path: root/snaps/openstack/create_instance.py

# Copyright (c) 2016 Cable Television Laboratories, Inc. ("CableLabs")
#                    and others.  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.
import logging
import time

from neutronclient.common.exceptions import PortNotFoundClient
from novaclient.exceptions import NotFound

from snaps.openstack.utils import glance_utils
from snaps.openstack.utils import neutron_utils
from snaps.openstack.create_network import PortSettings
from snaps.provisioning import ansible_utils
from snaps.openstack.utils import nova_utils

__author__ = 'spisarski'

logger = logging.getLogger('create_instance')

POLL_INTERVAL = 3
STATUS_ACTIVE = 'ACTIVE'
STATUS_DELETED = 'DELETED'


class OpenStackVmInstance:
    """
    Class responsible for creating a VM instance in OpenStack
    """

    def __init__(self, os_creds, instance_settings, image_settings, keypair_settings=None):
        """
        Constructor
        :param os_creds: The connection credentials to the OpenStack API
        :param instance_settings: Contains the settings for this VM
        :param image_settings: The OpenStack image object settings
        :param keypair_settings: The keypair metadata (Optional)
        :raises Exception
        """
        self.__os_creds = os_creds

        self.__nova = nova_utils.nova_client(self.__os_creds)
        self.__neutron = neutron_utils.neutron_client(self.__os_creds)

        self.instance_settings = instance_settings
        self.image_settings = image_settings
        self.keypair_settings = keypair_settings

        # TODO - get rid of FIP list and only use the dict(). Need to fix populating this object when already exists
        self.__floating_ips = list()
        self.__floating_ip_dict = dict()

        # Instantiated in self.create()
        self.__ports = list()

        # Note: this object does not change after the VM becomes active
        self.__vm = None

    def create(self, cleanup=False, block=False):
        """
        Creates a VM instance
        :param cleanup: When true, only perform lookups for OpenStack objects.
        :param block: Thread will block until instance has either become active, error, or timeout waiting.
                      Additionally, when True, floating IPs will not be applied until VM is active.
        :return: The VM reference object
        """
        try:
            self.__ports = self.__setup_ports(self.instance_settings.port_settings, cleanup)
            self.__lookup_existing_vm_by_name()
            if not self.__vm and not cleanup:
                self.__create_vm(block)
            return self.__vm
        except Exception as e:
            logger.exception('Error occurred while setting up instance')
            self.clean()
            raise e

    def __lookup_existing_vm_by_name(self):
        """
        Populates the member variables 'self.vm' and 'self.floating_ips' if a VM with the same name already exists
        within the project
        """
        servers = nova_utils.get_servers_by_name(self.__nova, self.instance_settings.name)
        for server in servers:
            if server.name == self.instance_settings.name:
                self.__vm = server
                logger.info('Found existing machine with name - ' + self.instance_settings.name)
                fips = self.__nova.floating_ips.list()
                for fip in fips:
                    if fip.instance_id == server.id:
                        self.__floating_ips.append(fip)
                        # TODO - Determine a means to associate to the FIP configuration and add to FIP map

    def __create_vm(self, block=False):
        """
        Responsible for creating the VM instance
        :param block: Thread will block until instance has either become active, error, or timeout waiting.
                      Floating IPs will be assigned after active when block=True
        """
        nics = []
        for key, port in self.__ports:
            kv = dict()
            kv['port-id'] = port['port']['id']
            nics.append(kv)

        logger.info('Creating VM with name - ' + self.instance_settings.name)
        keypair_name = None
        if self.keypair_settings:
            keypair_name = self.keypair_settings.name

        flavor = nova_utils.get_flavor_by_name(self.__nova, self.instance_settings.flavor)
        if not flavor:
            raise Exception('Flavor not found with name - ' + self.instance_settings.flavor)

        image = glance_utils.get_image(self.__nova, glance_utils.glance_client(self.__os_creds),
                                       self.image_settings.name)
        if image:
            self.__vm = self.__nova.servers.create(
                name=self.instance_settings.name,
                flavor=flavor,
                image=image,
                nics=nics,
                key_name=keypair_name,
                security_groups=self.instance_settings.security_group_names,
                userdata=self.instance_settings.userdata,
                availability_zone=self.instance_settings.availability_zone)

        else:
            raise Exception('Cannot create instance, image cannot be located with name ' + self.image_settings.name)

        logger.info('Created instance with name - ' + self.instance_settings.name)

        if block:
            self.vm_active(block=True)

