source: fedd/federation/experiment_control.py @ e07c8f3

#!/usr/local/bin/python

import os,sys

import re
import random
import string
import subprocess
import tempfile
import copy
import pickle
import logging
import signal
import time

import traceback
# For parsing visualization output and splitter output
import xml.parsers.expat

from threading import Lock, Thread, Condition
from subprocess import call, Popen, PIPE

from urlparse import urlparse
from urllib2 import urlopen

from util import *
from fedid import fedid, generate_fedid
from remote_service import xmlrpc_handler, soap_handler, service_caller
from service_error import service_error
from synch_store import synch_store
from experiment_partition import experiment_partition

import topdl
import list_log
from ip_allocator import ip_allocator
from ip_addr import ip_addr


class nullHandler(logging.Handler):
    def emit(self, record): pass

fl = logging.getLogger("fedd.experiment_control")
fl.addHandler(nullHandler())


# Right now, no support for composition.
class federated_service:
    def __init__(self, name, exporter=None, importers=None, params=None, 
            reqs=None, portal=None):
        self.name=name
        self.exporter=exporter
        if importers is None: self.importers = []
        else: self.importers=importers
        if params is None: self.params = { }
        else: self.params = params
        if reqs is None: self.reqs = []
        else: self.reqs = reqs

        if portal is not None:
            self.portal = portal
        else:
            self.portal = (name in federated_service.needs_portal)

    def __str__(self):
        return "name %s export %s import %s params %s reqs %s" % \
                (self.name, self.exporter, self.importers, self.params,
                        [ (r['name'], r['visibility']) for r in self.reqs] )

    needs_portal = ('SMB', 'seer', 'tmcd', 'project_export', 'seer_master')

class experiment_control_local:
    """
    Control of experiments that this system can directly access.

    Includes experiment creation, termination and information dissemination.
    Thred safe.
    """

    class ssh_cmd_timeout(RuntimeError): pass
    
    class thread_pool:
        """
        A class to keep track of a set of threads all invoked for the same
        task.  Manages the mutual exclusion of the states.
        """
        def __init__(self, nthreads):
            """
            Start a pool.
            """
            self.changed = Condition()
            self.started = 0
            self.terminated = 0
            self.nthreads = nthreads

        def acquire(self):
            """
            Get the pool's lock.
            """
            self.changed.acquire()

        def release(self):
            """
            Release the pool's lock.
            """
            self.changed.release()

        def wait(self, timeout = None):
            """
            Wait for a pool thread to start or stop.
            """
            self.changed.wait(timeout)

        def start(self):
            """
            Called by a pool thread to report starting.
            """
            self.changed.acquire()
            self.started += 1
            self.changed.notifyAll()
            self.changed.release()

        def terminate(self):
            """
            Called by a pool thread to report finishing.
            """
            self.changed.acquire()
            self.terminated += 1
            self.changed.notifyAll()
            self.changed.release()

        def clear(self):
            """
            Clear all pool data.
            """
            self.changed.acquire()
            self.started = 0
            self.terminated =0
            self.changed.notifyAll()
            self.changed.release()

        def wait_for_slot(self):
            """
            Wait until we have a free slot to start another pooled thread
            """
            self.acquire()
            while self.started - self.terminated >= self.nthreads:
                self.wait()
            self.release()

        def wait_for_all_done(self, timeout=None):
            """
            Wait until all active threads finish (and at least one has
            started).  If a timeout is given, return after waiting that long
            for termination.  If all threads are done (and one has started in
            the since the last clear()) return True, otherwise False.
            """
            if timeout:
                deadline = time.time() + timeout
            self.acquire()
            while self.started == 0 or self.started > self.terminated:
                self.wait(timeout)
                if timeout:
                    if time.time() > deadline:
                        break
                    timeout = deadline - time.time()
            self.release()
            return not (self.started == 0 or self.started > self.terminated)

    class pooled_thread(Thread):
        """
        One of a set of threads dedicated to a specific task.  Uses the
        thread_pool class above for coordination.
        """
        def __init__(self, group=None, target=None, name=None, args=(), 
                kwargs={}, pdata=None, trace_file=None):
            Thread.__init__(self, group, target, name, args, kwargs)
            self.rv = None          # Return value of the ops in this thread
            self.exception = None   # Exception that terminated this thread
            self.target=target      # Target function to run on start()
            self.args = args        # Args to pass to target
            self.kwargs = kwargs    # Additional kw args
            self.pdata = pdata      # thread_pool for this class
            # Logger for this thread
            self.log = logging.getLogger("fedd.experiment_control")
        
        def run(self):
            """
            Emulate Thread.run, except add pool data manipulation and error
            logging.
            """
            if self.pdata:
                self.pdata.start()

            if self.target:
                try:
                    self.rv = self.target(*self.args, **self.kwargs)
                except service_error, s:
                    self.exception = s
                    self.log.error("Thread exception: %s %s" % \
                            (s.code_string(), s.desc))
                except:
                    self.exception = sys.exc_info()[1]
                    self.log.error(("Unexpected thread exception: %s" +\
                            "Trace %s") % (self.exception,\
                                traceback.format_exc()))
            if self.pdata:
                self.pdata.terminate()

    call_RequestAccess = service_caller('RequestAccess')
    call_ReleaseAccess = service_caller('ReleaseAccess')
    call_StartSegment = service_caller('StartSegment')
    call_TerminateSegment = service_caller('TerminateSegment')
    call_Ns2Topdl = service_caller('Ns2Topdl')

    def __init__(self, config=None, auth=None):
        """
        Intialize the various attributes, most from the config object
        """

        def parse_tarfile_list(tf):
            """
            Parse a tarfile list from the configuration.  This is a set of
            paths and tarfiles separated by spaces.
            """
            rv = [ ]
            if tf is not None:
                tl = tf.split()
                while len(tl) > 1:
                    p, t = tl[0:2]
                    del tl[0:2]
                    rv.append((p, t))
            return rv

        self.thread_with_rv = experiment_control_local.pooled_thread
        self.thread_pool = experiment_control_local.thread_pool
        self.list_log = list_log.list_log

        self.cert_file = config.get("experiment_control", "cert_file")
        if self.cert_file:
            self.cert_pwd = config.get("experiment_control", "cert_pwd")
        else:
            self.cert_file = config.get("globals", "cert_file")
            self.cert_pwd = config.get("globals", "cert_pwd")

        self.trusted_certs = config.get("experiment_control", "trusted_certs") \
                or config.get("globals", "trusted_certs")

        self.repodir = config.get("experiment_control", "repodir")
        self.repo_url = config.get("experiment_control", "repo_url", 
                "https://users.isi.deterlab.net:23235");

        self.exp_stem = "fed-stem"
        self.log = logging.getLogger("fedd.experiment_control")
        set_log_level(config, "experiment_control", self.log)
        self.muxmax = 2
        self.nthreads = 10
        self.randomize_experiments = False

        self.splitter = None
        self.ssh_keygen = "/usr/bin/ssh-keygen"
        self.ssh_identity_file = None


        self.debug = config.getboolean("experiment_control", "create_debug")
        self.cleanup = not config.getboolean("experiment_control", 
                "leave_tmpfiles")
        self.state_filename = config.get("experiment_control", 
                "experiment_state")
        self.store_filename = config.get("experiment_control", 
                "synch_store")
        self.store_url = config.get("experiment_control", "store_url")
        self.splitter_url = config.get("experiment_control", "ns2topdl_uri")
        self.fedkit = parse_tarfile_list(\
                config.get("experiment_control", "fedkit"))
        self.gatewaykit = parse_tarfile_list(\
                config.get("experiment_control", "gatewaykit"))
        accessdb_file = config.get("experiment_control", "accessdb")

        self.ssh_pubkey_file = config.get("experiment_control", 
                "ssh_pubkey_file")
        self.ssh_privkey_file = config.get("experiment_control",
                "ssh_privkey_file")
        dt = config.get("experiment_control", "direct_transit")
        if dt: self.direct_transit = [ tb.strip() for tb in dt.split(",")]
        else: self.direct_transit = [ ]
        # NB for internal master/slave ops, not experiment setup
        self.ssh_type = config.get("experiment_control", "sshkeytype", "rsa")

        self.overrides = set([])
        ovr = config.get('experiment_control', 'overrides')
        if ovr:
            for o in ovr.split(","):
                o = o.strip()
                if o.startswith('fedid:'): o = o[len('fedid:'):]
                self.overrides.add(fedid(hexstr=o))

        self.state = { }
        self.state_lock = Lock()
        self.tclsh = "/usr/local/bin/otclsh"
        self.tcl_splitter = config.get("ns2topdl", "tcl_splitter") or \
                config.get("experiment_control", "tcl_splitter",
                        "/usr/testbed/lib/ns2ir/parse.tcl")
        mapdb_file = config.get("experiment_control", "mapdb")
        self.trace_file = sys.stderr

        self.def_expstart = \
                "sudo -H /bin/sh /usr/local/federation/bin/federate.sh >& " +\
                "/tmp/federate";
        self.def_mexpstart = "sudo -H /usr/local/federation/bin/make_hosts " +\
                "FEDDIR/hosts";
        self.def_gwstart = \
                "sudo -H /usr/local/federation/bin/fed-tun.pl -f GWCONF>& " +\
                "/tmp/bridge.log";
        self.def_mgwstart = \
                "sudo -H /usr/local/federation/bin/fed-tun.pl -f GWCONF >& " +\
                "/tmp/bridge.log";
        self.def_gwimage = "FBSD61-TUNNEL2";
        self.def_gwtype = "pc";
        self.local_access = { }

        if auth:
            self.auth = auth
        else:
            self.log.error(\
                    "[access]: No authorizer initialized, creating local one.")
            auth = authorizer()


        if self.ssh_pubkey_file:
            try:
                f = open(self.ssh_pubkey_file, 'r')
                self.ssh_pubkey = f.read()
                f.close()
            except EnvironmentError:
                raise service_error(service_error.internal,
                        "Cannot read sshpubkey")
        else:
            raise service_error(service_error.internal, 
                    "No SSH public key file?")

