# Copyright (c) 2016-2017 The University of Utah
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
"""
Common set of RSpec extensions supported by many Emulab-based aggregates
"""
from __future__ import absolute_import
from ..pg import Request, Namespaces, Link, Node, Service, Command, RawPC
import geni.namespaces as GNS
from lxml import etree as ET
[docs]class setCollocateFactor(object):
"""Added to a top-level Request object, this extension limits the number
of VMs from one experiment that Emulab will collocate on each physical
host.
"""
__ONCEONLY__ = True
def __init__(self, mfactor):
"""mfactor is an integer, giving the maximum number of VMs to multiplex
on each physical host."""
self.mfactor = mfactor
def _write(self, root):
el = ET.SubElement(root,
"{%s}collocate_factor" % (Namespaces.EMULAB.name))
el.attrib["count"] = str(self.mfactor)
return root
Request.EXTENSIONS.append(("setCollocateFactor", setCollocateFactor))
[docs]class setPackingStrategy(object):
"""Added to a top-level Request object, this extension controls the
strategy used for distributing VMs across physical hosts
"""
__ONCEONLY__ = True
def __init__(self, strategy):
self.strategy = strategy
def _write(self, root):
el = ET.SubElement(root,
"{%s}packing_strategy" % (Namespaces.EMULAB.name))
el.attrib["strategy"] = str(self.strategy)
return root
Request.EXTENSIONS.append(("setPackingStrategy", setPackingStrategy))
[docs]class setRoutingStyle(object):
"""Added to a top-level Request object, this extension controls the
routing that is automatically configured on the experiment (data-plane)
side of the network.
"""
__ONCEONLY__ = True
def __init__(self, style):
self.style = style
def _write(self, root):
el = ET.SubElement(root,
"{%s}routing_style" % (Namespaces.EMULAB.name))
el.attrib["style"] = str(self.style)
return root
Request.EXTENSIONS.append(("setRoutingStyle", setRoutingStyle))
[docs]class setDelayImage(object):
"""Added to a top-level Request object, this extension sets the disk image
that will be used for all delay nodes configured for the experiment.
"""
__ONCEONLY__ = True
def __init__(self, urn):
"""urn: URN of any image - to perform the intnded function, the
image must be capable of setting up bridging and/or traffic shaping.
"""
self.urn = urn
def _write(self, root):
el = ET.SubElement(root,
"{%s}delay_image" % (Namespaces.EMULAB.name))
el.attrib["urn"] = str(self.urn)
return root
Request.EXTENSIONS.append(("setDelayImage", setDelayImage))
[docs]class setForceShaping(object):
"""Added to a Link or LAN object, this extension forces Emulab link
shaping to be enabled, even if it is not strictly necessary. This
allows the link properties to be changed dynamically via the Emulab event
system.
"""
__ONCEONLY__ = True
def __init__(self):
self._enabled = True
def _write(self, root):
if self._enabled == False:
return root
el = ET.SubElement(root, "{%s}force_shaping" % (Namespaces.EMULAB.name))
el.attrib["enabled"] = "true"
return root
Link.EXTENSIONS.append(("setForceShaping", setForceShaping))
[docs]class setNoBandwidthShaping(object):
"""Added to a Link or LAN object, this extension forces Emulab link
shaping to be disabled for bandwidth, even if it is necessary. This
is ignored if the link must be shaped for other reason (delay, loss).
"""
__ONCEONLY__ = True
def __init__(self):
self._enabled = True
def _write(self, root):
if self._enabled == False:
return root
el = ET.SubElement(root,
"{%s}force_nobwshaping" % (Namespaces.EMULAB.name))
el.attrib["enabled"] = "true"
return root
Link.EXTENSIONS.append(("setNoBandwidthShaping", setNoBandwidthShaping))
[docs]class setNoInterSwitchLinks(object):
"""Added to a Link or LAN object, this extension forces the Emulab mapper
to disallow mapping a link in the request topology to an inter-switch
link. This allows users to require that specific nodes in their
topology be attached to the same switch(es).
"""
__ONCEONLY__ = True
def __init__(self):
self._enabled = True
def _write(self, root):
if self._enabled == False:
return root
el = ET.SubElement(root, "{%s}interswitch" % (Namespaces.EMULAB.name))
el.attrib["allow"] = "false"
return root
Link.EXTENSIONS.append(("setNoInterSwitchLinks", setNoInterSwitchLinks))
[docs]class setUseTypeDefaultImage(object):
"""Added to a node that does not specify a disk image, this extension
forces Emulab to use the hardware type default image instead of the
standard geni default image. Useful with special hardware that should
run a special image.
"""
__ONCEONLY__ = True
def __init__(self):
self._enabled = True
def _write(self, root):
if self._enabled == False:
return root
el = ET.SubElement(root, "{%s}use_type_default_image"
% (Namespaces.EMULAB.name))
el.attrib["enabled"] = "true"
return root
Node.EXTENSIONS.append(("setUseTypeDefaultImage", setUseTypeDefaultImage))
[docs]class setFailureAction(object):
"""Added to a node this extension will tell Emulab based aggregates to
ignore errors booting this node when starting an experiment. This allows
the experiment to proceed so that the user has time to debug."""