        # TODO - the call above should add security groups. The return object shows they exist but the association
        # had never been made by OpenStack. This call is here to ensure they have been added
        for sec_grp_name in self.instance_settings.security_group_names:
            nova_utils.add_security_group(self.__nova, self.__vm, sec_grp_name)

        self.__apply_floating_ips()

    def __apply_floating_ips(self):
        """
        Applies the configured floating IPs to the necessary ports
        """
        port_dict = dict()
        for key, port in self.__ports:
            port_dict[key] = port

        # Apply floating IPs
        for floating_ip_setting in self.instance_settings.floating_ip_settings:
            port = port_dict.get(floating_ip_setting.port_name)

            if not port:
                raise Exception('Cannot find port object with name - ' + floating_ip_setting.port_name)

            # Setup Floating IP only if there is a router with an external gateway
            ext_gateway = self.__ext_gateway_by_router(floating_ip_setting.router_name)
            if ext_gateway:
                subnet = neutron_utils.get_subnet_by_name(self.__neutron, floating_ip_setting.subnet_name)
                floating_ip = nova_utils.create_floating_ip(self.__nova, ext_gateway)
                self.__floating_ips.append(floating_ip)
                self.__floating_ip_dict[floating_ip_setting.name] = floating_ip

                logger.info('Created floating IP ' + floating_ip.ip + ' via router - ' +
                            floating_ip_setting.router_name)
                self.__add_floating_ip(floating_ip, port, subnet)
            else:
                raise Exception('Unable to add floating IP to port,' +
                                ' cannot locate router with an external gateway ')

    def __ext_gateway_by_router(self, router_name):
        """
        Returns network name for the external network attached to a router or None if not found
        :param router_name: The name of the router to lookup
        :return: the external network name or None
        """
        router = neutron_utils.get_router_by_name(self.__neutron, router_name)
        if router and router['router'].get('external_gateway_info'):
            network = neutron_utils.get_network_by_id(self.__neutron,
                                                      router['router']['external_gateway_info']['network_id'])
            if network:
                return network['network']['name']
        return None

    def clean(self):
        """
        Destroys the VM instance
        """

        # Cleanup floating IPs
        for floating_ip in self.__floating_ips:
            try:
                logger.info('Deleting Floating IP - ' + floating_ip.ip)
                nova_utils.delete_floating_ip(self.__nova, floating_ip)
            except Exception as e:
                logger.error('Error deleting Floating IP - ' + e.message)
        self.__floating_ips = list()
        self.__floating_ip_dict = dict()

        # Cleanup ports
        for name, port in self.__ports:
            logger.info('Deleting Port - ' + name)
            try:
                neutron_utils.delete_port(self.__neutron, port)
            except PortNotFoundClient as e:
                logger.warn('Unexpected error deleting port - ' + e.message)
                pass
        self.__ports = list()

        # Cleanup VM
        if self.__vm:
            try:
                logger.info('Deleting VM instance - ' + self.instance_settings.name)
                nova_utils.delete_vm_instance(self.__nova, self.__vm)
            except Exception as e:
                logger.error('Error deleting VM - ' + str(e))

            # Block until instance cannot be found or returns the status of DELETED
            logger.info('Checking deletion status')

            try:
                if self.vm_deleted(block=True):
                    logger.info('VM has been properly deleted VM with name - ' + self.instance_settings.name)
                    self.__vm = None
                else:
                    logger.error('VM not deleted within the timeout period of ' +
                                 str(self.instance_settings.vm_delete_timeout) + ' seconds')
            except Exception as e:
                logger.error('Unexpected error while checking VM instance status - ' + e.message)

    def __setup_ports(self, port_settings, cleanup):
        """
        Returns the previously configured ports or creates them if they do not exist
        :param port_settings: A list of PortSetting objects
        :param cleanup: When true, only perform lookups for OpenStack objects.
        :return: a list of OpenStack port tuples where the first member is the port name and the second is the port
                 object
        """
        ports = list()

        for port_setting in port_settings:
            # First check to see if network already has this port
            # TODO/FIXME - this could potentially cause problems if another port with the same name exists
            # VM has the same network/port name pair
            found = False

