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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
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# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
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from libcloud.common.base import ConnectionKey, BaseDriver
from libcloud.common.types import LibcloudError
__all__ = [
'Member',
'LoadBalancer',
'Algorithm',
'Driver',
'DEFAULT_ALGORITHM'
]
[docs]class Member(object):
"""
Represents a load balancer member.
"""
def __init__(self, id, ip, port, balancer=None, extra=None):
"""
:param id: Member ID.
:type id: ``str``
:param ip: IP address of this member.
:param ip: ``str``
:param port: Port of this member
:param port: ``str``
:param balancer: Balancer this member is attached to. (optional)
:param balancer: :class:`.LoadBalancer`
:param extra: Provider specific attributes.
:type extra: ``dict``
"""
self.id = str(id) if id else None
self.ip = ip
self.port = port
self.balancer = balancer
self.extra = extra or {}
def __repr__(self):
return ('<Member: id=%s, address=%s:%s>' % (self.id,
self.ip, self.port))
[docs]class LoadBalancer(object):
"""
Provide a common interface for handling Load Balancers.
"""
def __init__(self, id, name, state, ip, port, driver, extra=None):
"""
:param id: Load balancer ID.
:type id: ``str``
:param name: Load balancer name.
:type name: ``str``
:param state: State this loadbalancer is in.
:type state: :class:`libcloud.loadbalancer.types.State`
:param ip: IP address of this loadbalancer.
:type ip: ``str``
:param port: Port of this loadbalancer.
:type port: ``int``
:param driver: Driver this loadbalancer belongs to.
:type driver: :class:`.Driver`
:param extra: Provier specific attributes. (optional)
:type extra: ``dict``
"""
self.id = str(id) if id else None
self.name = name
self.state = state
self.ip = ip
self.port = port
self.driver = driver
self.extra = extra or {}
def attach_compute_node(self, node):
return self.driver.balancer_attach_compute_node(balancer=self,
node=node)
def attach_member(self, member):
return self.driver.balancer_attach_member(balancer=self,
member=member)
def detach_member(self, member):
return self.driver.balancer_detach_member(balancer=self,
member=member)
def list_members(self):
return self.driver.balancer_list_members(balancer=self)
def destroy(self):
return self.driver.destroy_balancer(balancer=self)
def __repr__(self):
return ('<LoadBalancer: id=%s, name=%s, state=%s>' % (self.id,
self.name, self.state))
[docs]class Algorithm(object):
"""
Represents a load balancing algorithm.
"""
RANDOM = 0
ROUND_ROBIN = 1
LEAST_CONNECTIONS = 2
WEIGHTED_ROUND_ROBIN = 3
WEIGHTED_LEAST_CONNECTIONS = 4
DEFAULT_ALGORITHM = Algorithm.ROUND_ROBIN
[docs]class Driver(BaseDriver):
"""
A base Driver class to derive from
This class is always subclassed by a specific driver.
"""
name = None
website = None
connectionCls = ConnectionKey
_ALGORITHM_TO_VALUE_MAP = {}
_VALUE_TO_ALGORITHM_MAP = {}
def __init__(self, key, secret=None, secure=True, host=None,
port=None, **kwargs):
super(Driver, self).__init__(key=key, secret=secret, secure=secure,
host=host, port=port, **kwargs)
[docs] def list_protocols(self):
"""
Return a list of supported protocols.
:rtype: ``list`` of ``str``
"""
raise NotImplementedError(
'list_protocols not implemented for this driver')
[docs] def list_balancers(self):
"""
List all loadbalancers
:rtype: ``list`` of :class:`LoadBalancer`
"""
raise NotImplementedError(
'list_balancers not implemented for this driver')
[docs] def create_balancer(self, name, port, protocol, algorithm, members):
"""
Create a new load balancer instance
:param name: Name of the new load balancer (required)
:type name: ``str``
:param port: Port the load balancer should listen on, defaults to 80
:type port: ``str``
:param protocol: Loadbalancer protocol, defaults to http.
:type protocol: ``str``
:param members: list of Members to attach to balancer
:type members: ``list`` of :class:`Member`
:param algorithm: Load balancing algorithm, defaults to ROUND_ROBIN.