        if not self.ssh_privkey_file:
            raise service_error(service_error.internal, 
                    "No SSH public key file?")


        if mapdb_file:
            self.read_mapdb(mapdb_file)
        else:
            self.log.warn("[experiment_control] No testbed map, using defaults")
            self.tbmap = { 
                    'deter':'https://users.isi.deterlab.net:23235',
                    'emulab':'https://users.isi.deterlab.net:23236',
                    'ucb':'https://users.isi.deterlab.net:23237',
                    }

        if accessdb_file:
                self.read_accessdb(accessdb_file)
        else:
            raise service_error(service_error.internal,
                    "No accessdb specified in config")

        # Grab saved state.  OK to do this w/o locking because it's read only
        # and only one thread should be in existence that can see self.state at
        # this point.
        if self.state_filename:
            self.read_state()

        if self.store_filename:
            self.read_store()
        else:
            self.log.warning("No saved synch store")
            self.synch_store = synch_store

        # Dispatch tables
        self.soap_services = {\
                'New': soap_handler('New', self.new_experiment),
                'Create': soap_handler('Create', self.create_experiment),
                'Vtopo': soap_handler('Vtopo', self.get_vtopo),
                'Vis': soap_handler('Vis', self.get_vis),
                'Info': soap_handler('Info', self.get_info),
                'MultiInfo': soap_handler('MultiInfo', self.get_multi_info),
                'Terminate': soap_handler('Terminate', 
                    self.terminate_experiment),
                'GetValue': soap_handler('GetValue', self.GetValue),
                'SetValue': soap_handler('SetValue', self.SetValue),
        }

        self.xmlrpc_services = {\
                'New': xmlrpc_handler('New', self.new_experiment),
                'Create': xmlrpc_handler('Create', self.create_experiment),
                'Vtopo': xmlrpc_handler('Vtopo', self.get_vtopo),
                'Vis': xmlrpc_handler('Vis', self.get_vis),
                'Info': xmlrpc_handler('Info', self.get_info),
                'MultiInfo': xmlrpc_handler('MultiInfo', self.get_multi_info),
                'Terminate': xmlrpc_handler('Terminate',
                    self.terminate_experiment),
                'GetValue': xmlrpc_handler('GetValue', self.GetValue),
                'SetValue': xmlrpc_handler('SetValue', self.SetValue),
        }

    # Call while holding self.state_lock
    def write_state(self):
        """
        Write a new copy of experiment state after copying the existing state
        to a backup.

        State format is a simple pickling of the state dictionary.
        """
        if os.access(self.state_filename, os.W_OK):
            copy_file(self.state_filename, \
                    "%s.bak" % self.state_filename)
        try:
            f = open(self.state_filename, 'w')
            pickle.dump(self.state, f)
        except EnvironmentError, e:
            self.log.error("Can't write file %s: %s" % \
                    (self.state_filename, e))
        except pickle.PicklingError, e:
            self.log.error("Pickling problem: %s" % e)
        except TypeError, e:
            self.log.error("Pickling problem (TypeError): %s" % e)

    @staticmethod
    def get_alloc_ids(state):
        """
        Pull the fedids of the identifiers of each allocation from the
        state.  Again, a dict dive that's best isolated.

        Used by read_store and read state
        """

        return [ f['allocID']['fedid'] 
                for f in state.get('federant',[]) \
                    if f.has_key('allocID') and \
                        f['allocID'].has_key('fedid')]

    # Call while holding self.state_lock
    def read_state(self):
        """
        Read a new copy of experiment state.  Old state is overwritten.

        State format is a simple pickling of the state dictionary.
        """
        
        def get_experiment_id(state):
            """
            Pull the fedid experimentID out of the saved state.  This is kind
            of a gross walk through the dict.
            """

            if state.has_key('experimentID'):
                for e in state['experimentID']:
                    if e.has_key('fedid'):
                        return e['fedid']
                else:
                    return None
            else:
                return None

        try:
            f = open(self.state_filename, "r")
            self.state = pickle.load(f)
            self.log.debug("[read_state]: Read state from %s" % \
                    self.state_filename)
        except EnvironmentError, e:
            self.log.warning("[read_state]: No saved state: Can't open %s: %s"\
                    % (self.state_filename, e))
        except pickle.UnpicklingError, e:
            self.log.warning(("[read_state]: No saved state: " + \
                    "Unpickling failed: %s") % e)
        
        for s in self.state.values():
            try:

                eid = get_experiment_id(s)
                if eid : 
                    # Give the owner rights to the experiment
                    self.auth.set_attribute(s['owner'], eid)
                    # And holders of the eid as well
                    self.auth.set_attribute(eid, eid)
                    # allow overrides to control experiments as well
                    for o in self.overrides:
                        self.auth.set_attribute(o, eid)
                    # Set permissions to allow reading of the software repo, if
                    # any, as well.
                    for a in self.get_alloc_ids(s):
                        self.auth.set_attribute(a, 'repo/%s' % eid)
                else:
                    raise KeyError("No experiment id")
            except KeyError, e:
                self.log.warning("[read_state]: State ownership or identity " +\
                        "misformatted in %s: %s" % (self.state_filename, e))


    def read_accessdb(self, accessdb_file):
        """
        Read the mapping from fedids that can create experiments to their name
        in the 3-level access namespace.  All will be asserted from this
        testbed and can include the local username and porject that will be
        asserted on their behalf by this fedd.  Each fedid is also added to the
        authorization system with the "create" attribute.
        """
        self.accessdb = {}
        # These are the regexps for parsing the db
        name_expr = "[" + string.ascii_letters + string.digits + "\.\-]+"
        project_line = re.compile("^\s*fedid:([" + string.hexdigits + "]+)"+ \
                "\s*->\(\s*("+name_expr+")\s*,\s*("+name_expr+")\s*\)\s*$")
        user_line = re.compile("^\s*fedid:([" + string.hexdigits + "]+)"+ \
                "\s*->\s*(" + name_expr + ")\s*$")
        lineno = 0

        # Parse the mappings and store in self.authdb, a dict of 
        # fedid -> (proj, user)
        try:
            f = open(accessdb_file, "r")
            for line in f:
                lineno += 1
                line = line.strip()
                if len(line) == 0 or line.startswith('#'):
                    continue
                m = project_line.match(line)
                if m:
                    fid = fedid(hexstr=m.group(1))
                    project, user = m.group(2,3)
                    if not self.accessdb.has_key(fid):
                        self.accessdb[fid] = []
                    self.accessdb[fid].append((project, user))
                    continue

                m = user_line.match(line)
                if m:
                    fid = fedid(hexstr=m.group(1))
                    project = None
                    user = m.group(2)
                    if not self.accessdb.has_key(fid):
                        self.accessdb[fid] = []
                    self.accessdb[fid].append((project, user))
                    continue
                self.log.warn("[experiment_control] Error parsing access " +\
                        "db %s at line %d" %  (accessdb_file, lineno))
        except EnvironmentError:
            raise service_error(service_error.internal,
                    ("Error opening/reading %s as experiment " +\
                            "control accessdb") %  accessdb_file)
        f.close()

        # Initialize the authorization attributes
        for fid in self.accessdb.keys():
            self.auth.set_attribute(fid, 'create')
            self.auth.set_attribute(fid, 'new')

    def read_mapdb(self, file):
        """
        Read a simple colon separated list of mappings for the
        label-to-testbed-URL mappings.  Clears or creates self.tbmap.
        """

        self.tbmap = { }
        lineno =0
        try:
            f = open(file, "r")
            for line in f:
                lineno += 1
                line = line.strip()
                if line.startswith('#') or len(line) == 0:
                    continue
                try:
                    label, url = line.split(':', 1)
                    self.tbmap[label] = url
                except ValueError, e:
                    self.log.warn("[read_mapdb] Ignored bad line (%d) in " +\
                            "map db: %s %s" % (lineno, line, e))
        except EnvironmentError, e:
            self.log.warning("[read_mapdb]: No saved map database: Can't " +\
                    "open %s: %s" % (file, e))
        f.close()

    def read_store(self):
        try:
            self.synch_store = synch_store()
            self.synch_store.load(self.store_filename)
            self.log.debug("[read_store]: Read store from %s" % \
                    self.store_filename)
        except EnvironmentError, e:
            self.log.warning("[read_store]: No saved store: Can't open %s: %s"\
                    % (self.state_filename, e))
            self.synch_store = synch_store()

        # Set the initial permissions on data in the store.  XXX: This ad hoc
        # authorization attribute initialization is getting out of hand.
        for k in self.synch_store.all_keys():
            try:
                if k.startswith('fedid:'):
                    fid = fedid(hexstr=k[6:46])
                    if self.state.has_key(fid):
                        for a in self.get_alloc_ids(self.state[fid]):
                            self.auth.set_attribute(a, k)
            except ValueError, e:
                self.log.warn("Cannot deduce permissions for %s" % k)


    def write_store(self):
        """
        Write a new copy of synch_store after writing current state
        to a backup.  We use the internal synch_store pickle method to avoid
        incinsistent data.