            # TODO/FIXME - should we not be iterating on ports for the specific network in question as unique port names
            # seem to only be important by network
            existing_ports = self.__neutron.list_ports()['ports']
            for existing_port in existing_ports:
                if existing_port['name'] == port_setting.name:
                    ports.append((port_setting.name, {'port': existing_port}))
                    found = True
                    break

            if not found and not cleanup:
                ports.append((port_setting.name, neutron_utils.create_port(self.__neutron, self.__os_creds,
                                                                           port_setting)))

        return ports

    def __add_floating_ip(self, floating_ip, port, subnet, timeout=30, poll_interval=POLL_INTERVAL):
        """
        Returns True when active else False
        TODO - Make timeout and poll_interval configurable...
        """
        ip = None

        if subnet:
            # Take IP of subnet if there is one configured on which to place the floating IP
            for fixed_ip in port['port']['fixed_ips']:
                if fixed_ip['subnet_id'] == subnet['subnet']['id']:
                    ip = fixed_ip['ip_address']
                    break
        else:
            # Simply take the first
            ip = port['port']['fixed_ips'][0]['ip_address']

        if ip:
            count = timeout / poll_interval
            while count > 0:
                logger.debug('Attempting to add floating IP to instance')
                try:
                    self.__vm.add_floating_ip(floating_ip, ip)
                    logger.info('Added floating IP ' + floating_ip.ip + ' to port IP - ' + ip +
                                ' on instance - ' + self.instance_settings.name)
                    return
                except Exception as e:
                    logger.debug('Retry adding floating IP to instance. Last attempt failed with - ' + e.message)
                    time.sleep(poll_interval)
                    count -= 1
                    pass
        else:
            raise Exception('Unable find IP address on which to place the floating IP')

        logger.error('Timeout attempting to add the floating IP to instance.')
        raise Exception('Timeout while attempting add floating IP to instance')

    def get_os_creds(self):
        """
        Returns the OpenStack credentials used to create these objects
        :return: the credentials
        """
        return self.__os_creds

    def get_vm_inst(self):
        """
        Returns the latest version of this server object from OpenStack
        :return: Server object
        """
        return nova_utils.get_latest_server_object(self.__nova, self.__vm)

    def get_port_ip(self, port_name, subnet_name=None):
        """
        Returns the first IP for the port corresponding with the port_name parameter when subnet_name is None
        else returns the IP address that corresponds to the subnet_name parameter
        :param port_name: the name of the port from which to return the IP
        :param subnet_name: the name of the subnet attached to this IP
        :return: the IP or None if not found
        """
        port = self.get_port_by_name(port_name)
        if port:
            port_dict = port['port']
            if subnet_name:
                subnet = neutron_utils.get_subnet_by_name(self.__neutron, subnet_name)
                if not subnet:
                    logger.warn('Cannot retrieve port IP as subnet could not be located with name - ' + subnet_name)
                    return None
                for fixed_ip in port_dict['fixed_ips']:
                    if fixed_ip['subnet_id'] == subnet['subnet']['id']:
                        return fixed_ip['ip_address']
            else:
                fixed_ips = port_dict['fixed_ips']
                if fixed_ips and len(fixed_ips) > 0:
                    return fixed_ips[0]['ip_address']
        return None

    def get_port_mac(self, port_name):
        """
        Returns the first IP for the port corresponding with the port_name parameter
        TODO - Add in the subnet as an additional parameter as a port may have multiple fixed_ips
        :param port_name: the name of the port from which to return the IP
        :return: the IP or None if not found
        """
        port = self.get_port_by_name(port_name)
        if port:
            port_dict = port['port']
            return port_dict['mac_address']
        return None

    def get_port_by_name(self, port_name):
        """
        Retrieves the OpenStack port object by its given name
        :param port_name: the name of the port
        :return: the OpenStack port object or None if not exists
        """
        for key, port in self.__ports:
            if key == port_name:
                return port
        logger.warn('Cannot find port with name - ' + port_name)
        return None

    def config_nics(self):
        """
        Responsible for configuring NICs on RPM systems where the instance has more than one configured port
        :return: None
        """
        if len(self.__ports) > 1 and len(self.__floating_ips) > 0:
            if self.vm_active(block=True) and self.vm_ssh_active(block=True):
                for key, port in self.__ports:
                    port_index = self.__ports.index((key, port))
                    if port_index > 0:
                        nic_name = 'eth' + repr(port_index)
                        self.__config_nic(nic_name, port, self.__get_first_provisioning_floating_ip().ip)
                        logger.info('Configured NIC - ' + nic_name + ' on VM - ' + self.instance_settings.name)

