Source code for watcher.common.nova_helper
# -*- encoding: utf-8 -*-
# Copyright (c) 2015 b<>com
#
# Authors: Jean-Emile DARTOIS <jean-emile.dartois@b-com.com>
#
# 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.
#
import random
import time
from oslo_log import log
import cinderclient.exceptions as ciexceptions
import glanceclient.exc as glexceptions
import novaclient.exceptions as nvexceptions
from watcher.common import clients
from watcher.common import exception
from watcher.common import utils
LOG = log.getLogger(__name__)
[docs]class NovaHelper(object):
def __init__(self, osc=None):
""":param osc: an OpenStackClients instance"""
self.osc = osc if osc else clients.OpenStackClients()
self.neutron = self.osc.neutron()
self.cinder = self.osc.cinder()
self.nova = self.osc.nova()
self.glance = self.osc.glance()
[docs] def get_compute_node_by_id(self, node_id):
"""Get compute node by ID (*not* UUID)"""
# We need to pass an object with an 'id' attribute to make it work
return self.nova.hypervisors.get(utils.Struct(id=node_id))
[docs] def get_compute_node_by_hostname(self, node_hostname):
"""Get compute node by ID (*not* UUID)"""
# We need to pass an object with an 'id' attribute to make it work
try:
compute_nodes = self.nova.hypervisors.search(node_hostname)
if len(compute_nodes) != 1:
raise exception.ComputeNodeNotFound(name=node_hostname)
return self.get_compute_node_by_id(compute_nodes[0].id)
except Exception as exc:
LOG.exception(exc)
raise exception.ComputeNodeNotFound(name=node_hostname)
[docs] def get_instance_list(self):
return self.nova.servers.list(search_opts={'all_tenants': True})
[docs] def get_availability_zone_list(self):
return self.nova.availability_zones.list(detailed=True)
[docs] def wait_for_volume_status(self, volume, status, timeout=60,
poll_interval=1):
"""Wait until volume reaches given status.
:param volume: volume resource
:param status: expected status of volume
:param timeout: timeout in seconds
:param poll_interval: poll interval in seconds
"""
start_time = time.time()
while time.time() - start_time < timeout:
volume = self.cinder.volumes.get(volume.id)
if volume.status == status:
break
time.sleep(poll_interval)
else:
raise Exception("Volume %s did not reach status %s after %d s"
% (volume.id, status, timeout))
return volume.status == status
[docs] def watcher_non_live_migrate_instance(self, instance_id, dest_hostname,
keep_original_image_name=True):
"""This method migrates a given instance
using an image of this instance and creating a new instance
from this image. It saves some configuration information
about the original instance : security group, list of networks,
list of attached volumes, floating IP, ...
in order to apply the same settings to the new instance.
At the end of the process the original instance is deleted.
It returns True if the migration was successful,
False otherwise.
:param instance_id: the unique id of the instance to migrate.
:param keep_original_image_name: flag indicating whether the
image name from which the original instance was built must be
used as the name of the intermediate image used for migration.
If this flag is False, a temporary image name is built
"""
new_image_name = ""
LOG.debug(
"Trying a non-live migrate of instance '%s' "
"using a temporary image ..." % instance_id)
# Looking for the instance to migrate
instance = self.find_instance(instance_id)
if not instance:
LOG.debug("Instance %s not found !" % instance_id)
return False
else:
host_name = getattr(instance, "OS-EXT-SRV-ATTR:host")
LOG.debug(
"Instance %s found on host '%s'." % (instance_id, host_name))
if not keep_original_image_name:
# randrange gives you an integral value
irand = random.randint(0, 1000)
# Building the temporary image name
# which will be used for the migration
new_image_name = "tmp-migrate-%s-%s" % (instance_id, irand)
else:
