X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=snaps%2Fopenstack%2Futils%2Fnova_utils.py;h=38460c50dacf48ac2f6ebb66ac8e88cb681322e8;hb=390d31e3a6eaa0968474d19d71ec804d0c6c071a;hp=db9a666f475e7c7efc06ad4ffa72780f264c495f;hpb=e05d0deffeeda87c43e746fc09cad2249f2adcc5;p=snaps.git diff --git a/snaps/openstack/utils/nova_utils.py b/snaps/openstack/utils/nova_utils.py index db9a666..38460c5 100644 --- a/snaps/openstack/utils/nova_utils.py +++ b/snaps/openstack/utils/nova_utils.py @@ -15,15 +15,19 @@ import logging +import enum import os +import time from cryptography.hazmat.backends import default_backend from cryptography.hazmat.primitives import serialization from cryptography.hazmat.primitives.asymmetric import rsa from novaclient.client import Client -from novaclient.exceptions import NotFound +from novaclient.exceptions import NotFound, ClientException +from snaps import file_utils from snaps.domain.flavor import Flavor from snaps.domain.keypair import Keypair +from snaps.domain.project import ComputeQuotas from snaps.domain.vm_inst import VmInst from snaps.openstack.utils import keystone_utils, glance_utils, neutron_utils @@ -31,114 +35,312 @@ __author__ = 'spisarski' logger = logging.getLogger('nova_utils') +POLL_INTERVAL = 3 + """ Utilities for basic OpenStack Nova API calls """ -def nova_client(os_creds): +def nova_client(os_creds, session=None): """ Instantiates and returns a client for communications with OpenStack's Nova server :param os_creds: The connection credentials to the OpenStack API + :param session: the keystone session object (optional) :return: the client object """ logger.debug('Retrieving Nova Client') + if not session: + session = keystone_utils.keystone_session(os_creds) + return Client(os_creds.compute_api_version, - session=keystone_utils.keystone_session(os_creds)) + session=session, + region_name=os_creds.region_name) -def create_server(nova, neutron, glance, instance_settings, image_settings, - keypair_settings=None): +def create_server(nova, keystone, neutron, glance, instance_config, + image_config, project_name, keypair_config=None): """ Creates a VM instance :param nova: the nova client (required) + :param keystone: the keystone client for retrieving projects (required) :param neutron: the neutron client for retrieving ports (required) :param glance: the glance client (required) - :param instance_settings: the VM instance settings object (required) - :param image_settings: the VM's image settings object (required) - :param keypair_settings: the VM's keypair settings object (optional) + :param instance_config: the VMInstConfig object (required) + :param image_config: the VM's ImageConfig object (required) + :param project_name: the associated project name (required) + :param keypair_config: the VM's KeypairConfig object (optional) :return: a snaps.domain.VmInst object """ ports = list() - for port_setting in instance_settings.port_settings: - ports.append(neutron_utils.get_port_by_name( - neutron, port_setting.name)) + for port_setting in instance_config.port_settings: + port = neutron_utils.get_port( + neutron, keystone, port_settings=port_setting, + project_name=project_name) + if port: + ports.append(port) + else: + raise Exception('Cannot find port named - ' + port_setting.name) nics = [] for port in ports: kv = dict() - kv['port-id'] = port['port']['id'] + kv['port-id'] = port.id nics.append(kv) - logger.info('Creating VM with name - ' + instance_settings.name) + logger.info('Creating VM with name - ' + instance_config.name) keypair_name = None - if keypair_settings: - keypair_name = keypair_settings.name + if keypair_config: + keypair_name = keypair_config.name - flavor = get_flavor_by_name(nova, instance_settings.flavor) + flavor = get_flavor_by_name(nova, instance_config.flavor) if not flavor: - raise Exception( - 'Flavor not found with name - %s', - instance_settings.flavor) + raise NovaException( + 'Flavor not found with name - %s', instance_config.flavor) - image = glance_utils.get_image(glance, image_settings.name) + image = glance_utils.get_image(glance, image_settings=image_config) if image: - args = {'name': instance_settings.name, + userdata = None + if instance_config.userdata: + if isinstance(instance_config.userdata, str): + userdata = instance_config.userdata + '\n' + elif (isinstance(instance_config.userdata, dict) and + 'script_file' in instance_config.userdata): + try: + userdata = file_utils.read_file( + instance_config.userdata['script_file']) + except Exception as e: + logger.warn('error reading userdata file %s - %s', + instance_config.userdata, e) + args = {'name': instance_config.name, 'flavor': flavor, 'image': image, 'nics': nics, 'key_name': keypair_name, 'security_groups': - instance_settings.security_group_names, - 'userdata': instance_settings.userdata, - 'availability_zone': - instance_settings.availability_zone} + instance_config.security_group_names, + 'userdata': userdata} + + if instance_config.availability_zone: + args['availability_zone'] = instance_config.availability_zone + server = nova.servers.create(**args) - return VmInst(name=server.name, inst_id=server.id, - networks=server.networks) + + return __map_os_server_obj_to_vm_inst( + neutron, keystone, server, project_name) else: - raise Exception( + raise NovaException( 'Cannot create instance, image cannot be located with name %s', - image_settings.name) + image_config.name) -def get_servers_by_name(nova, name): +def get_server(nova, neutron, keystone, vm_inst_settings=None, + server_name=None, project_id=None): """ - Returns a list of servers with a given name + Returns a VmInst object for the first server instance found. :param nova: the Nova client - :param name: the server name - :return: the list of servers - """ - out = list() - servers = nova.servers.list(search_opts={'name': name}) + :param neutron: the Neutron client + :param keystone: the Keystone client + :param vm_inst_settings: the VmInstanceConfig object from which to build + the query if not None + :param server_name: the server with this name to return if vm_inst_settings + is not None + :param project_id: the assocaited project ID + :return: a snaps.domain.VmInst object or None if not found + """ + search_opts = dict() + if vm_inst_settings: + search_opts['name'] = vm_inst_settings.name + elif server_name: + search_opts['name'] = server_name + + servers = nova.servers.list(search_opts=search_opts) for server in servers: - out.append(VmInst(name=server.name, inst_id=server.id, - networks=server.networks)) - return out + return __map_os_server_obj_to_vm_inst( + neutron, keystone, server, project_id) -def get_latest_server_os_object(nova, server): +def get_server_connection(nova, vm_inst_settings=None, server_name=None): + """ + Returns a VmInst object for the first server instance found. + :param nova: the Nova client + :param vm_inst_settings: the VmInstanceConfig object from which to build + the query if not None + :param server_name: the server with this name to return if vm_inst_settings + is not None + :return: a snaps.domain.VmInst object or None if not found + """ + search_opts = dict() + if vm_inst_settings: + search_opts['name'] = vm_inst_settings.name + elif server_name: + search_opts['name'] = server_name + + servers = nova.servers.list(search_opts=search_opts) + for server in servers: + return server.links[0] + + +def __map_os_server_obj_to_vm_inst(neutron, keystone, os_server, + project_name=None): + """ + Returns a VmInst object for an OpenStack Server object + :param neutron: the Neutron client + :param keystone: the Keystone client + :param os_server: the OpenStack server object + :param project_name: the associated project name + :return: an equivalent SNAPS-OO VmInst domain object + """ + sec_grp_names = list() + # VM must be active for 'security_groups' attr to be initialized + if hasattr(os_server, 'security_groups'): + for sec_group in os_server.security_groups: + if sec_group.get('name'): + sec_grp_names.append(sec_group.get('name')) + + out_ports = list() + if len(os_server.networks) > 0: + for net_name, ips in os_server.networks.items(): + network = neutron_utils.get_network( + neutron, keystone, network_name=net_name, + project_name=project_name) + ports = neutron_utils.get_ports(neutron, network, ips) + for port in ports: + out_ports.append(port) + + volumes = None + if hasattr(os_server, 'os-extended-volumes:volumes_attached'): + volumes = getattr(os_server, 'os-extended-volumes:volumes_attached') + + return