        State format is a simple pickling of the store.
        """
        if os.access(self.store_filename, os.W_OK):
            copy_file(self.store_filename, \
                    "%s.bak" % self.store_filename)
        try:
            self.synch_store.save(self.store_filename)
        except EnvironmentError, e:
            self.log.error("Can't write file %s: %s" % \
                    (self.store_filename, e))
        except TypeError, e:
            self.log.error("Pickling problem (TypeError): %s" % e)

        
    def generate_ssh_keys(self, dest, type="rsa" ):
        """
        Generate a set of keys for the gateways to use to talk.

        Keys are of type type and are stored in the required dest file.
        """
        valid_types = ("rsa", "dsa")
        t = type.lower();
        if t not in valid_types: raise ValueError
        cmd = [self.ssh_keygen, '-t', t, '-N', '', '-f', dest]

        try:
            trace = open("/dev/null", "w")
        except EnvironmentError:
            raise service_error(service_error.internal,
                    "Cannot open /dev/null??");

        # May raise CalledProcessError
        self.log.debug("[generate_ssh_keys]: %s" % " ".join(cmd))
        rv = call(cmd, stdout=trace, stderr=trace, close_fds=True)
        if rv != 0:
            raise service_error(service_error.internal, 
                    "Cannot generate nonce ssh keys.  %s return code %d" \
                            % (self.ssh_keygen, rv))

    def gentopo(self, str):
        """
        Generate the topology dtat structure from the splitter's XML
        representation of it.

        The topology XML looks like:
            <experiment>
                <nodes>
                    <node><vname></vname><ips>ip1:ip2</ips></node>
                </nodes>
                <lans>
                    <lan>
                        <vname></vname><vnode></vnode><ip></ip>
                        <bandwidth></bandwidth><member>node:port</member>
                    </lan>
                </lans>
        """
        class topo_parse:
            """
            Parse the topology XML and create the dats structure.
            """
            def __init__(self):
                # Typing of the subelements for data conversion
                self.str_subelements = ('vname', 'vnode', 'ips', 'ip', 'member')
                self.int_subelements = ( 'bandwidth',)
                self.float_subelements = ( 'delay',)
                # The final data structure
                self.nodes = [ ]
                self.lans =  [ ]
                self.topo = { \
                        'node': self.nodes,\
                        'lan' : self.lans,\
                    }
                self.element = { }  # Current element being created
                self.chars = ""     # Last text seen

            def end_element(self, name):
                # After each sub element the contents is added to the current
                # element or to the appropriate list.
                if name == 'node':
                    self.nodes.append(self.element)
                    self.element = { }
                elif name == 'lan':
                    self.lans.append(self.element)
                    self.element = { }
                elif name in self.str_subelements:
                    self.element[name] = self.chars
                    self.chars = ""
                elif name in self.int_subelements:
                    self.element[name] = int(self.chars)
                    self.chars = ""
                elif name in self.float_subelements:
                    self.element[name] = float(self.chars)
                    self.chars = ""

            def found_chars(self, data):
                self.chars += data.rstrip()


        tp = topo_parse();
        parser = xml.parsers.expat.ParserCreate()
        parser.EndElementHandler = tp.end_element
        parser.CharacterDataHandler = tp.found_chars

        parser.Parse(str)

        return tp.topo
        

    def genviz(self, topo):
        """
        Generate the visualization the virtual topology
        """

        neato = "/usr/local/bin/neato"
        # These are used to parse neato output and to create the visualization
        # file.
        vis_re = re.compile('^\s*"?([\w\-]+)"?\s+\[.*pos="([\d\.]+),([\d\.]+)"')
        vis_fmt = "<node><name>%s</name><x>%s</x><y>%s</y><type>" + \
                "%s</type></node>"

        try:
            # Node names
            nodes = [ n['vname'] for n in topo['node'] ]
            topo_lans = topo['lan']
        except KeyError, e:
            raise service_error(service_error.internal, "Bad topology: %s" %e)

        lans = { }
        links = { }

        # Walk through the virtual topology, organizing the connections into
        # 2-node connections (links) and more-than-2-node connections (lans).
        # When a lan is created, it's added to the list of nodes (there's a
        # node in the visualization for the lan).
        for l in topo_lans:
            if links.has_key(l['vname']):
                if len(links[l['vname']]) < 2:
                    links[l['vname']].append(l['vnode'])
                else:
                    nodes.append(l['vname'])
                    lans[l['vname']] = links[l['vname']]
                    del links[l['vname']]
                    lans[l['vname']].append(l['vnode'])
            elif lans.has_key(l['vname']):
                lans[l['vname']].append(l['vnode'])
            else:
                links[l['vname']] = [ l['vnode'] ]


        # Open up a temporary file for dot to turn into a visualization
        try:
            df, dotname = tempfile.mkstemp()
            dotfile = os.fdopen(df, 'w')
        except EnvironmentError:
            raise service_error(service_error.internal,
                    "Failed to open file in genviz")

        try:
            dnull = open('/dev/null', 'w')
        except EnvironmentError:
            service_error(service_error.internal,
                    "Failed to open /dev/null in genviz")

        # Generate a dot/neato input file from the links, nodes and lans
        try:
            print >>dotfile, "graph G {"
            for n in nodes:
                print >>dotfile, '\t"%s"' % n
            for l in links.keys():
                print >>dotfile, '\t"%s" -- "%s"' %  tuple(links[l])
            for l in lans.keys():
                for n in lans[l]:
                    print >>dotfile, '\t "%s" -- "%s"' % (n,l)
            print >>dotfile, "}"
            dotfile.close()
        except TypeError:
            raise service_error(service_error.internal,
                    "Single endpoint link in vtopo")
        except EnvironmentError:
            raise service_error(service_error.internal, "Cannot write dot file")

        # Use dot to create a visualization
        dot = Popen([neato, '-Gstart=rand', '-Gepsilon=0.005', '-Gmaxiter=2000',
                '-Gpack=true', dotname], stdout=PIPE, stderr=dnull,
                close_fds=True)
        dnull.close()

        # Translate dot to vis format
        vis_nodes = [ ]
        vis = { 'node': vis_nodes }
        for line in dot.stdout:
            m = vis_re.match(line)
            if m:
                vn = m.group(1)
                vis_node = {'name': vn, \
                        'x': float(m.group(2)),\
                        'y' : float(m.group(3)),\
                    }
                if vn in links.keys() or vn in lans.keys():
                    vis_node['type'] = 'lan'
                else:
                    vis_node['type'] = 'node'
                vis_nodes.append(vis_node)
        rv = dot.wait()

        os.remove(dotname)
        if rv == 0 : return vis
        else: return None

    def get_access(self, tb, nodes, tbparam, access_user, masters):
        """
        Get access to testbed through fedd and set the parameters for that tb
        """
        def get_export_project(svcs):
            """
            Look through for the list of federated_service for this testbed
            objects for a project_export service, and extract the project
            parameter.
            """

            pe = [s for s in svcs if s.name=='project_export']
            if len(pe) == 1:
                return pe[0].params.get('project', None)
            elif len(pe) == 0:
                return None
            else:
                raise service_error(service_error.req,
                        "More than one project export is not supported")

        uri = self.tbmap.get(testbed_base(tb), None)
        if not uri:
            raise service_error(service_error.server_config, 
                    "Unknown testbed: %s" % tb)

        export_svcs = masters.get(tb,[])
        import_svcs = [ s for m in masters.values() \
                for s in m \
                    if tb in s.importers ]

        export_project = get_export_project(export_svcs)

        # Tweak search order so that if there are entries in access_user that 
        # have a project matching the export project, we try them first 
        if export_project: 
            access_sequence = [ (p, u) for p, u in access_user \
                    if p == export_project] 
            access_sequence.extend([(p, u) for p, u in access_user \
                    if p != export_project]) 
        else: 
            access_sequence = access_user 

        for p, u in access_sequence: 
            self.log.debug(("[get_access] Attempting access from (%s, %s) " + \
                    "to %s") %  ((p or "None"), u, uri))

            if p:
                # Request with user and project specified
                req = {\
                        'destinationTestbed' : { 'uri' : uri },
                        'credential': [ "project: %s" % p, "user: %s"  % u],
                        'allocID' : { 'localname': 'test' },
                    }
            else:
                # Request with only user specified
                req = {\
                        'destinationTestbed' : { 'uri' : uri },
                        'credential': [ 'user: %s' % u ],
                        'allocID' : { 'localname': 'test' },
                    }

            # Make the service request from the services we're importing and
            # exporting.  Keep track of the export request ids so we can
            # collect the resulting info from the access response.
            e_keys = { }
            if import_svcs or export_svcs:
                req['service'] = [ ]

                for i, s in enumerate(import_svcs):
                    idx = 'import%d' % i
                    sr = {'id': idx, 'name': s.name, 'visibility': 'import' }
                    if s.params:
                        sr['fedAttr'] = [ { 'attribute': k, 'value': v } \
                                for k, v in s.params.items()]
                    req['service'].append(sr)

                for i, s in enumerate(export_svcs):
                    idx = 'export%d' % i
                    e_keys[idx] = s
                    sr = {'id': idx, 'name': s.name, 'visibility': 'export' }
                    if s.params:
                        sr['fedAttr'] = [ { 'attribute': k, 'value': v } 
                                for k, v in s.params.items()]
                    req['service'].append(sr)