    def __get_first_provisioning_floating_ip(self):
        """
        Returns the first floating IP tagged with the Floating IP name if exists else the first one found
        :return:
        """
        for floating_ip_setting in self.instance_settings.floating_ip_settings:
            if floating_ip_setting.provisioning:
                fip = self.__floating_ip_dict.get(floating_ip_setting.name)
                if fip:
                    return fip
                elif len(self.__floating_ips) > 0:
                    return self.__floating_ips[0]

    def __config_nic(self, nic_name, port, floating_ip):
        """
        Although ports/NICs can contain multiple IPs, this code currently only supports the first.

        Your CWD at this point must be the <repo dir>/python directory.
        TODO - fix this restriction.

        :param nic_name: Name of the interface
        :param port: The port information containing the expected IP values.
        :param floating_ip: The floating IP on which to apply the playbook.
        """
        ip = port['port']['fixed_ips'][0]['ip_address']
        variables = {
            'floating_ip': floating_ip,
            'nic_name': nic_name,
            'nic_ip': ip
        }

        if self.image_settings.nic_config_pb_loc and self.keypair_settings:
            ansible_utils.apply_playbook(self.image_settings.nic_config_pb_loc,
                                         [floating_ip], self.get_image_user(), self.keypair_settings.private_filepath,
                                         variables, self.__os_creds.proxy_settings)
        else:
            logger.warn('VM ' + self.instance_settings.name + ' cannot self configure NICs eth1++. ' +
                        'No playbook  or keypairs found.')

    def get_image_user(self):
        """
        Returns the instance sudo_user if it has been configured in the instance_settings else it returns the
        image_settings.image_user value
        """
        if self.instance_settings.sudo_user:
            return self.instance_settings.sudo_user
        else:
            return self.image_settings.image_user

    def vm_deleted(self, block=False, poll_interval=POLL_INTERVAL):
        """
        Returns true when the VM status returns the value of expected_status_code or instance retrieval throws
        a NotFound exception.
        :param block: When true, thread will block until active or timeout value in seconds has been exceeded (False)
        :param poll_interval: The polling interval in seconds
        :return: T/F
        """
        try:
            return self.__vm_status_check(STATUS_DELETED, block, self.instance_settings.vm_delete_timeout,
                                          poll_interval)
        except NotFound as e:
            logger.debug("Instance not found when querying status for " + STATUS_DELETED + ' with message ' + e.message)
            return True

    def vm_active(self, block=False, poll_interval=POLL_INTERVAL):
        """
        Returns true when the VM status returns the value of expected_status_code
        :param block: When true, thread will block until active or timeout value in seconds has been exceeded (False)
        :param poll_interval: The polling interval in seconds
        :return: T/F
        """
        return self.__vm_status_check(STATUS_ACTIVE, block, self.instance_settings.vm_boot_timeout, poll_interval)

    def __vm_status_check(self, expected_status_code, block, timeout, poll_interval):
        """
        Returns true when the VM status returns the value of expected_status_code
        :param expected_status_code: instance status evaluated with this string value
        :param block: When true, thread will block until active or timeout value in seconds has been exceeded (False)
        :param timeout: The timeout value
        :param poll_interval: The polling interval in seconds
        :return: T/F
        """
        # sleep and wait for VM status change
        if block:
            start = time.time()
        else:
            start = time.time() - timeout

        while timeout > time.time() - start:
            status = self.__status(expected_status_code)
            if status:
                logger.info('VM is - ' + expected_status_code)
                return True

            logger.debug('Retry querying VM status in ' + str(poll_interval) + ' seconds')
            time.sleep(poll_interval)
            logger.debug('VM status query timeout in ' + str(timeout - (time.time() - start)))

        logger.error('Timeout checking for VM status for ' + expected_status_code)
        return False

    def __status(self, expected_status_code):
        """
        Returns True when active else False
        :param expected_status_code: instance status evaluated with this string value
        :return: T/F
        """
        instance = self.__nova.servers.get(self.__vm.id)
        if not instance:
            logger.warn('Cannot find instance with id - ' + self.__vm.id)
            return False

        if instance.status == 'ERROR':
            raise Exception('Instance had an error during deployment')
        logger.debug('Instance status [' + self.instance_settings.name + '] is - ' + instance.status)
        return instance.status == expected_status_code