VmInst( + name=os_server.name, inst_id=os_server.id, + image_id=os_server.image['id'], flavor_id=os_server.flavor['id'], + ports=out_ports, keypair_name=os_server.key_name, + sec_grp_names=sec_grp_names, volume_ids=volumes, + compute_host=os_server._info.get('OS-EXT-SRV-ATTR:host'), + availability_zone=os_server._info.get('OS-EXT-AZ:availability_zone')) + + +def __get_latest_server_os_object(nova, server): """ Returns a server with a given id :param nova: the Nova client :param server: the domain VmInst object :return: the list of servers or None if not found """ - return nova.servers.get(server.id) + return __get_latest_server_os_object_by_id(nova, server.id) + + +def __get_latest_server_os_object_by_id(nova, server_id): + """ + Returns a server with a given id + :param nova: the Nova client + :param server_id: the server's ID + :return: the list of servers or None if not found + """ + return nova.servers.get(server_id) + + +def get_server_status(nova, server): + """ + Returns the a VM instance's status from OpenStack + :param nova: the Nova client + :param server: the domain VmInst object + :return: the VM's string status or None if not founc + """ + server = __get_latest_server_os_object(nova, server) + if server: + return server.status + return None + + +def get_server_console_output(nova, server): + """ + Returns the console object for parsing VM activity + :param nova: the Nova client + :param server: the domain VmInst object + :return: the console output object or None if server object is not found + """ + server = __get_latest_server_os_object(nova, server) + if server: + return server.get_console_output() + return None -def get_latest_server_object(nova, server): +def get_latest_server_object(nova, neutron, keystone, server, project_name): """ Returns a server with a given id :param nova: the Nova client + :param neutron: the Neutron client + :param keystone: the Keystone client :param server: the old server object + :param project_name: the associated project name :return: the list of servers or None if not found """ - server = get_latest_server_os_object(nova, server) - return VmInst(name=server.name, inst_id=server.id, - networks=server.networks) + server = __get_latest_server_os_object(nova, server) + return __map_os_server_obj_to_vm_inst( + neutron, keystone, server, project_name) + + +def get_server_object_by_id(nova, neutron, keystone, server_id, + project_name=None): + """ + Returns a server with a given id + :param nova: the Nova client + :param neutron: the Neutron client + :param keystone: the Keystone client + :param server_id: the server's id + :param project_name: the associated project name + :return: an SNAPS-OO VmInst object or None if not found + """ + server = __get_latest_server_os_object_by_id(nova, server_id) + return __map_os_server_obj_to_vm_inst( + neutron, keystone, server, project_name) + + +def get_server_security_group_names(nova, server): + """ + Returns a server with a given id + :param nova: the Nova client + :param server: the old server object + :return: the list of security groups associated with a VM + """ + out = list() + os_vm_inst = __get_latest_server_os_object(nova, server) + for sec_grp_dict in os_vm_inst.security_groups: + out.append(sec_grp_dict['name']) + return out + + +def get_server_info(nova, server): + """ + Returns a dictionary of a VMs info as returned by OpenStack + :param nova: the Nova client + :param server: the old server object + :return: a dict of the info if VM exists else None + """ + vm = __get_latest_server_os_object(nova, server) + if vm: + return vm._info + return None + + +def reboot_server(nova, server, reboot_type=None): + """ + Returns a dictionary of a VMs info as returned by OpenStack + :param nova: the Nova client + :param server: the old server object + :param reboot_type: Acceptable values 'SOFT', 'HARD' + (api uses SOFT as the default) + :return: a dict of the info if VM exists else None + """ + vm = __get_latest_server_os_object(nova, server) + if vm: + vm.reboot(reboot_type=reboot_type.value) + else: + raise ServerNotFoundError('Cannot locate server') def create_keys(key_size=2048): @@ -168,7 +370,6 @@ def save_keys_to_files(keys=None, pub_file_path=None, priv_file_path=None): :param keys: the keys to save generated by cryptography :param pub_file_path: the path to the public keys :param priv_file_path: the path to the private keys - :return: None """ if keys: if pub_file_path: @@ -178,13 +379,19 @@ def save_keys_to_files(keys=None, pub_file_path=None, priv_file_path=None): if not os.path.isdir(pub_dir): os.mkdir(pub_dir) - public_handle = open(pub_expand_file, 'wb') - public_bytes = keys.public_key().public_bytes( - serialization.Encoding.OpenSSH, - serialization.PublicFormat.OpenSSH) - public_handle.write(public_bytes) - public_handle.close() - os.chmod(pub_expand_file, 0o400) + + public_handle = None + try: + public_handle = open(pub_expand_file, 'wb') + public_bytes = keys.public_key().public_bytes( + serialization.Encoding.OpenSSH, + serialization.PublicFormat.OpenSSH) + public_handle.write(public_bytes) + finally: + if public_handle: + public_handle.close() + + os.chmod(pub_expand_file, 0o600) logger.info("Saved public key to - " + pub_expand_file) if priv_file_path: # To support '~' @@ -192,14 +399,20 @@ def save_keys_to_files(keys=None, pub_file_path=None, priv_file_path=None): priv_dir = os.path.dirname(priv_expand_file) if not os.path.isdir(priv_dir): os.mkdir(priv_dir) - private_handle = open(priv_expand_file, 'wb') - private_handle.write( - keys.private_bytes( - encoding=serialization.Encoding.PEM, - format=serialization.PrivateFormat.TraditionalOpenSSL, - encryption_algorithm=serialization.NoEncryption())) - private_handle.close() - os.chmod(priv_expand_file, 0o400) + + private_handle = None + try: + private_handle = open(priv_expand_file, 'wb') + private_handle.write( + keys.private_bytes( + encoding=serialization.Encoding.PEM, + format=serialization.PrivateFormat.TraditionalOpenSSL, + encryption_algorithm=serialization.NoEncryption())) + finally: + if private_handle: + private_handle.close() + + os.chmod(priv_expand_file, 0o600) logger.info("Saved private key to - " + priv_expand_file) @@ -211,9 +424,14 @@ def upload_keypair_file(nova, name, file_path): :param file_path: the path to the public key file :return: the keypair object """ - with open(os.path.expanduser(file_path), 'rb') as fpubkey: - logger.info('Saving keypair to - ' + file_path) - return upload_keypair(nova, name, fpubkey.read()) + fpubkey = None + try: + with open(os.path.expanduser(file_path), 'rb') as fpubkey: + logger.info('Saving keypair to - ' + file_path) + return upload_keypair(nova, name, fpubkey.read()) + finally: + if fpubkey: + fpubkey.close() def upload_keypair(nova, name, key): @@ -226,7 +444,8 @@ def upload_keypair(nova, name, key): """ logger.info('Creating keypair with name - ' + name) os_kp = nova.keypairs.create(name=name, public_key=key.decode('utf-8')) - return Keypair(name=os_kp.name, id=os_kp.id, public_key=os_kp.public_key) + return Keypair(name=os_kp.name, kp_id=os_kp.id, + public_key=os_kp.public_key, fingerprint=os_kp.fingerprint) def keypair_exists(nova, keypair_obj): @@ -238,7 +457,8 @@ def keypair_exists(nova, keypair_obj): """ try: os_kp = nova.keypairs.get(keypair_obj) - return Keypair(name=os_kp.name, id=os_kp.id, public_key=os_kp.public_key) + return Keypair(name=os_kp.name, kp_id=os_kp.id, + public_key=os_kp.public_key) except: return None @@ -254,12 +474,24 @@ def get_keypair_by_name(nova, name): for keypair in keypairs: if keypair.name == name: - return Keypair(name=keypair.name, id=keypair.id, + return Keypair(name=keypair.name, kp_id=keypair.id, public_key=keypair.public_key) return None +def get_keypair_by_id(nova, kp_id): + """ + Returns a list of all available keypairs + :param nova: the Nova client + :param kp_id: the ID of the keypair to return + :return: the keypair object + """ + keypair = nova.keypairs.get(kp_id) + return Keypair(name=keypair.name, kp_id=keypair.id, + public_key=keypair.public_key) + + def delete_keypair(nova, key): """ Deletes a keypair object from OpenStack @@ -270,16 +502,17 @@ def delete_keypair(nova, key): nova.keypairs.delete(key.id) -def get_nova_availability_zones(nova): +def get_availability_zone_hosts(nova, zone_name='nova'): """ Returns the names of all nova active compute servers :param nova: the Nova client + :param zone_name: the Nova client :return: a list of compute server names """ out = list() zones = nova.availability_zones.list() for zone in zones: - if zone.zoneName == 'nova': + if zone.zoneName == zone_name and zone.hosts: for key, host in zone.hosts.items(): if host['nova-compute']['available']: out.append(zone.zoneName + ':' + key) @@ -287,6 +520,21 @@ def get_nova_availability_zones(nova): return out +def get_hypervisor_hosts(nova): + """ + Returns the host names of all nova nodes with active hypervisors + :param nova: the Nova client + :return: a list of hypervisor host names + """ + out = list() + hypervisors = nova.hypervisors.list() + for hypervisor in hypervisors: + if hypervisor.state == "up": + out.append(hypervisor.hypervisor_hostname) + + return out + + def delete_vm_instance(nova, vm_inst): """ Deletes a VM instance @@ -296,15 +544,15 @@ def delete_vm_instance(nova, vm_inst): nova.servers.delete(vm_inst.id) -def get_os_flavor(nova, flavor): +def __get_os_flavor(nova, flavor_id): """ Returns to OpenStack flavor object by name :param nova: the Nova client - :param flavor: the SNAPS flavor domain object + :param flavor_id: the flavor's ID value :return: the OpenStack Flavor object """ try: - return nova.flavors.get(flavor.id) + return nova.flavors.get(flavor_id) except NotFound: return None @@ -316,7 +564,7 @@ def get_flavor(nova, flavor): :param flavor: the SNAPS flavor domain object :return: the SNAPS Flavor domain object """ - os_flavor = get_os_flavor(nova, flavor) + os_flavor = __get_os_flavor(nova, flavor.id) if os_flavor: return Flavor( name=os_flavor.name, id=os_flavor.id, ram=os_flavor.ram, @@ -329,7 +577,23 @@ def get_flavor(nova, flavor): return None -def get_os_flavor_by_name(nova, name): +def get_flavor_by_id(nova, flavor_id): + """ + Returns to OpenStack flavor object by name + :param nova: the Nova client + :param flavor_id: the flavor ID value + :return: the SNAPS Flavor domain object + """ + os_flavor = __get_os_flavor(nova, flavor_id) + if os_flavor: + return Flavor( + name=os_flavor.name, id=os_flavor.id, ram=os_flavor.ram, + disk=os_flavor.disk, vcpus=os_flavor.vcpus, + ephemeral=os_flavor.ephemeral, swap=os_flavor.swap, + rxtx_factor=os_flavor.rxtx_factor, is_public=os_flavor.is_public) + + +def __get_os_flavor_by_name(nova, name): """ Returns to OpenStack flavor object by name :param nova: the Nova client @@ -349,7 +613,7 @@ def get_flavor_by_name(nova, name): :param name: the flavor name to return :return: the SNAPS flavor domain object or None if not exists """ - os_flavor = get_os_flavor_by_name(nova, name) + os_flavor = __get_os_flavor_by_name(nova, name) if os_flavor: return Flavor( name=os_flavor.name, id=os_flavor.id, ram=os_flavor.ram, @@ -394,11 +658,22 @@ def set_flavor_keys(nova, flavor, metadata): :param flavor: the SNAPS flavor domain object :param metadata: the metadata to set """ - os_flavor = get_os_flavor(nova, flavor) + os_flavor = __get_os_flavor(nova, flavor.id) if os_flavor: os_flavor.set_keys(metadata) +def get_flavor_keys(nova, flavor): + """ + Sets metadata on the flavor + :param nova: the Nova client + :param flavor: the SNAPS flavor domain object + """ + os_flavor = __get_os_flavor(nova, flavor.id) + if os_flavor: + return os_flavor.get_keys() + + def add_security_group(nova, vm, security_group_name): """ Adds a security group to an existing VM @@ -406,7 +681,18 @@ def add_security_group(nova, vm, security_group_name): :param vm: the OpenStack server object (VM) to alter :param security_group_name: the name of the security group to add """ - nova.servers.add_security_group(str(vm.id), security_group_name) + try: + nova.servers.add_security_group(str(vm.id), security_group_name) + except ClientException as e: + sec_grp_names = get_server_security_group_names(nova, vm) + if security_group_name in sec_grp_names: + logger.warn('Security group [%s] already added to VM [%s]', + security_group_name, vm.name) + return + + logger.error('Unexpected error while adding security group [%s] - %s', + security_group_name, e) + raise def remove_security_group(nova, vm, security_group): @@ -414,19 +700,131 @@ def remove_security_group(nova, vm, security_group): Removes a security group from an existing VM :param nova: the nova client :param vm: the OpenStack server object (VM) to alter - :param security_group: the OpenStack security group object to add + :param security_group: the SNAPS SecurityGroup domain object to add + """ + nova.servers.remove_security_group(str(vm.id), security_group.name) + + +def get_compute_quotas(nova, project_id): """ - nova.servers.remove_security_group( - str(vm.id), security_group['security_group']['name']) + Returns