            # node resources if any
            if nodes != None and len(nodes) > 0:
                rnodes = [ ]
                for n in nodes:
                    rn = { }
                    image, hw, count = n.split(":")
                    if image: rn['image'] = [ image ]
                    if hw: rn['hardware'] = [ hw ]
                    if count and int(count) >0 : rn['count'] = int(count)
                    rnodes.append(rn)
                req['resources']= { }
                req['resources']['node'] = rnodes

            try:
                if self.local_access.has_key(uri):
                    # Local access call
                    req = { 'RequestAccessRequestBody' : req }
                    r = self.local_access[uri].RequestAccess(req, 
                            fedid(file=self.cert_file))
                    r = { 'RequestAccessResponseBody' : r }
                else:
                    r = self.call_RequestAccess(uri, req, 
                            self.cert_file, self.cert_pwd, self.trusted_certs)
            except service_error, e:
                if e.code == service_error.access:
                    self.log.debug("[get_access] Access denied")
                    r = None
                    continue
                else:
                    raise e

            if r.has_key('RequestAccessResponseBody'):
                # Through to here we have a valid response, not a fault.
                # Access denied is a fault, so something better or worse than
                # access denied has happened.
                r = r['RequestAccessResponseBody']
                self.log.debug("[get_access] Access granted")
                break
            else:
                raise service_error(service_error.protocol,
                        "Bad proxy response")
        
        if not r:
            raise service_error(service_error.access, 
                    "Access denied by %s (%s)" % (tb, uri))

        tbparam[tb] = { 
                "allocID" : r['allocID'],
                "uri": uri,
                }

        # Collect the responses corresponding to the services this testbed
        # exports.  These will be the service requests that we will include in
        # the start segment requests (with appropriate visibility values) to
        # import and export the segments.
        for s in r.get('service', []):
            id = s.get('id', None)
            if id and id in e_keys:
                e_keys[id].reqs.append(s)

        # Add attributes to parameter space.  We don't allow attributes to
        # overlay any parameters already installed.
        for a in r.get('fedAttr', []):
            try:
                if a['attribute'] and \
                        isinstance(a['attribute'], basestring)\
                        and not tbparam[tb].has_key(a['attribute'].lower()):
                    tbparam[tb][a['attribute'].lower()] = a['value']
            except KeyError:
                self.log.error("Bad attribute in response: %s" % a)

    def release_access(self, tb, aid, uri=None):
        """
        Release access to testbed through fedd
        """

        if not uri:
            uri = self.tbmap.get(tb, None)
        if not uri:
            raise service_error(service_error.server_config, 
                    "Unknown testbed: %s" % tb)

        if self.local_access.has_key(uri):
            resp = self.local_access[uri].ReleaseAccess(\
                    { 'ReleaseAccessRequestBody' : {'allocID': aid},}, 
                    fedid(file=self.cert_file))
            resp = { 'ReleaseAccessResponseBody': resp } 
        else:
            resp = self.call_ReleaseAccess(uri, {'allocID': aid},
                    self.cert_file, self.cert_pwd, self.trusted_certs)

        # better error coding

    def remote_ns2topdl(self, uri, desc):

        req = {
                'description' : { 'ns2description': desc },
            }

        r = self.call_Ns2Topdl(uri, req, self.cert_file, self.cert_pwd, 
                self.trusted_certs)

        if r.has_key('Ns2TopdlResponseBody'):
            r = r['Ns2TopdlResponseBody']
            ed = r.get('experimentdescription', None)
            if ed.has_key('topdldescription'):
                return topdl.Topology(**ed['topdldescription'])
            else:
                raise service_error(service_error.protocol, 
                        "Bad splitter response (no output)")
        else:
            raise service_error(service_error.protocol, "Bad splitter response")

    class start_segment:
        def __init__(self, debug=False, log=None, testbed="", cert_file=None,
                cert_pwd=None, trusted_certs=None, caller=None,
                log_collector=None):
            self.log = log
            self.debug = debug
            self.cert_file = cert_file
            self.cert_pwd = cert_pwd
            self.trusted_certs = None
            self.caller = caller
            self.testbed = testbed
            self.log_collector = log_collector
            self.response = None
            self.node = { }

        def make_map(self, resp):
            for e in resp.get('embedding', []):
                if 'toponame' in e and 'physname' in e:
                    self.node[e['toponame']] = e['physname'][0]

        def __call__(self, uri, aid, topo, masters, attrs=None, connInfo=None):
            req = {
                    'allocID': { 'fedid' : aid }, 
                    'segmentdescription': { 
                        'topdldescription': topo.to_dict(),
                    },
                }

            if connInfo:
                req['connection'] = connInfo

            import_svcs = [ s for m in masters.values() \
                    for s in m if self.testbed in s.importers]

            if import_svcs or self.testbed in masters:
                req['service'] = []

            for s in import_svcs:
                for r in s.reqs:
                    sr = copy.deepcopy(r)
                    sr['visibility'] = 'import';
                    req['service'].append(sr)

            for s in masters.get(self.testbed, []):
                for r in s.reqs:
                    sr = copy.deepcopy(r)
                    sr['visibility'] = 'export';
                    req['service'].append(sr)

            if attrs:
                req['fedAttr'] = attrs

            try:
                self.log.debug("Calling StartSegment at %s " % uri)
                r = self.caller(uri, req, self.cert_file, self.cert_pwd,
                        self.trusted_certs)
                if r.has_key('StartSegmentResponseBody'):
                    lval = r['StartSegmentResponseBody'].get('allocationLog',
                            None)
                    if lval and self.log_collector:
                        for line in  lval.splitlines(True):
                            self.log_collector.write(line)
                    self.make_map(r['StartSegmentResponseBody'])
                    self.response = r
                else:
                    raise service_error(service_error.internal, 
                            "Bad response!?: %s" %r)
                return True
            except service_error, e:
                self.log.error("Start segment failed on %s: %s" % \
                        (self.testbed, e))
                return False



    class terminate_segment:
        def __init__(self, debug=False, log=None, testbed="", cert_file=None,
                cert_pwd=None, trusted_certs=None, caller=None):
            self.log = log
            self.debug = debug
            self.cert_file = cert_file
            self.cert_pwd = cert_pwd
            self.trusted_certs = None
            self.caller = caller
            self.testbed = testbed

        def __call__(self, uri, aid ):
            req = {
                    'allocID': aid , 
                }
            try:
                r = self.caller(uri, req, self.cert_file, self.cert_pwd,
                        self.trusted_certs)
                return True
            except service_error, e:
                self.log.error("Terminate segment failed on %s: %s" % \
                        (self.testbed, e))
                return False
    

    def allocate_resources(self, allocated, masters, eid, expid, 
            tbparams, top, topo, tmpdir, alloc_log=None, log_collector=None, 
            attrs=None, connInfo={}):

        started = { }           # Testbeds where a sub-experiment started 
                                # successfully

        # XXX
        fail_soft = False

        log = alloc_log or self.log

        thread_pool = self.thread_pool(self.nthreads)
        threads = [ ]
        starters = [ ]

        for tb in allocated.keys():
            # Create and start a thread to start the segment, and save it
            # to get the return value later
            tb_attrs = copy.copy(attrs)
            thread_pool.wait_for_slot()
            uri = tbparams[tb].get('uri', \
                    self.tbmap.get(testbed_base(tb), None))
            base, suffix = split_testbed(tb)
            if suffix:
                tb_attrs.append({'attribute': 'experiment_name', 
                    'value': "%s-%s" % (eid, suffix)})
            else:
                tb_attrs.append({'attribute': 'experiment_name', 'value': eid})
            if not uri:
                raise service_error(service_error.internal, 
                        "Unknown testbed %s !?" % tb)

            if tbparams[tb].has_key('allocID') and \
                    tbparams[tb]['allocID'].has_key('fedid'):
                aid = tbparams[tb]['allocID']['fedid']
            else:
                raise service_error(service_error.internal, 
                        "No alloc id for testbed %s !?" % tb)

            s = self.start_segment(log=log, debug=self.debug,
                    testbed=tb, cert_file=self.cert_file,
                    cert_pwd=self.cert_pwd, trusted_certs=self.trusted_certs,
                    caller=self.call_StartSegment,
                    log_collector=log_collector)
            starters.append(s)
            t  = self.pooled_thread(\
                    target=s, name=tb,
                    args=(uri, aid, topo[tb], masters, tb_attrs, connInfo[tb]),
                    pdata=thread_pool, trace_file=self.trace_file)
            threads.append(t)
            t.start()