    def vm_ssh_active(self, block=False, poll_interval=POLL_INTERVAL):
        """
        Returns true when the VM can be accessed via SSH
        :param block: When true, thread will block until active or timeout value in seconds has been exceeded (False)
        :param poll_interval: The polling interval
        :return: T/F
        """
        # sleep and wait for VM status change
        logger.info('Checking if VM is active')

        timeout = self.instance_settings.ssh_connect_timeout

        if self.vm_active(block=True):
            if block:
                start = time.time()
            else:
                start = time.time() - timeout

            while timeout > time.time() - start:
                status = self.__ssh_active()
                if status:
                    logger.info('SSH is active for VM instance')
                    return True

                logger.debug('Retry SSH connection in ' + str(poll_interval) + ' seconds')
                time.sleep(poll_interval)
                logger.debug('SSH connection timeout in ' + str(timeout - (time.time() - start)))

        logger.error('Timeout attempting to connect with VM via SSH')
        return False

    def __ssh_active(self):
        """
        Returns True when can create a SSH session else False
        :return: T/F
        """
        if len(self.__floating_ips) > 0:
            ssh = self.ssh_client()
            if ssh:
                return True
        return False

    def get_floating_ip(self, fip_name=None):
        """
        Returns the floating IP object byt name if found, else the first known, else None
        :param fip_name: the name of the floating IP to return
        :return: the SSH client or None
        """
        fip = None
        if fip_name and self.__floating_ip_dict.get(fip_name):
            return self.__floating_ip_dict.get(fip_name)
        if not fip and len(self.__floating_ips) > 0:
            return self.__floating_ips[0]
        return None

    def ssh_client(self, fip_name=None):
        """
        Returns an SSH client using the name or the first known floating IP if exists, else None
        :param fip_name: the name of the floating IP to return
        :return: the SSH client or None
        """
        fip = self.get_floating_ip(fip_name)
        if fip:
            return ansible_utils.ssh_client(self.__floating_ips[0].ip, self.get_image_user(),
                                            self.keypair_settings.private_filepath,
                                            proxy_settings=self.__os_creds.proxy_settings)
        else:
            logger.warn('Cannot return an SSH client. No Floating IP configured')

    def add_security_group(self, security_group):
        """
        Adds a security group to this VM. Call will block until VM is active.
        :param security_group: the OpenStack security group object
        :return True if successful else False
        """
        self.vm_active(block=True)

        if not security_group:
            logger.warn('Security group object is None, cannot add')
            return False

        try:
            nova_utils.add_security_group(self.__nova, self.get_vm_inst(), security_group['security_group']['name'])
            return True
        except NotFound as e:
            logger.warn('Security group not added - ' + e.message)
            return False

    def remove_security_group(self, security_group):
        """
        Removes a security group to this VM. Call will block until VM is active.
        :param security_group: the OpenStack security group object
        :return True if successful else False
        """
        self.vm_active(block=True)

        if not security_group:
            logger.warn('Security group object is None, cannot remove')
            return False

        try:
            nova_utils.remove_security_group(self.__nova, self.get_vm_inst(), security_group)
            return True
        except NotFound as e:
            logger.warn('Security group not removed - ' + e.message)
            return False


class VmInstanceSettings:
    """
    Class responsible for holding configuration setting for a VM Instance
    """
    def __init__(self, config=None, name=None, flavor=None, port_settings=list(), security_group_names=set(),
                 floating_ip_settings=list(), sudo_user=None, vm_boot_timeout=900,
                 vm_delete_timeout=300, ssh_connect_timeout=180, availability_zone=None, userdata=None):
        """
        Constructor
        :param config: dict() object containing the configuration settings using the attribute names below as each
                       member's the key and overrides any of the other parameters.
        :param name: the name of the VM
        :param flavor: the VM's flavor
        :param port_settings: the port configuration settings (required)
        :param security_group_names: a set of names of the security groups to add to the VM
        :param floating_ip_settings: the floating IP configuration settings
        :param sudo_user: the sudo user of the VM that will override the instance_settings.image_user when trying to
                          connect to the VM
        :param vm_boot_timeout: the amount of time a thread will sleep waiting for an instance to boot
        :param vm_delete_timeout: the amount of time a thread will sleep waiting for an instance to be deleted
        :param ssh_connect_timeout: the amount of time a thread will sleep waiting obtaining an SSH connection to a VM
        :param availability_zone: the name of the compute server on which to deploy the VM (optional)
        :param userdata: the cloud-init script to run after the VM has been started
        """
        if config:
            self.name = config.get('name')
            self.flavor = config.get('flavor')
            self.sudo_user = config.get('sudo_user')
            self.userdata = config.get('userdata')