# Get the image name of the current instance.
# We'll use the same name for the new instance.
imagedict = getattr(instance, "image")
image_id = imagedict["id"]
image = self.glance.images.get(image_id)
new_image_name = getattr(image, "name")
instance_name = getattr(instance, "name")
flavordict = getattr(instance, "flavor")
# a_dict = dict([flavorstr.strip('{}').split(":"),])
flavor_id = flavordict["id"]
flavor = self.nova.flavors.get(flavor_id)
flavor_name = getattr(flavor, "name")
keypair_name = getattr(instance, "key_name")
addresses = getattr(instance, "addresses")
floating_ip = ""
network_names_list = []
for network_name, network_conf_obj in addresses.items():
LOG.debug(
"Extracting network configuration for network '%s'" %
network_name)
network_names_list.append(network_name)
for net_conf_item in network_conf_obj:
if net_conf_item['OS-EXT-IPS:type'] == "floating":
floating_ip = net_conf_item['addr']
break
sec_groups_list = getattr(instance, "security_groups")
sec_groups = []
for sec_group_dict in sec_groups_list:
sec_groups.append(sec_group_dict['name'])
# Stopping the old instance properly so
# that no new data is sent to it and to its attached volumes
stopped_ok = self.stop_instance(instance_id)
if not stopped_ok:
LOG.debug("Could not stop instance: %s" % instance_id)
return False
# Building the temporary image which will be used
# to re-build the same instance on another target host
image_uuid = self.create_image_from_instance(instance_id,
new_image_name)
if not image_uuid:
LOG.debug(
"Could not build temporary image of instance: %s" %
instance_id)
return False
#
# We need to get the list of attached volumes and detach
# them from the instance in order to attache them later
# to the new instance
#
blocks = []
# Looks like this :
# os-extended-volumes:volumes_attached |
# [{u'id': u'c5c3245f-dd59-4d4f-8d3a-89d80135859a'}]
attached_volumes = getattr(instance,
"os-extended-volumes:volumes_attached")
for attached_volume in attached_volumes:
volume_id = attached_volume['id']
try:
volume = self.cinder.volumes.get(volume_id)
attachments_list = getattr(volume, "attachments")
device_name = attachments_list[0]['device']
# When a volume is attached to an instance
# it contains the following property :
# attachments = [{u'device': u'/dev/vdb',
# u'server_id': u'742cc508-a2f2-4769-a794-bcdad777e814',
# u'id': u'f6d62785-04b8-400d-9626-88640610f65e',
# u'host_name': None, u'volume_id':
# u'f6d62785-04b8-400d-9626-88640610f65e'}]
# boot_index indicates a number
# designating the boot order of the device.
# Use -1 for the boot volume,
# choose 0 for an attached volume.
block_device_mapping_v2_item = {"device_name": device_name,
"source_type": "volume",
"destination_type":
"volume",
"uuid": volume_id,
"boot_index": "0"}
blocks.append(
block_device_mapping_v2_item)
LOG.debug("Detaching volume %s from instance: %s" % (
volume_id, instance_id))
# volume.detach()
self.nova.volumes.delete_server_volume(instance_id,
volume_id)
if not self.wait_for_volume_status(volume, "available", 5,
10):
LOG.debug(
"Could not detach volume %s from instance: %s" % (
volume_id, instance_id))
return False
except ciexceptions.NotFound:
LOG.debug("Volume '%s' not found " % image_id)
return False
# We create the new instance from
# the intermediate image of the original instance
new_instance = self. \
create_instance(dest_hostname,
instance_name,
image_uuid,
flavor_name,
sec_groups,
network_names_list=network_names_list,
keypair_name=keypair_name,
create_new_floating_ip=False,
block_device_mapping_v2=blocks)
if not new_instance:
LOG.debug(
"Could not create new instance "
"for non-live migration of instance %s" % instance_id)
return False
try:
LOG.debug("Detaching floating ip '%s' from instance %s" % (
floating_ip, instance_id))
# We detach the floating ip from the current instance
instance.remove_floating_ip(floating_ip)
LOG.debug(
"Attaching floating ip '%s' to the new instance %s" % (
floating_ip, new_instance.id))
# We attach the same floating ip to the new instance
new_instance.add_floating_ip(floating_ip)
except Exception as e:
LOG.debug(e)
new_host_name = getattr(new_instance, "OS-EXT-SRV-ATTR:host")
# Deleting the old instance (because no more useful)
delete_ok = self.delete_instance(instance_id)
if not delete_ok:
LOG.debug("Could not delete instance: %s" % instance_id)
return False
LOG.debug(
"Instance %s has been successfully migrated "
"to new host '%s' and its new id is %s." % (
instance_id, new_host_name, new_instance.id))
return True
[docs] def resize_instance(self, instance_id, flavor, retry=120):
"""This method resizes given instance with specified flavor.