        # Wait until all finish (keep pinging the log, though)
        mins = 0
        revoked = False
        while not thread_pool.wait_for_all_done(60.0):
            mins += 1
            alloc_log.info("Waiting for sub threads (it has been %d mins)" \
                    % mins)
            if not revoked and \
                    len([ t.getName() for t in threads if t.rv == False]) > 0:
                # a testbed has failed.  Revoke this experiment's
                # synchronizarion values so that sub experiments will not
                # deadlock waiting for synchronization that will never happen
                self.log.info("A subexperiment has failed to swap in, " + \
                        "revoking synch keys")
                var_key = "fedid:%s" % expid
                for k in self.synch_store.all_keys():
                    if len(k) > 45 and k[0:46] == var_key:
                        self.synch_store.revoke_key(k)
                revoked = True

        failed = [ t.getName() for t in threads if not t.rv ]
        succeeded = [tb for tb in allocated.keys() if tb not in failed]

        # If one failed clean up, unless fail_soft is set
        if failed:
            if not fail_soft:
                thread_pool.clear()
                for tb in succeeded:
                    # Create and start a thread to stop the segment
                    thread_pool.wait_for_slot()
                    uri = tbparams[tb]['uri']
                    t  = self.pooled_thread(\
                            target=self.terminate_segment(log=log,
                                testbed=tb,
                                cert_file=self.cert_file, 
                                cert_pwd=self.cert_pwd,
                                trusted_certs=self.trusted_certs,
                                caller=self.call_TerminateSegment),
                            args=(uri, tbparams[tb]['federant']['allocID']),
                            name=tb,
                            pdata=thread_pool, trace_file=self.trace_file)
                    t.start()
                # Wait until all finish (if any are being stopped)
                if succeeded:
                    thread_pool.wait_for_all_done()

                # release the allocations
                for tb in tbparams.keys():
                    self.release_access(tb, tbparams[tb]['allocID'],
                            tbparams[tb].get('uri', None))
                # Remove the placeholder
                self.state_lock.acquire()
                self.state[eid]['experimentStatus'] = 'failed'
                if self.state_filename: self.write_state()
                self.state_lock.release()

                log.error("Swap in failed on %s" % ",".join(failed))
                return
        else:
            # Walk through the successes and gather the virtual to physical
            # mapping.
            embedding = [ ]
            for s in starters:
                for k, v in s.node.items():
                    embedding.append({
                        'toponame': k, 
                        'physname': [ v],
                        'testbed': s.testbed
                        })
            log.info("[start_segment]: Experiment %s active" % eid)


        # Walk up tmpdir, deleting as we go
        if self.cleanup:
            log.debug("[start_experiment]: removing %s" % tmpdir)
            for path, dirs, files in os.walk(tmpdir, topdown=False):
                for f in files:
                    os.remove(os.path.join(path, f))
                for d in dirs:
                    os.rmdir(os.path.join(path, d))
            os.rmdir(tmpdir)
        else:
            log.debug("[start_experiment]: not removing %s" % tmpdir)

        # Insert the experiment into our state and update the disk copy.
        self.state_lock.acquire()
        self.state[expid]['experimentStatus'] = 'active'
        self.state[eid] = self.state[expid]
        self.state[eid]['experimentdescription']['topdldescription'] = \
                top.to_dict()
        self.state[eid]['embedding'] = embedding
        if self.state_filename: self.write_state()
        self.state_lock.release()
        return


    def add_kit(self, e, kit):
        """
        Add a Software object created from the list of (install, location)
        tuples passed as kit  to the software attribute of an object e.  We
        do this enough to break out the code, but it's kind of a hack to
        avoid changing the old tuple rep.
        """

        s = [ topdl.Software(install=i, location=l) for i, l in kit]

        if isinstance(e.software, list): e.software.extend(s)
        else: e.software = s 


    def create_experiment_state(self, fid, req, expid, expcert,
            state='starting'):
        """
        Create the initial entry in the experiment's state.  The expid and
        expcert are the experiment's fedid and certifacte that represents that
        ID, which are installed in the experiment state.  If the request
        includes a suggested local name that is used if possible.  If the local
        name is already taken by an experiment owned by this user that has
        failed, it is overwritten.  Otherwise new letters are added until a
        valid localname is found.  The generated local name is returned.
        """

        if req.has_key('experimentID') and \
                req['experimentID'].has_key('localname'):
            overwrite = False
            eid = req['experimentID']['localname']
            # If there's an old failed experiment here with the same local name
            # and accessible by this user, we'll overwrite it, otherwise we'll
            # fall through and do the collision avoidance.
            old_expid = self.get_experiment_fedid(eid)
            if old_expid and self.check_experiment_access(fid, old_expid):
                self.state_lock.acquire()
                status = self.state[eid].get('experimentStatus', None)
                if status and status == 'failed':
                    # remove the old access attribute
                    self.auth.unset_attribute(fid, old_expid)
                    overwrite = True
                    del self.state[eid]
                    del self.state[old_expid]
                self.state_lock.release()
            self.state_lock.acquire()
            while (self.state.has_key(eid) and not overwrite):
                eid += random.choice(string.ascii_letters)
            # Initial state
            self.state[eid] = {
                    'experimentID' : \
                            [ { 'localname' : eid }, {'fedid': expid } ],
                    'experimentStatus': state,
                    'experimentAccess': { 'X509' : expcert },
                    'owner': fid,
                    'log' : [],
                }
            self.state[expid] = self.state[eid]
            if self.state_filename: self.write_state()
            self.state_lock.release()
        else:
            eid = self.exp_stem
            for i in range(0,5):
                eid += random.choice(string.ascii_letters)
            self.state_lock.acquire()
            while (self.state.has_key(eid)):
                eid = self.exp_stem
                for i in range(0,5):
                    eid += random.choice(string.ascii_letters)
            # Initial state
            self.state[eid] = {
                    'experimentID' : \
                            [ { 'localname' : eid }, {'fedid': expid } ],
                    'experimentStatus': state,
                    'experimentAccess': { 'X509' : expcert },
                    'owner': fid,
                    'log' : [],
                }
            self.state[expid] = self.state[eid]
            if self.state_filename: self.write_state()
            self.state_lock.release()

        return eid


    def allocate_ips_to_topo(self, top):
        """
        Add an ip4_address attribute to all the hosts in the topology, based on
        the shared substrates on which they sit.  An /etc/hosts file is also
        created and returned as a list of hostfiles entries.  We also return
        the allocator, because we may need to allocate IPs to portals
        (specifically DRAGON portals).
        """
        subs = sorted(top.substrates, 
                cmp=lambda x,y: cmp(len(x.interfaces), len(y.interfaces)),
                reverse=True)
        ips = ip_allocator(int(ip_addr("10.0.0.0")), 2 **24)
        ifs = { }
        hosts = [ ]

        for idx, s in enumerate(subs):
            net_size = len(s.interfaces)+2

            a = ips.allocate(net_size)
            if a :
                base, num = a
                if num < net_size: 
                    raise service_error(service_error.internal,
                            "Allocator returned wrong number of IPs??")
            else:
                raise service_error(service_error.req, 
                        "Cannot allocate IP addresses")
            mask = ips.min_alloc
            while mask < net_size:
                mask *= 2

            netmask = ((2**32-1) ^ (mask-1))

            base += 1
            for i in s.interfaces:
                i.attribute.append(
                        topdl.Attribute('ip4_address', 
                            "%s" % ip_addr(base)))
                i.attribute.append(
                        topdl.Attribute('ip4_netmask', 
                            "%s" % ip_addr(int(netmask))))

                hname = i.element.name
                if ifs.has_key(hname):
                    hosts.append("%s\t%s-%s %s-%d" % \
                            (ip_addr(base), hname, s.name, hname,
                                ifs[hname]))
                else:
                    ifs[hname] = 0
                    hosts.append("%s\t%s-%s %s-%d %s" % \
                            (ip_addr(base), hname, s.name, hname,
                                ifs[hname], hname))

                ifs[hname] += 1
                base += 1
        return hosts, ips

    def get_access_to_testbeds(self, testbeds, access_user, allocated, 
            tbparams, masters):
        """
        Request access to the various testbeds required for this instantiation
        (passed in as testbeds).  User, access_user, expoert_project and master
        are used to construct the correct requests.  Per-testbed parameters are
        returned in tbparams.
        """
        for tb in testbeds:
            self.get_access(tb, None, tbparams, access_user, masters)
            allocated[tb] = 1

    def split_topology(self, top, topo, testbeds):
        """
        Create the sub-topologies that are needed for experiment instantiation.
        """
        for tb in testbeds:
            topo[tb] = top.clone()
            # copy in for loop allows deletions from the original
            for e in [ e for e in topo[tb].elements]:
                etb = e.get_attribute('testbed')
                # NB: elements without a testbed attribute won't appear in any
                # sub topologies.  
                if not etb or etb != tb:
                    for i in e.interface:
                        for s in i.subs:
                            try:
                                s.interfaces.remove(i)
                            except ValueError:
                                raise service_error(service_error.internal,
                                        "Can't remove interface??")
                    topo[tb].elements.remove(e)
            topo[tb].make_indices()

    def wrangle_software(self, expid, top, topo, tbparams):
        """
        Copy software out to the repository directory, allocate permissions and
        rewrite the segment topologies to look for the software in local
        places.
        """