            self.port_settings = list()
            if config.get('ports'):
                for port_config in config['ports']:
                    if isinstance(port_config, PortSettings):
                        self.port_settings.append(port_config)
                    else:
                        self.port_settings.append(PortSettings(config=port_config['port']))

            if config.get('security_group_names'):
                if isinstance(config['security_group_names'], list):
                    self.security_group_names = set(config['security_group_names'])
                elif isinstance(config['security_group_names'], set):
                    self.security_group_names = config['security_group_names']
                elif isinstance(config['security_group_names'], basestring):
                    self.security_group_names = [config['security_group_names']]
                else:
                    raise Exception('Invalid data type for security_group_names attribute')
            else:
                self.security_group_names = set()

            self.floating_ip_settings = list()
            if config.get('floating_ips'):
                for floating_ip_config in config['floating_ips']:
                    if isinstance(floating_ip_config, FloatingIpSettings):
                        self.floating_ip_settings.append(floating_ip_config)
                    else:
                        self.floating_ip_settings.append(FloatingIpSettings(config=floating_ip_config['floating_ip']))

            if config.get('vm_boot_timeout'):
                self.vm_boot_timeout = config['vm_boot_timeout']
            else:
                self.vm_boot_timeout = vm_boot_timeout

            if config.get('vm_delete_timeout'):
                self.vm_delete_timeout = config['vm_delete_timeout']
            else:
                self.vm_delete_timeout = vm_delete_timeout

            if config.get('ssh_connect_timeout'):
                self.ssh_connect_timeout = config['ssh_connect_timeout']
            else:
                self.ssh_connect_timeout = ssh_connect_timeout

            if config.get('availability_zone'):
                self.availability_zone = config['availability_zone']
            else:
                self.availability_zone = None
        else:
            self.name = name
            self.flavor = flavor
            self.port_settings = port_settings
            self.security_group_names = security_group_names
            self.floating_ip_settings = floating_ip_settings
            self.sudo_user = sudo_user
            self.vm_boot_timeout = vm_boot_timeout
            self.vm_delete_timeout = vm_delete_timeout
            self.ssh_connect_timeout = ssh_connect_timeout
            self.availability_zone = availability_zone
            self.userdata = userdata

        if not self.name or not self.flavor:
            raise Exception('Instance configuration requires the attributes: name, flavor')

        if len(self.port_settings) == 0:
            raise Exception('Instance configuration requires port settings (aka. NICS)')


class FloatingIpSettings:
    """
    Class responsible for holding configuration settings for a floating IP
    """
    def __init__(self, config=None, name=None, port_name=None, router_name=None, subnet_name=None, provisioning=True):
        """
        Constructor
        :param config: dict() object containing the configuration settings using the attribute names below as each
                       member's the key and overrides any of the other parameters.
        :param name: the name of the floating IP
        :param port_name: the name of the router to the external network
        :param router_name: the name of the router to the external network
        :param subnet_name: the name of the subnet on which to attach the floating IP
        :param provisioning: when true, this floating IP can be used for provisioning

        TODO - provisioning flag is a hack as I have only observed a single Floating IPs that actually works on
        an instance. Multiple floating IPs placed on different subnets from the same port are especially troublesome
        as you cannot predict which one will actually connect. For now, it is recommended not to setup multiple
        floating IPs on an instance unless absolutely necessary.
        """
        if config:
            self.name = config.get('name')
            self.port_name = config.get('port_name')
            self.router_name = config.get('router_name')
            self.subnet_name = config.get('subnet_name')
            if config.get('provisioning') is not None:
                self.provisioning = config['provisioning']
            else:
                self.provisioning = provisioning
        else:
            self.name = name
            self.port_name = port_name
            self.router_name = router_name
            self.subnet_name = subnet_name
            self.provisioning = provisioning

        if not self.name or not self.port_name or not self.router_name:
            raise Exception('The attributes name, port_name and router_name are required for FloatingIPSettings')