This method uses the Nova built-in resize()
action to do a resize of a given instance.
It returns True if the resize was successful,
False otherwise.
:param instance_id: the unique id of the instance to resize.
:param flavor: the name or ID of the flavor to resize to.
"""
LOG.debug("Trying a resize of instance %s to flavor '%s'" % (
instance_id, flavor))
# Looking for the instance to resize
instance = self.find_instance(instance_id)
flavor_id = None
try:
flavor_id = self.nova.flavors.get(flavor)
except nvexceptions.NotFound:
flavor_id = [f.id for f in self.nova.flavors.list() if
f.name == flavor][0]
except nvexceptions.ClientException as e:
LOG.debug("Nova client exception occurred while resizing "
"instance %s. Exception: %s", instance_id, e)
if not flavor_id:
LOG.debug("Flavor not found: %s" % flavor)
return False
if not instance:
LOG.debug("Instance not found: %s" % instance_id)
return False
instance_status = getattr(instance, 'OS-EXT-STS:vm_state')
LOG.debug(
"Instance %s is in '%s' status." % (instance_id,
instance_status))
instance.resize(flavor=flavor_id)
while getattr(instance,
'OS-EXT-STS:vm_state') != 'resized' \
and retry:
instance = self.nova.servers.get(instance.id)
LOG.debug(
'Waiting the resize of {0} to {1}'.format(
instance, flavor_id))
time.sleep(1)
retry -= 1
instance_status = getattr(instance, 'status')
if instance_status != 'VERIFY_RESIZE':
return False
instance.confirm_resize()
LOG.debug("Resizing succeeded : instance %s is now on flavor "
"'%s'.", instance_id, flavor_id)
return True
[docs] def live_migrate_instance(self, instance_id, dest_hostname,
block_migration=False, retry=120):
"""This method does a live migration of a given instance
This method uses the Nova built-in live_migrate()
action to do a live migration of a given instance.
It returns True if the migration was successful,
False otherwise.
:param instance_id: the unique id of the instance to migrate.
:param dest_hostname: the name of the destination compute node.
:param block_migration: No shared storage is required.
"""
LOG.debug("Trying a live migrate of instance %s to host '%s'" % (
instance_id, dest_hostname))
# Looking for the instance to migrate
instance = self.find_instance(instance_id)
if not instance:
LOG.debug("Instance not found: %s" % instance_id)
return False
else:
host_name = getattr(instance, 'OS-EXT-SRV-ATTR:host')
LOG.debug(
"Instance %s found on host '%s'." % (instance_id, host_name))
instance.live_migrate(host=dest_hostname,
block_migration=block_migration,
disk_over_commit=True)
while getattr(instance,
'OS-EXT-SRV-ATTR:host') != dest_hostname \
and retry:
instance = self.nova.servers.get(instance.id)
LOG.debug(
'Waiting the migration of {0} to {1}'.format(
instance,
getattr(instance,
'OS-EXT-SRV-ATTR:host')))
time.sleep(1)
retry -= 1
host_name = getattr(instance, 'OS-EXT-SRV-ATTR:host')
if host_name != dest_hostname:
return False
LOG.debug(
"Live migration succeeded : "
"instance %s is now on host '%s'." % (
instance_id, host_name))
return True
[docs] def enable_service_nova_compute(self, hostname):
if self.nova.services.enable(host=hostname,
binary='nova-compute'). \
status == 'enabled':
return True
else:
return False
[docs] def disable_service_nova_compute(self, hostname):
if self.nova.services.disable(host=hostname,
binary='nova-compute'). \
status == 'disabled':
return True
else:
return False
[docs] def set_host_offline(self, hostname):