        # Copy the rpms and tarfiles to a distribution directory from
        # which the federants can retrieve them
        linkpath = "%s/software" %  expid
        softdir ="%s/%s" % ( self.repodir, linkpath)
        softmap = { }
        # These are in a list of tuples format (each kit).  This comprehension
        # unwraps them into a single list of tuples that initilaizes the set of
        # tuples.
        pkgs = set([ t for l in [self.fedkit, self.gatewaykit] \
                for p, t in l ])
        pkgs.update([x.location for e in top.elements \
                for x in e.software])
        try:
            os.makedirs(softdir)
        except EnvironmentError, e:
            raise service_error(
                    "Cannot create software directory: %s" % e)
        # The actual copying.  Everything's converted into a url for copying.
        for pkg in pkgs:
            loc = pkg

            scheme, host, path = urlparse(loc)[0:3]
            dest = os.path.basename(path)
            if not scheme:
                if not loc.startswith('/'):
                    loc = "/%s" % loc
                loc = "file://%s" %loc
            try:
                u = urlopen(loc)
            except Exception, e:
                raise service_error(service_error.req, 
                        "Cannot open %s: %s" % (loc, e))
            try:
                f = open("%s/%s" % (softdir, dest) , "w")
                self.log.debug("Writing %s/%s" % (softdir,dest) )
                data = u.read(4096)
                while data:
                    f.write(data)
                    data = u.read(4096)
                f.close()
                u.close()
            except Exception, e:
                raise service_error(service_error.internal,
                        "Could not copy %s: %s" % (loc, e))
            path = re.sub("/tmp", "", linkpath)
            # XXX
            softmap[pkg] = \
                    "%s/%s/%s" %\
                    ( self.repo_url, path, dest)

            # Allow the individual segments to access the software.
            for tb in tbparams.keys():
                self.auth.set_attribute(tbparams[tb]['allocID']['fedid'], 
                        "/%s/%s" % ( path, dest))

        # Convert the software locations in the segments into the local
        # copies on this host
        for soft in [ s for tb in topo.values() \
                for e in tb.elements \
                    if getattr(e, 'software', False) \
                        for s in e.software ]:
            if softmap.has_key(soft.location):
                soft.location = softmap[soft.location]


    def new_experiment(self, req, fid):
        """
        The external interface to empty initial experiment creation called from
        the dispatcher.

        Creates a working directory, splits the incoming description using the
        splitter script and parses out the avrious subsections using the
        lcasses above.  Once each sub-experiment is created, use pooled threads
        to instantiate them and start it all up.
        """
        if not self.auth.check_attribute(fid, 'new'):
            raise service_error(service_error.access, "New access denied")

        try:
            tmpdir = tempfile.mkdtemp(prefix="split-")
        except EnvironmentError:
            raise service_error(service_error.internal, "Cannot create tmp dir")

        try:
            access_user = self.accessdb[fid]
        except KeyError:
            raise service_error(service_error.internal,
                    "Access map and authorizer out of sync in " + \
                            "new_experiment for fedid %s"  % fid)

        pid = "dummy"
        gid = "dummy"

        req = req.get('NewRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no NewRequestBody)")

        # Generate an ID for the experiment (slice) and a certificate that the
        # allocator can use to prove they own it.  We'll ship it back through
        # the encrypted connection.
        (expid, expcert) = generate_fedid("test", dir=tmpdir, log=self.log)

        #now we're done with the tmpdir, and it should be empty
        if self.cleanup:
            self.log.debug("[new_experiment]: removing %s" % tmpdir)
            os.rmdir(tmpdir)
        else:
            self.log.debug("[new_experiment]: not removing %s" % tmpdir)

        eid = self.create_experiment_state(fid, req, expid, expcert, 
                state='empty')

        # Let users touch the state
        self.auth.set_attribute(fid, expid)
        self.auth.set_attribute(expid, expid)
        # Override fedids can manipulate state as well
        for o in self.overrides:
            self.auth.set_attribute(o, expid)

        rv = {
                'experimentID': [
                    {'localname' : eid }, { 'fedid': copy.copy(expid) }
                ],
                'experimentStatus': 'empty',
                'experimentAccess': { 'X509' : expcert }
            }

        return rv

    def create_experiment(self, req, fid):
        """
        The external interface to experiment creation called from the
        dispatcher.

        Creates a working directory, splits the incoming description using the
        splitter script and parses out the various subsections using the
        classes above.  Once each sub-experiment is created, use pooled threads
        to instantiate them and start it all up.
        """

        req = req.get('CreateRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no CreateRequestBody)")

        # Get the experiment access
        exp = req.get('experimentID', None)
        if exp:
            if exp.has_key('fedid'):
                key = exp['fedid']
                expid = key
                eid = None
            elif exp.has_key('localname'):
                key = exp['localname']
                eid = key
                expid = None
            else:
                raise service_error(service_error.req, "Unknown lookup type")
        else:
            raise service_error(service_error.req, "No request?")

        self.check_experiment_access(fid, key)

        try:
            tmpdir = tempfile.mkdtemp(prefix="split-")
            os.mkdir(tmpdir+"/keys")
        except EnvironmentError:
            raise service_error(service_error.internal, "Cannot create tmp dir")

        gw_pubkey_base = "fed.%s.pub" % self.ssh_type
        gw_secretkey_base = "fed.%s" % self.ssh_type
        gw_pubkey = tmpdir + "/keys/" + gw_pubkey_base
        gw_secretkey = tmpdir + "/keys/" + gw_secretkey_base
        tclfile = tmpdir + "/experiment.tcl"
        tbparams = { }
        try:
            access_user = self.accessdb[fid]
        except KeyError:
            raise service_error(service_error.internal,
                    "Access map and authorizer out of sync in " + \
                            "create_experiment for fedid %s"  % fid)

        pid = "dummy"
        gid = "dummy"

        # The tcl parser needs to read a file so put the content into that file
        descr=req.get('experimentdescription', None)
        if descr:
            file_content=descr.get('ns2description', None)
            if file_content:
                try:
                    f = open(tclfile, 'w')
                    f.write(file_content)
                    f.close()
                except EnvironmentError:
                    raise service_error(service_error.internal,
                            "Cannot write temp experiment description")
            else:
                raise service_error(service_error.req, 
                        "Only ns2descriptions supported")
        else:
            raise service_error(service_error.req, "No experiment description")

        self.state_lock.acquire()
        if self.state.has_key(key):
            self.state[key]['experimentStatus'] = "starting"
            for e in self.state[key].get('experimentID',[]):
                if not expid and e.has_key('fedid'):
                    expid = e['fedid']
                elif not eid and e.has_key('localname'):
                    eid = e['localname']
        self.state_lock.release()

        if not (eid and expid):
            raise service_error(service_error.internal, 
                    "Cannot find local experiment info!?")

        try: 
            # This catches exceptions to clear the placeholder if necessary
            try:
                self.generate_ssh_keys(gw_secretkey, self.ssh_type)
            except ValueError:
                raise service_error(service_error.server_config, 
                        "Bad key type (%s)" % self.ssh_type)

            # Copy the service request
            tb_services = [ s for s in req.get('service',[]) ]
            # Translate to topdl
            if self.splitter_url:
                self.log.debug("Calling remote topdl translator at %s" % \
                        self.splitter_url)
                top = self.remote_ns2topdl(self.splitter_url, file_content)
            else:
                tclcmd = [self.tclsh, self.tcl_splitter, '-t', '-x', 
                    str(self.muxmax), '-m', 'dummy']

                tclcmd.extend([pid, gid, eid, tclfile])

                self.log.debug("running local splitter %s", " ".join(tclcmd))
                # This is just fantastic.  As a side effect the parser copies
                # tb_compat.tcl into the current directory, so that directory
                # must be writable by the fedd user.  Doing this in the
                # temporary subdir ensures this is the case.
                tclparser = Popen(tclcmd, stdout=PIPE, close_fds=True, 
                        cwd=tmpdir)
                split_data = tclparser.stdout

                top = topdl.topology_from_xml(file=split_data, top="experiment")

            hosts, ip_allocator = self.allocate_ips_to_topo(top)
            # Find the testbeds to look up
            testbeds = set([ a.value for e in top.elements \
                    for a in e.attribute \
                        if a.attribute == 'testbed'])

            tb_hosts = { }
            for tb in testbeds:
                tb_hosts[tb] = [ e.name for e in top.elements \
                        if isinstance(e, topdl.Computer) and \
                            e.get_attribute('testbed') and \
                            e.get_attribute('testbed') == tb]

            masters = { }           # testbeds exporting services
            pmasters = { }          # Testbeds exporting services that 
                                    # need portals
            for s in tb_services:
                # If this is a service request with the importall field
                # set, fill it out.

                if s.get('importall', False):
                    s['import'] = [ tb for tb in testbeds \
                            if tb not in s.get('export',[])]
                    del s['importall']

                # Add the service to masters
                for tb in s.get('export', []):
                    if s.get('name', None):
                        if tb not in masters:
                            masters[tb] = [ ]

                        params = { }
                        if 'fedAttr' in s:
                            for a in s['fedAttr']:
                                params[a.get('attribute', '')] = \
                                        a.get('value','')

                        fser = federated_service(name=s['name'],
                                exporter=tb, importers=s.get('import',[]),
                                params=params)
                        if fser.name == 'hide_hosts' \
                                and 'hosts' not in fser.params:
                            fser.params['hosts'] = \
                                    ",".join(tb_hosts.get(fser.exporter, []))
                        masters[tb].append(fser)

                        if fser.portal:
                            if tb not in pmasters: pmasters[tb] = [ fser ]
                            else: pmasters[tb].append(fser)
                    else:
                        self.log.error('Testbed service does not have name " + \
                                "and importers')


            allocated = { }         # Testbeds we can access
            topo ={ }               # Sub topologies
            connInfo = { }          # Connection information

            self.get_access_to_testbeds(testbeds, access_user, allocated, 
                    tbparams, masters)

            self.split_topology(top, topo, testbeds)