__ONCEONLY__ = True
def __init__(self, action):
self.action = action
self._enabled = True
def _write(self, root):
if self._enabled == False:
return root
el = ET.SubElement(root, "{%s}failure_action" % (Namespaces.EMULAB.name))
el.attrib["action"] = self.action
return root
Node.EXTENSIONS.append(("setFailureAction", setFailureAction))
#
# Emulab Program Agents.
#
[docs]class ProgramAgent(Service):
"""Add an Emulab Program Agent, which can be controlled via the Emulab
event system. Optional argument 'directory' specifies where to invoke
the command from. Optional argument 'onexpstart' says to invoke the
command when the experiment starts (time=0 in event speak). This is
different than the Execute service, which runs every time the node boots.
"""
def __init__ (self, name, command, directory = None, onexpstart = False):
super(ProgramAgent, self).__init__()
self.name = name
self.command = command
self.directory = directory
self.onexpstart = onexpstart
def _write (self, element):
exc = ET.SubElement(element,
"{%s}program-agent" % (Namespaces.EMULAB.name))
exc.attrib["name"] = self.name
if isinstance(self.command, Command):
exc.attrib["command"] = self.command.resolve()
else:
exc.attrib["command"] = self.command
if self.directory:
exc.attrib["directory"] = self.directory
if self.onexpstart:
exc.attrib["onexpstart"] = "true"
return exc
[docs]class InstantiateOn(object):
"""Added to a node to specify that it a Xen VM should be bound to
(instantiated on) another node in the topology. Argument is the
node instance or the client id of another node in the topology.
"""
[docs] class InvalidParent(Exception):
def __init__ (self, parent):
super(InstantiateOn.InvalidParent, self).__init__()
self.parent = parent
def __str__ (self):
return "%s is not a Raw PC" % (self.parent.name)
__ONCEONLY__ = True
def __init__(self, parent):
if isinstance(parent, Node):
# Xen VMs have to be bound to a raw PC.
if not isinstance(parent, RawPC):
raise InvalidParent(parent)
self._parent = parent.name
else:
# Allow plain name to be used. At the moment the NS converter
# is not trying to order nodes, so the vhost might not be
# first.
self._parent = parent
def _write(self, root):
if self._parent == None:
return root
el = ET.SubElement(root, "{%s}relation" % (GNS.REQUEST.name))
el.attrib["type"] = "instantiate_on"
el.attrib["client_id"] = self._parent
return root
Node.EXTENSIONS.append(("InstantiateOn", InstantiateOn))
#
# A Bridged Link is syntatic sugar for two links separated by a bridge
# node acting as a delay node.
#
# Unfortunately, there is no way to get a handle on the parent object
# of an extension, so we need to get that explicitly.
#
[docs]class BridgedLink(object):
"""A bridged link is syntactic sugar used to create two links
separated by an Emulab delay (bridge) node. The BridgedLink class will
create the following topology:
left-link right-link
node1 =========== bridge ============ node2
The bridge is a special node type (sliver_type="delay") that tells the
CM to insert an Emulab delay node instead of a plain (router) node. A
delay node is a transparent Ethernet bridge between the left and right
segments above, but on which the traffic can be shaped wrt. bandwidth,
latency, and loss. For example:
# Create the bridged link between the two nodes.
link = request.BridgedLink("link")
# Add two interfaces
link.addInterface(iface1)
link.addInterface(iface2)
# Give the link (bridge) some shaping parameters.
link.bandwidth = 10000
link.latency = 15
link.plr = 0.01"""
# This tells the Request class to set the _parent member after creating the
# object
__WANTPARENT__ = True;
def __init__ (self, name = None):
if name is None:
self.name = Link.newLinkID()
else:
self.name = name
self.bridge_name = name + "_bridge"
self.left_name = name + "_left"
self.right_name = name + "_right"
self.left_iface = None
self.right_iface = None
self._bandwidth = Link.DEFAULT_BW
self._latency = Link.DEFAULT_LAT
self._plr = Link.DEFAULT_PLR
# This needs to get set with the setter; this helps us remember that we
# have not been attached to a parent
self.request = None
# These will be set later when we know the parent
self.bridge = None
self.left_link = None
self.right_link = None
@property
def _parent(self):
return self.request
@_parent.setter
def _parent(self, request):
self.request = request
self.bridge = request.Bridge(self.bridge_name)
self.left_link = request.Link(self.left_name)
self.left_link.addInterface(self.bridge.iface0);
self.right_link = request.Link(self.right_name)
self.right_link.addInterface(self.bridge.iface1);
[docs] def addInterface(self, interface):
if self.left_iface == None:
self.left_link.addInterface(interface)
self.left_iface = interface
else:
self.right_link.addInterface(interface)
self.right_iface = interface
@property
def bandwidth (self):
return self._bandwidth
@bandwidth.setter
def bandwidth (self, val):
self.bridge.pipe0.bandwidth = val;
self.bridge.pipe1.bandwidth = val;
self._bandwidth = val
@property
def latency (self):
return self._latency
@latency.setter
def latency (self, val):
self.bridge.pipe0.latency = val;
self.bridge.pipe1.latency = val;
self._latency = val
@property
def plr (self):
return self._plr
@plr.setter
def plr (self, val):
self.bridge.pipe0.lossrate = val;
self.bridge.pipe1.lossrate = val;
self._plr = val
def _write(self, root):
return root
Request.EXTENSIONS.append(("BridgedLink", BridgedLink))
[docs]class ShapedLink(BridgedLink):
"""A ShapedLink is a synonym for BridgedLink"""
def __init__ (self, name = None):
super(ShapedLink, self).__init__(name=name)
Request.EXTENSIONS.append(("ShapedLink", ShapedLink))