a list of all available keypairs + :param nova: the Nova client + :param project_id: the project's ID of the quotas to lookup + :return: an object of type ComputeQuotas or None if not found + """ + quotas = nova.quotas.get(tenant_id=project_id) + if quotas: + return ComputeQuotas(quotas) -def add_floating_ip_to_server(nova, vm, floating_ip, ip_addr): +def update_quotas(nova, project_id, compute_quotas): """ - Adds a floating IP to a server instance + Updates the compute quotas for a given project + :param nova: the Nova client + :param project_id: the project's ID that requires quota updates + :param compute_quotas: an object of type ComputeQuotas containing the + values to update + :return: + """ + update_values = dict() + update_values['metadata_items'] = compute_quotas.metadata_items + update_values['cores'] = compute_quotas.cores + update_values['instances'] = compute_quotas.instances + update_values['injected_files'] = compute_quotas.injected_files + update_values['injected_file_content_bytes'] = ( + compute_quotas.injected_file_content_bytes) + update_values['ram'] = compute_quotas.ram + update_values['fixed_ips'] = compute_quotas.fixed_ips + update_values['key_pairs'] = compute_quotas.key_pairs + + return nova.quotas.update(project_id, **update_values) + + +def attach_volume(nova, neutron, keystone, server, volume, project_name, + timeout=120): + """ + Attaches a volume to a server. When the timeout parameter is used, a VmInst + object with the proper volume updates is returned unless it has not been + updated in the allotted amount of time then an Exception will be raised. :param nova: the nova client - :param vm: VmInst domain object - :param floating_ip: FloatingIp domain object - :param ip_addr: the IP to which to bind the floating IP to + :param neutron: the neutron client + :param keystone: the neutron client + :param server: the VMInst domain object + :param volume: the Volume domain object + :param project_name: the associated project name + :param timeout: denotes the amount of time to block to determine if the + has been properly attached. + :return: updated VmInst object + """ + nova.volumes.create_server_volume(server.id, volume.id) + + start_time = time.time() + while time.time() < start_time + timeout: + vm = get_server_object_by_id( + nova, neutron, keystone, server.id, project_name) + for vol_dict in vm.volume_ids: + if volume.id == vol_dict['id']: + return vm + time.sleep(POLL_INTERVAL) + + raise NovaException( + 'Attach failed on volume - {} and server - {}'.format( + volume.id, server.id)) + + +def detach_volume(nova, neutron, keystone, server, volume, project_name, + timeout=120): + """ + Detaches a volume to a server. When the timeout parameter is used, a VmInst + object with the proper volume updates is returned unless it has not been + updated in the allotted amount of time then an Exception will be raised. + :param nova: the nova client + :param neutron: the neutron client + :param keystone: the keystone client + :param server: the VMInst domain object + :param volume: the Volume domain object + :param project_name: the associated project name + :param timeout: denotes the amount of time to block to determine if the + has been properly detached. + :return: updated VmInst object + """ + nova.volumes.delete_server_volume(server.id, volume.id) + + start_time = time.time() + while time.time() < start_time + timeout: + vm = get_server_object_by_id( + nova, neutron, keystone, server.id, project_name) + if len(vm.volume_ids) == 0: + return vm + else: + ids = list() + for vol_dict in vm.volume_ids: + ids.append(vol_dict['id']) + if volume.id not in ids: + return vm + time.sleep(POLL_INTERVAL) + + raise NovaException( + 'Detach failed on volume - {} server - {}'.format( + volume.id, server.id)) + + +class RebootType(enum.Enum): + """ + A rule's direction + """ + soft = 'SOFT' + hard = 'HARD' + + +class NovaException(Exception): + """ + Exception when calls to the Keystone client cannot be served properly + """ + + +class ServerNotFoundError(Exception): + """ + Exception when operations to a VM/Server is requested and the OpenStack + Server instance cannot be located """ - vm = get_latest_server_os_object(nova, vm) - vm.add_floating_ip(floating_ip.ip, ip_addr)