            # Copy configuration files into the remote file store
            # The config urlpath
            configpath = "/%s/config" % expid
            # The config file system location
            configdir ="%s%s" % ( self.repodir, configpath)
            try:
                os.makedirs(configdir)
            except EnvironmentError, e:
                raise service_error(service_error.internal,
                        "Cannot create config directory: %s" % e)
            try:
                f = open("%s/hosts" % configdir, "w")
                f.write('\n'.join(hosts))
                f.close()
            except EnvironmentError, e:
                raise service_error(service_error.internal, 
                        "Cannot write hosts file: %s" % e)
            try:
                copy_file("%s" % gw_pubkey, "%s/%s" % \
                        (configdir, gw_pubkey_base))
                copy_file("%s" % gw_secretkey, "%s/%s" % \
                        (configdir, gw_secretkey_base))
            except EnvironmentError, e:
                raise service_error(service_error.internal, 
                        "Cannot copy keyfiles: %s" % e)

            # Allow the individual testbeds to access the configuration files.
            for tb in tbparams.keys():
                asignee = tbparams[tb]['allocID']['fedid']
                for f in ("hosts", gw_secretkey_base, gw_pubkey_base):
                    self.auth.set_attribute(asignee, "%s/%s" % (configpath, f))

            part = experiment_partition(self.auth, self.store_url, self.tbmap,
                    self.muxmax, self.direct_transit)
            part.add_portals(top, topo, eid, pmasters, tbparams, ip_allocator,
                    connInfo, expid)
            # Now get access to the dynamic testbeds (those added above)
            for tb in [ t for t in topo if t not in allocated]:
                self.get_access(tb, None, tbparams, access_user, masters)
                allocated[tb] = 1
                store_keys = topo[tb].get_attribute('store_keys')
                # Give the testbed access to keys it exports or imports
                if store_keys:
                    for sk in store_keys.split(" "):
                        self.auth.set_attribute(\
                                tbparams[tb]['allocID']['fedid'], sk)

            self.wrangle_software(expid, top, topo, tbparams)

            vtopo = topdl.topology_to_vtopo(top)
            vis = self.genviz(vtopo)

            # save federant information
            for k in allocated.keys():
                tbparams[k]['federant'] = {
                        'name': [ { 'localname' : eid} ],
                        'allocID' : tbparams[k]['allocID'],
                        'uri': tbparams[k]['uri'],
                    }

            self.state_lock.acquire()
            self.state[eid]['vtopo'] = vtopo
            self.state[eid]['vis'] = vis
            self.state[eid]['experimentdescription'] = \
                    { 'topdldescription': top.to_dict() }
            self.state[eid]['federant'] = \
                    [ tbparams[tb]['federant'] for tb in tbparams.keys() \
                        if tbparams[tb].has_key('federant') ]
            if self.state_filename: 
                self.write_state()
            self.state_lock.release()
        except service_error, e:
            # If something goes wrong in the parse (usually an access error)
            # clear the placeholder state.  From here on out the code delays
            # exceptions.  Failing at this point returns a fault to the remote
            # caller. 

            self.state_lock.acquire()
            del self.state[eid]
            del self.state[expid]
            if self.state_filename: self.write_state()
            self.state_lock.release()
            raise e


        # Start the background swapper and return the starting state.  From
        # here on out, the state will stick around a while.

        # Let users touch the state
        self.auth.set_attribute(fid, expid)
        self.auth.set_attribute(expid, expid)
        # Override fedids can manipulate state as well
        for o in self.overrides:
            self.auth.set_attribute(o, expid)

        # Create a logger that logs to the experiment's state object as well as
        # to the main log file.
        alloc_log = logging.getLogger('fedd.experiment_control.%s' % eid)
        alloc_collector = self.list_log(self.state[eid]['log'])
        h = logging.StreamHandler(alloc_collector)
        # XXX: there should be a global one of these rather than repeating the
        # code.
        h.setFormatter(logging.Formatter("%(asctime)s %(name)s %(message)s",
                    '%d %b %y %H:%M:%S'))
        alloc_log.addHandler(h)
        
        attrs = [ 
                {
                    'attribute': 'ssh_pubkey', 
                    'value': '%s/%s/config/%s' % \
                            (self.repo_url, expid, gw_pubkey_base)
                },
                {
                    'attribute': 'ssh_secretkey', 
                    'value': '%s/%s/config/%s' % \
                            (self.repo_url, expid, gw_secretkey_base)
                },
                {
                    'attribute': 'hosts', 
                    'value': '%s/%s/config/hosts' % \
                            (self.repo_url, expid)
                },
            ]

        # transit and disconnected testbeds may not have a connInfo entry.
        # Fill in the blanks.
        for t in allocated.keys():
            if not connInfo.has_key(t):
                connInfo[t] = { }

        # Start a thread to do the resource allocation
        t  = Thread(target=self.allocate_resources,
                args=(allocated, masters, eid, expid, tbparams, 
                    top, topo, tmpdir, alloc_log, alloc_collector, attrs,
                    connInfo),
                name=eid)
        t.start()

        rv = {
                'experimentID': [
                    {'localname' : eid }, { 'fedid': copy.copy(expid) }
                ],
                'experimentStatus': 'starting',
            }

        return rv
    
    def get_experiment_fedid(self, key):
        """
        find the fedid associated with the localname key in the state database.
        """

        rv = None
        self.state_lock.acquire()
        if self.state.has_key(key):
            if isinstance(self.state[key], dict):
                try:
                    kl = [ f['fedid'] for f in \
                            self.state[key]['experimentID']\
                                if f.has_key('fedid') ]
                except KeyError:
                    self.state_lock.release()
                    raise service_error(service_error.internal, 
                            "No fedid for experiment %s when getting "+\
                                    "fedid(!?)" % key)
                if len(kl) == 1:
                    rv = kl[0]
                else:
                    self.state_lock.release()
                    raise service_error(service_error.internal, 
                            "multiple fedids for experiment %s when " +\
                                    "getting fedid(!?)" % key)
            else:
                self.state_lock.release()
                raise service_error(service_error.internal, 
                        "Unexpected state for %s" % key)
        self.state_lock.release()
        return rv

    def check_experiment_access(self, fid, key):
        """
        Confirm that the fid has access to the experiment.  Though a request
        may be made in terms of a local name, the access attribute is always
        the experiment's fedid.
        """
        if not isinstance(key, fedid):
            key = self.get_experiment_fedid(key)

        if self.auth.check_attribute(fid, key):
            return True
        else:
            raise service_error(service_error.access, "Access Denied")


    def get_handler(self, path, fid):
        self.log.info("Get handler %s %s" % (path, fid))
        if self.auth.check_attribute(fid, path):
            return ("%s/%s" % (self.repodir, path), "application/binary")
        else:
            return (None, None)

    def get_vtopo(self, req, fid):
        """
        Return the stored virtual topology for this experiment
        """
        rv = None
        state = None

        req = req.get('VtopoRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no VtopoRequestBody)")
        exp = req.get('experiment', None)
        if exp:
            if exp.has_key('fedid'):
                key = exp['fedid']
                keytype = "fedid"
            elif exp.has_key('localname'):
                key = exp['localname']
                keytype = "localname"
            else:
                raise service_error(service_error.req, "Unknown lookup type")
        else:
            raise service_error(service_error.req, "No request?")

        self.check_experiment_access(fid, key)

        self.state_lock.acquire()
        if self.state.has_key(key):
            if self.state[key].has_key('vtopo'):
                rv = { 'experiment' : {keytype: key },\
                        'vtopo': self.state[key]['vtopo'],\
                    }
            else:
                state = self.state[key]['experimentStatus']
        self.state_lock.release()

        if rv: return rv
        else: 
            if state:
                raise service_error(service_error.partial, 
                        "Not ready: %s" % state)
            else:
                raise service_error(service_error.req, "No such experiment")

    def get_vis(self, req, fid):
        """
        Return the stored visualization for this experiment
        """
        rv = None
        state = None

        req = req.get('VisRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no VisRequestBody)")
        exp = req.get('experiment', None)
        if exp:
            if exp.has_key('fedid'):
                key = exp['fedid']
                keytype = "fedid"
            elif exp.has_key('localname'):
                key = exp['localname']
                keytype = "localname"
            else:
                raise service_error(service_error.req, "Unknown lookup type")
        else:
            raise service_error(service_error.req, "No request?")

        self.check_experiment_access(fid, key)

        self.state_lock.acquire()
        if self.state.has_key(key):
            if self.state[key].has_key('vis'):
                rv =  { 'experiment' : {keytype: key },\
                        'vis': self.state[key]['vis'],\
                        }
            else:
                state = self.state[key]['experimentStatus']
        self.state_lock.release()

        if rv: return rv
        else:
            if state:
                raise service_error(service_error.partial, 
                        "Not ready: %s" % state)
            else:
                raise service_error(service_error.req, "No such experiment")

    def clean_info_response(self, rv):
        """
        Remove the information in the experiment's state object that is not in
        the info response.
        """
        # Remove the owner info (should always be there, but...)
        if rv.has_key('owner'): del rv['owner']