# See API on http://developer.openstack.org/api-ref-compute-v2.1.html
# especially the PUT request
# regarding this resource : /v2.1/os-hosts/{host_name}
#
# The following body should be sent :
# {
# "host": {
# "host": "65c5d5b7e3bd44308e67fc50f362aee6",
# "maintenance_mode": "off_maintenance",
# "status": "enabled"
# }
# }
# Voir ici
# https://github.com/openstack/nova/
# blob/master/nova/virt/xenapi/host.py
# set_host_enabled(self, enabled):
# Sets the compute host's ability to accept new instances.
# host_maintenance_mode(self, host, mode):
# Start/Stop host maintenance window.
# On start, it triggers guest instances evacuation.
host = self.nova.hosts.get(hostname)
if not host:
LOG.debug("host not found: %s" % hostname)
return False
else:
host[0].update(
{"maintenance_mode": "disable", "status": "disable"})
return True
[docs] def create_image_from_instance(self, instance_id, image_name,
metadata={"reason": "instance_migrate"}):
"""This method creates a new image from a given instance.
It waits for this image to be in 'active' state before returning.
It returns the unique UUID of the created image if successful,
None otherwise.
:param instance_id: the uniqueid of
the instance to backup as an image.
:param image_name: the name of the image to create.
:param metadata: a dictionary containing the list of
key-value pairs to associate to the image as metadata.
"""
LOG.debug(
"Trying to create an image from instance %s ..." % instance_id)
# Looking for the instance
instance = self.find_instance(instance_id)
if not instance:
LOG.debug("Instance not found: %s" % instance_id)
return None
else:
host_name = getattr(instance, 'OS-EXT-SRV-ATTR:host')
LOG.debug(
"Instance %s found on host '%s'." % (instance_id, host_name))
# We need to wait for an appropriate status
# of the instance before we can build an image from it
if self.wait_for_instance_status(instance, ('ACTIVE', 'SHUTOFF'),
5,
10):
image_uuid = self.nova.servers.create_image(instance_id,
image_name,
metadata)
image = self.glance.images.get(image_uuid)
if not image:
return None
# Waiting for the new image to be officially in ACTIVE state
# in order to make sure it can be used
status = image.status
retry = 10
while status != 'active' and status != 'error' and retry:
time.sleep(5)
retry -= 1
# Retrieve the instance again so the status field updates
image = self.glance.images.get(image_uuid)
if not image:
break
status = image.status
LOG.debug("Current image status: %s" % status)
if not image:
LOG.debug("Image not found: %s" % image_uuid)
else:
LOG.debug(
"Image %s successfully created for instance %s" % (
image_uuid, instance_id))
return image_uuid
return None
[docs] def delete_instance(self, instance_id):
"""This method deletes a given instance.
:param instance_id: the unique id of the instance to delete.
"""
LOG.debug("Trying to remove instance %s ..." % instance_id)
instance = self.find_instance(instance_id)
if not instance:
LOG.debug("Instance not found: %s" % instance_id)
return False
else:
self.nova.servers.delete(instance_id)
LOG.debug("Instance %s removed." % instance_id)
return True
[docs] def stop_instance(self, instance_id):
"""This method stops a given instance.
:param instance_id: the unique id of the instance to stop.
"""
LOG.debug("Trying to stop instance %s ..." % instance_id)
instance = self.find_instance(instance_id)
if not instance:
LOG.debug("Instance not found: %s" % instance_id)
return False
elif getattr(instance, 'OS-EXT-STS:vm_state') == "stopped":
LOG.debug("Instance has been stopped: %s" % instance_id)
return True
else:
self.nova.servers.stop(instance_id)
if self.wait_for_instance_state(instance, "stopped", 8, 10):
LOG.debug("Instance %s stopped." % instance_id)
return True
else:
return False
[docs] def wait_for_instance_state(self, server, state, retry, sleep):
"""Waits for server to be in a specific state
The state can be one of the following :
active, stopped
:param server: server object.
:param state: for which state we are waiting for
:param retry: how many times to retry
:param sleep: seconds to sleep between the retries
"""
if not server:
return False
while getattr(server, 'OS-EXT-STS:vm_state') != state and retry:
time.sleep(sleep)
server = self.nova.servers.get(server)
retry -= 1
return getattr(server, 'OS-EXT-STS:vm_state') == state
[docs] def wait_for_instance_status(self, instance, status_list, retry, sleep):
"""Waits for instance to be in a specific status
The status can be one of the following
: BUILD, ACTIVE, ERROR, VERIFY_RESIZE, SHUTOFF
:param instance: instance object.
