Source code for geni.rspec.emulab.emuext

# Copyright (c) 2016 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 EmulabExtensionDuplicateStatement(Exception): """This exception gets thrown if something that was only supposed to get added once to a Request, Node, Link, etc. gets added multiple times.""" def __init__ (self, classname): self._classname = classname def __str__ (self): return "%s may be used only once!" % str(self._classname,)
[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. """ _mfactor = None def __init__(self, mfactor): """mfactor is an integer, giving the maximum number of VMs to multiplex on each physical host.""" if setCollocateFactor._mfactor: raise EmulabExtensionDuplicateStatement("setCollocateFactor") self.mfactor = setCollocateFactor._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 """ _strategy = None def __init__(self, strategy): if setPackingStrategy._strategy: raise EmulabExtensionDuplicateStatement("setPackingStrategy") self.strategy = setPackingStrategy._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. """ _style = None def __init__(self, style): if setRoutingStyle._style: raise EmulabExtensionDuplicateStatement("setRoutingStyle") self.style = setRoutingStyle._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. """ _urn = None 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. """ if setDelayImage._urn: raise EmulabExtensionDuplicateStatement("setDelayImage") self.urn = setDelayImage._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. """ _enabled = False 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)) 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. """ _enabled = False 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)) # # 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)
_parent = None 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. # Request.EXTENSIONS.append(("BridgedLink", BridgedLink)) Request.EXTENSIONS.append(("ShapedLink", ShapedLink))