:type algorithm: :class:`Algorithm`
:rtype: :class:`LoadBalancer`
"""
raise NotImplementedError(
'create_balancer not implemented for this driver')
[docs] def destroy_balancer(self, balancer):
"""
Destroy a load balancer
:param balancer: LoadBalancer which should be used
:type balancer: :class:`LoadBalancer`
:return: ``True`` if the destroy was successful, otherwise ``False``.
:rtype: ``bool``
"""
raise NotImplementedError(
'destroy_balancer not implemented for this driver')
[docs] def get_balancer(self, balancer_id):
"""
Return a :class:`LoadBalancer` object.
:param balancer_id: id of a load balancer you want to fetch
:type balancer_id: ``str``
:rtype: :class:`LoadBalancer`
"""
raise NotImplementedError(
'get_balancer not implemented for this driver')
[docs] def update_balancer(self, balancer, **kwargs):
"""
Sets the name, algorithm, protocol, or port on a load balancer.
:param balancer: LoadBalancer which should be used
:type balancer: :class:`LoadBalancer`
:param name: New load balancer name
:type name: ``str``
:param algorithm: New load balancer algorithm
:type algorithm: :class:`Algorithm`
:param protocol: New load balancer protocol
:type protocol: ``str``
:param port: New load balancer port
:type port: ``int``
:rtype: :class:`LoadBalancer`
"""
raise NotImplementedError(
'update_balancer not implemented for this driver')
[docs] def balancer_attach_compute_node(self, balancer, node):
"""
Attach a compute node as a member to the load balancer.
:param balancer: LoadBalancer which should be used
:type balancer: :class:`LoadBalancer`
:param node: Node to join to the balancer
:type node: :class:`Node`
:return: Member after joining the balancer.
:rtype: :class:`Member`
"""
member = Member(id=None, ip=node.public_ips[0], port=balancer.port)
return self.balancer_attach_member(balancer, member)
[docs] def balancer_attach_member(self, balancer, member):
"""
Attach a member to balancer
:param balancer: LoadBalancer which should be used
:type balancer: :class:`LoadBalancer`
:param member: Member to join to the balancer
:type member: :class:`Member`
:return: Member after joining the balancer.
:rtype: :class:`Member`
"""
raise NotImplementedError(
'balancer_attach_member not implemented for this driver')
[docs] def balancer_detach_member(self, balancer, member):
"""
Detach member from balancer
:param balancer: LoadBalancer which should be used
:type balancer: :class:`LoadBalancer`
:param member: Member which should be used
:type member: :class:`Member`
:return: ``True`` if member detach was successful, otherwise ``False``.
:rtype: ``bool``
"""
raise NotImplementedError(
'balancer_detach_member not implemented for this driver')
[docs] def balancer_list_members(self, balancer):
"""
Return list of members attached to balancer
:param balancer: LoadBalancer which should be used
:type balancer: :class:`LoadBalancer`
:rtype: ``list`` of :class:`Member`
"""
raise NotImplementedError(
'balancer_list_members not implemented for this driver')
[docs] def list_supported_algorithms(self):
"""
Return algorithms supported by this driver.
:rtype: ``list`` of ``str``
"""
return list(self._ALGORITHM_TO_VALUE_MAP.keys())
def _value_to_algorithm(self, value):
"""
Return :class`Algorithm` based on the value.
:param value: Algorithm name (e.g. http, tcp, ...).
:type value: ``str``
@rype :class:`Algorithm`
"""
try:
return self._VALUE_TO_ALGORITHM_MAP[value]
except KeyError:
raise LibcloudError(value='Invalid value: %s' % (value),
driver=self)
def _algorithm_to_value(self, algorithm):
"""
Return string value for the provided algorithm.
:param value: Algorithm enum.
:type value: :class:`Algorithm`
@rype ``str``
"""
try:
return self._ALGORITHM_TO_VALUE_MAP[algorithm]
except KeyError:
raise LibcloudError(value='Invalid algorithm: %s' % (algorithm),
driver=self)