_service.create(context, metadata)
        image_type = ec2utils.image_type(image.get('container_format'))
        image_id = ec2utils.image_ec2_id(image['id'], image_type)
        return image_id

    def register_image(self, context, image_location=None, **kwargs):
        if image_location is None and kwargs.get('name'):
            image_location = kwargs['name']
        if image_location is None:
            raise exception.EC2APIError(_('imageLocation is required'))

        metadata = {'properties': {'image_location': image_location}}

        if kwargs.get('name'):
            metadata['name'] = kwargs['name']
        else:
            metadata['name'] = image_location

        if 'root_device_name' in kwargs:
            metadata['properties']['root_device_name'] = kwargs.get(
                                                         'root_device_name')

        mappings = [_parse_block_device_mapping(bdm) for bdm in
                    kwargs.get('block_device_mapping', [])]
        if mappings:
            metadata['properties']['block_device_mapping'] = mappings

        image_id = self._register_image(context, metadata)
        msg = _("Registered image %(image_location)s with"
                " id %(image_id)s") % locals()
        LOG.audit(msg, context=context)
        return {'imageId': image_id}

    def describe_image_attribute(self, context, image_id, attribute, **kwargs):
        def _block_device_mapping_attribute(image, result):
            _format_mappings(image['properties'], result)

        def _launch_permission_attribute(image, result):
            result['launchPermission'] = []
            if image['is_public']:
                result['launchPermission'].append({'group': 'all'})

        def _root_device_name_attribute(image, result):
            _prop_root_dev_name = block_device.properties_root_device_name
            result['rootDeviceName'] = _prop_root_dev_name(image['properties'])
            if result['rootDeviceName'] is None:
                result['rootDeviceName'] = block_device.DEFAULT_ROOT_DEV_NAME

        supported_attributes = {
            'blockDeviceMapping': _block_device_mapping_attribute,
            'launchPermission': _launch_permission_attribute,
            'rootDeviceName': _root_device_name_attribute,
            }

        fn = supported_attributes.get(attribute)
        if fn is None:
            raise exception.EC2APIError(_('attribute not supported: %s')
                                     % attribute)
        try:
            image = self._get_image(context, image_id)
        except exception.NotFound:
            raise exception.ImageNotFound(image_id=image_id)

        result = {'imageId': image_id}
        fn(image, result)
        return result

    def modify_image_attribute(self, context, image_id, attribute,
                               operation_type, **kwargs):
        # TODO(devcamcar): Support users and groups other than 'all'.
        if attribute != 'launchPermission':
            raise exception.EC2APIError(_('attribute not supported: %s')
                                     % attribute)
        if not 'user_group' in kwargs:
            raise exception.EC2APIError(_('user or group not specified'))
        if len(kwargs['user_group']) != 1 and kwargs['user_group'][0] != 'all':
            raise exception.EC2APIError(_('only group "all" is supported'))
        if not operation_type in ['add', 'remove']:
            msg = _('operation_type must be add or remove')
            raise exception.EC2APIError(msg)
        LOG.audit(_("Updating image %s publicity"), image_id, context=context)

        try:
            image = self._get_image(context, image_id)
        except exception.NotFound:
            raise exception.ImageNotFound(image_id=image_id)
        internal_id = image['id']
        del(image['id'])

        image['is_public'] = (operation_type == 'add')
        try:
            return self.image_service.update(context, internal_id, image)
        except exception.ImageNotAuthorized:
            msg = _('Not allowed to modify attributes for image %s')
            raise exception.EC2APIError(msg % image_id)

    def update_image(self, context, image_id, **kwargs):
        internal_id = ec2utils.ec2_id_to_id(image_id)
        result = self.image_service.update(context, internal_id, dict(kwargs))
        return result

    # TODO(yamahata): race condition
    # At the moment there is no way to prevent others from
    # manipulating instances/volumes/snapshots.
    # As other code doesn't take it into consideration, here we don't
    # care of it for now. Ostrich algorithm
    def create_image(self, context, instance_id, **kwargs):
        # NOTE(yamahata): name/description are ignored by register_image(),
        #                 do so here
        no_reboot = kwargs.get('no_reboot', False)
        validate_ec2_id(instance_id)
        ec2_instance_id = instance_id
        instance_id = ec2utils.ec2_id_to_id(ec2_instance_id)
        instance = self.compute_api.get(context, instance_id)

        # stop the instance if necessary
        restart_instance = False
        if not no_reboot:
            vm_state = instance['vm_state']

            # if the instance is in subtle state, refuse to proceed.
            if vm_state not in (vm_states.ACTIVE, vm_states.SHUTOFF,
                                vm_states.STOPPED):
                raise exception.InstanceNotRunning(instance_id=ec2_instance_id)

            if vm_state in (vm_states.ACTIVE, vm_states.SHUTOFF):
                restart_instance = True
                self.compute_api.stop(context, instance)

            # wait instance for really stopped
            start_time = time.time()
            while vm_state != vm_states.STOPPED:
                time.sleep(1)
                instance = self.compute_api.get(context, instance_id)
                vm_state = instance['vm_state']
                # NOTE(yamahata): timeout and error. 1 hour for now for safety.
                #                 Is it too short/long?
                #                 Or is there any better way?
                timeout = 1 * 60 * 60
                if time.time() > start_time + timeout:
                    raise exception.EC2APIError(
                        _('Couldn\'t stop instance with in %d sec') % timeout)

        src_image = self._get_image(context, instance['image_ref'])
        properties = src_image['properties']
        if instance['root_device_name']:
            properties['root_device_name'] = instance['root_device_name']

        mapping = []
        bdms = db.block_device_mapping_get_all_by_instance(context,
                                                           instance_id)
        for bdm in bdms:
            if bdm.no_device:
                continue
            m = {}
            for attr in ('device_name', 'snapshot_id', 'volume_id',
                         'volume_size', 'delete_on_termination', 'no_device',
                         'virtual_name'):
                val = getattr(bdm, attr)
                if val is not None:
                    m[attr] = val

            volume_id = m.get('volume_id')
            if m.get('snapshot_id') and volume_id:
                # create snapshot based on volume_id
                volume = self.volume_api.get(context, volume_id)
                # NOTE(yamahata): Should we wait for snapshot creation?
                #                 Linux LVM snapshot creation completes in
                #                 short time, it doesn't matter for now.
                snapshot = self.volume_api.create_snapshot_force(
                        context, volume, volume['display_name'],
                        volume['display_description'])
                m['snapshot_id'] = snapshot['id']
                del m['volume_id']

            if m:
                mapping.append(m)

        for m in _properties_get_mappings(properties):
            virtual_name = m['virtual']
            if virtual_name in ('ami', 'root'):
                continue

            assert block_device.is_swap_or_ephemeral(virtual_name)
            device_name = m['device']
            if device_name in [b['device_name'] for b in mapping
                               if not b.get('no_device', False)]:
                continue

            # NOTE(yamahata): swap and ephemeral devices are specified in
            #                 AMI, but disabled for this instance by user.
            #                 So disable those device by no_device.
            mapping.append({'device_name': device_name, 'no_device': True})

        if mapping:
            properties['block_device_mapping'] = mapping

        for attr in ('status', 'location', 'id'):
            src_image.pop(attr, None)

        image_id = self._register_image(context, src_image)

        if restart_instance:
            self.compute_api.start(context, instance_id=instance_id)

        return {'imageId': image_id}