:param status_list: tuple containing the list of
status we are waiting for
:param retry: how many times to retry
:param sleep: seconds to sleep between the retries
"""
if not instance:
return False
while instance.status not in status_list and retry:
LOG.debug("Current instance status: %s" % instance.status)
time.sleep(sleep)
instance = self.nova.servers.get(instance.id)
retry -= 1
LOG.debug("Current instance status: %s" % instance.status)
return instance.status in status_list
[docs] def create_instance(self, node_id, inst_name="test", image_id=None,
flavor_name="m1.tiny",
sec_group_list=["default"],
network_names_list=["demo-net"], keypair_name="mykeys",
create_new_floating_ip=True,
block_device_mapping_v2=None):
"""This method creates a new instance
It also creates, if requested, a new floating IP and associates
it with the new instance
It returns the unique id of the created instance.
"""
LOG.debug(
"Trying to create new instance '%s' "
"from image '%s' with flavor '%s' ..." % (
inst_name, image_id, flavor_name))
try:
self.nova.keypairs.findall(name=keypair_name)
except nvexceptions.NotFound:
LOG.debug("Key pair '%s' not found " % keypair_name)
return
try:
image = self.glance.images.get(image_id)
except glexceptions.NotFound:
LOG.debug("Image '%s' not found " % image_id)
return
try:
flavor = self.nova.flavors.find(name=flavor_name)
except nvexceptions.NotFound:
LOG.debug("Flavor '%s' not found " % flavor_name)
return
# Make sure all security groups exist
for sec_group_name in sec_group_list:
try:
self.nova.security_groups.find(name=sec_group_name)
except nvexceptions.NotFound:
LOG.debug("Security group '%s' not found " % sec_group_name)
return
net_list = list()
for network_name in network_names_list:
nic_id = self.get_network_id_from_name(network_name)
if not nic_id:
LOG.debug("Network '%s' not found " % network_name)
return
net_obj = {"net-id": nic_id}
net_list.append(net_obj)
instance = self.nova.servers.create(
inst_name, image,
flavor=flavor,
key_name=keypair_name,
security_groups=sec_group_list,
nics=net_list,
block_device_mapping_v2=block_device_mapping_v2,
availability_zone="nova:%s" % node_id)
# Poll at 5 second intervals, until the status is no longer 'BUILD'
if instance:
if self.wait_for_instance_status(instance,
('ACTIVE', 'ERROR'), 5, 10):
instance = self.nova.servers.get(instance.id)
if create_new_floating_ip and instance.status == 'ACTIVE':
LOG.debug(
"Creating a new floating IP"
" for instance '%s'" % instance.id)
# Creating floating IP for the new instance
floating_ip = self.nova.floating_ips.create()
instance.add_floating_ip(floating_ip)
LOG.debug("Instance %s associated to Floating IP '%s'" % (
instance.id, floating_ip.ip))
return instance
[docs] def get_network_id_from_name(self, net_name="private"):
"""This method returns the unique id of the provided network name"""
networks = self.neutron.list_networks(name=net_name)
# LOG.debug(networks)
network_id = networks['networks'][0]['id']
return network_id
[docs] def get_instance_by_uuid(self, instance_uuid):
return [instance for instance in
self.nova.servers.list(search_opts={"all_tenants": True,
"uuid": instance_uuid})]
[docs] def get_instance_by_name(self, instance_name):
return [instance for instance in
self.nova.servers.list(search_opts={"all_tenants": True,
"name": instance_name})]
[docs] def get_instances_by_node(self, host):
return [instance for instance in
self.nova.servers.list(search_opts={"all_tenants": True})
if self.get_hostname(instance) == host]
[docs] def get_flavor_instance(self, instance, cache):
fid = instance.flavor['id']
if fid in cache:
flavor = cache.get(fid)
else:
try:
flavor = self.nova.flavors.get(fid)
except ciexceptions.NotFound:
flavor = None
cache[fid] = flavor
attr_defaults = [('name', 'unknown-id-%s' % fid),
('vcpus', 0), ('ram', 0), ('disk', 0),
('ephemeral', 0), ('extra_specs', {})]
for attr, default in attr_defaults:
if not flavor:
instance.flavor[attr] = default
continue
instance.flavor[attr] = getattr(flavor, attr, default)
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