        # Convert the log into the allocationLog parameter and remove the
        # log entry (with defensive programming)
        if rv.has_key('log'):
            rv['allocationLog'] = "".join(rv['log'])
            del rv['log']
        else:
            rv['allocationLog'] = ""

        if rv['experimentStatus'] != 'active':
            if rv.has_key('federant'): del rv['federant']
        else:
            # remove the allocationID and uri info from each federant
            for f in rv.get('federant', []):
                if f.has_key('allocID'): del f['allocID']
                if f.has_key('uri'): del f['uri']

        return rv

    def get_info(self, req, fid):
        """
        Return all the stored info about this experiment
        """
        rv = None

        req = req.get('InfoRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no InfoRequestBody)")
        exp = req.get('experiment', None)
        if exp:
            if exp.has_key('fedid'):
                key = exp['fedid']
                keytype = "fedid"
            elif exp.has_key('localname'):
                key = exp['localname']
                keytype = "localname"
            else:
                raise service_error(service_error.req, "Unknown lookup type")
        else:
            raise service_error(service_error.req, "No request?")

        self.check_experiment_access(fid, key)

        # The state may be massaged by the service function that called
        # get_info (e.g., encoded for XMLRPC transport) so send a copy of the
        # state.
        self.state_lock.acquire()
        if self.state.has_key(key):
            rv = copy.deepcopy(self.state[key])
        self.state_lock.release()

        if rv:
            return self.clean_info_response(rv)
        else:
            raise service_error(service_error.req, "No such experiment")

    def get_multi_info(self, req, fid):
        """
        Return all the stored info that this fedid can access
        """
        rv = { 'info': [ ] }

        self.state_lock.acquire()
        for key in [ k for k in self.state.keys() if isinstance(k, fedid)]:
            try:
                self.check_experiment_access(fid, key)
            except service_error, e:
                if e.code == service_error.access:
                    continue
                else:
                    self.state_lock.release()
                    raise e

            if self.state.has_key(key):
                e = copy.deepcopy(self.state[key])
                e = self.clean_info_response(e)
                rv['info'].append(e)
        self.state_lock.release()
        return rv

    def remove_dirs(self, dir):
        """
        Remove the directory tree and all files rooted at dir.  Log any errors,
        but continue.
        """
        self.log.debug("[removedirs]: removing %s" % dir)
        try:
            for path, dirs, files in os.walk(dir, topdown=False):
                for f in files:
                    os.remove(os.path.join(path, f))
                for d in dirs:
                    os.rmdir(os.path.join(path, d))
            os.rmdir(dir)
        except EnvironmentError, e:
            self.log.error("Error deleting directory tree in %s" % e);

    def terminate_experiment(self, req, fid):
        """
        Swap this experiment out on the federants and delete the shared
        information
        """
        tbparams = { }
        req = req.get('TerminateRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no TerminateRequestBody)")
        force = req.get('force', False)
        exp = req.get('experiment', None)
        if exp:
            if exp.has_key('fedid'):
                key = exp['fedid']
                keytype = "fedid"
            elif exp.has_key('localname'):
                key = exp['localname']
                keytype = "localname"
            else:
                raise service_error(service_error.req, "Unknown lookup type")
        else:
            raise service_error(service_error.req, "No request?")

        self.check_experiment_access(fid, key)

        dealloc_list = [ ]


        # Create a logger that logs to the dealloc_list as well as to the main
        # log file.
        dealloc_log = logging.getLogger('fedd.experiment_control.%s' % key)
        h = logging.StreamHandler(self.list_log(dealloc_list))
        # XXX: there should be a global one of these rather than repeating the
        # code.
        h.setFormatter(logging.Formatter("%(asctime)s %(name)s %(message)s",
                    '%d %b %y %H:%M:%S'))
        dealloc_log.addHandler(h)

        self.state_lock.acquire()
        fed_exp = self.state.get(key, None)
        repo = None

        if fed_exp:
            # This branch of the conditional holds the lock to generate a
            # consistent temporary tbparams variable to deallocate experiments.
            # It releases the lock to do the deallocations and reacquires it to
            # remove the experiment state when the termination is complete.

            # First make sure that the experiment creation is complete.
            status = fed_exp.get('experimentStatus', None)

            if status:
                if status in ('starting', 'terminating'):
                    if not force:
                        self.state_lock.release()
                        raise service_error(service_error.partial, 
                                'Experiment still being created or destroyed')
                    else:
                        self.log.warning('Experiment in %s state ' % status + \
                                'being terminated by force.')
            else:
                # No status??? trouble
                self.state_lock.release()
                raise service_error(service_error.internal,
                        "Experiment has no status!?")

            ids = []
            #  experimentID is a list of dicts that are self-describing
            #  identifiers.  This finds all the fedids and localnames - the
            #  keys of self.state - and puts them into ids.
            for id in fed_exp.get('experimentID', []):
                if id.has_key('fedid'): 
                    ids.append(id['fedid'])
                    repo = "%s" % id['fedid']
                if id.has_key('localname'): ids.append(id['localname'])

            # Collect the allocation/segment ids into a dict keyed by the fedid
            # of the allocation (or a monotonically increasing integer) that
            # contains a tuple of uri, aid (which is a dict...)
            for i, fed in enumerate(fed_exp.get('federant', [])):
                try:
                    uri = fed['uri']
                    aid = fed['allocID']
                    k = fed['allocID'].get('fedid', i)
                except KeyError, e:
                    continue
                tbparams[k] = (uri, aid)
            fed_exp['experimentStatus'] = 'terminating'
            if self.state_filename: self.write_state()
            self.state_lock.release()

            # Stop everyone.  NB, wait_for_all waits until a thread starts and
            # then completes, so we can't wait if nothing starts.  So, no
            # tbparams, no start.
            if len(tbparams) > 0:
                thread_pool = self.thread_pool(self.nthreads)
                for k in tbparams.keys():
                    # Create and start a thread to stop the segment
                    thread_pool.wait_for_slot()
                    uri, aid = tbparams[k]
                    t  = self.pooled_thread(\
                            target=self.terminate_segment(log=dealloc_log,
                                testbed=uri,
                                cert_file=self.cert_file, 
                                cert_pwd=self.cert_pwd,
                                trusted_certs=self.trusted_certs,
                                caller=self.call_TerminateSegment),
                            args=(uri, aid), name=k,
                            pdata=thread_pool, trace_file=self.trace_file)
                    t.start()
                # Wait for completions
                thread_pool.wait_for_all_done()

            # release the allocations (failed experiments have done this
            # already, and starting experiments may be in odd states, so we
            # ignore errors releasing those allocations
            try: 
                for k in tbparams.keys():
                    # This releases access by uri
                    uri, aid = tbparams[k]
                    self.release_access(None, aid, uri=uri)
            except service_error, e:
                if status != 'failed' and not force:
                    raise e

            # Remove the terminated experiment
            self.state_lock.acquire()
            for id in ids:
                if self.state.has_key(id): del self.state[id]

            if self.state_filename: self.write_state()
            self.state_lock.release()

            # Delete any synch points associated with this experiment.  All
            # synch points begin with the fedid of the experiment.
            fedid_keys = set(["fedid:%s" % f for f in ids \
                    if isinstance(f, fedid)])
            for k in self.synch_store.all_keys():
                try:
                    if len(k) > 45 and k[0:46] in fedid_keys:
                        self.synch_store.del_value(k)
                except synch_store.BadDeletionError:
                    pass
            self.write_store()

            # Remove software and other cached stuff from the filesystem.
            if repo:
                self.remove_dirs("%s/%s" % (self.repodir, repo))
                
            return { 
                    'experiment': exp , 
                    'deallocationLog': "".join(dealloc_list),
                    }
        else:
            # Don't forget to release the lock
            self.state_lock.release()
            raise service_error(service_error.req, "No saved state")


    def GetValue(self, req, fid):
        """
        Get a value from the synchronized store
        """
        req = req.get('GetValueRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no GetValueRequestBody)")
        
        name = req['name']
        wait = req['wait']
        rv = { 'name': name }

        if self.auth.check_attribute(fid, name):
            self.log.debug("[GetValue] asking for %s " % name)
            try:
                v = self.synch_store.get_value(name, wait)
            except synch_store.RevokedKeyError:
                # No more synch on this key
                raise service_error(service_error.federant, 
                        "Synch key %s revoked" % name)
            if v is not None:
                rv['value'] = v
            self.log.debug("[GetValue] got %s from %s" % (v, name))
            return rv
        else:
            raise service_error(service_error.access, "Access Denied")
        

    def SetValue(self, req, fid):
        """
        Set a value in the synchronized store
        """
        req = req.get('SetValueRequestBody', None)
        if not req:
            raise service_error(service_error.req,
                    "Bad request format (no SetValueRequestBody)")
        
        name = req['name']
        v = req['value']

        if self.auth.check_attribute(fid, name):
            try:
                self.synch_store.set_value(name, v)
                self.write_store()
                self.log.debug("[SetValue] set %s to %s" % (name, v))
            except synch_store.CollisionError:
                # Translate into a service_error
                raise service_error(service_error.req,
                        "Value already set: %s" %name)
            except synch_store.RevokedKeyError:
                # No more synch on this key
                raise service_error(service_error.federant, 
                        "Synch key %s revoked" % name)
            return { 'name': name, 'value': v }
        else:
            raise service_error(service_error.access, "Access Denied")