source: fedd/federation/emulab_shared_nat_segment.py @ a80a4a7

#!/usr/local/bin/python

import sys, os
import re
import os.path

import tempfile
import subprocess
import logging 
import time
import signal

import util

import xmlrpclib

import emulab_segment


class start_segment(emulab_segment.start_segment):
    def __init__(self, log=None, keyfile=None, debug=False, boss=None,
            ops=None, cert=None):
        emulab_segment.start_segment.__init__(self, log=log, keyfile=keyfile,
                debug=debug, boss=boss, ops=ops, cert=cert)

    def __call__(self, parent, eid, pid, user, tclfile, tmpdir, timeout=0, 
            gid=None):
        """
        Start a sub-experiment on a federant.

        Get the current state, and terminate the experiment if it exists. The
        group membership of the experiment is difficult to determine or change,
        so start with a clean slate.  Create a new one and ship data
        and configs and start the experiment.  There are small ordering
        differences based on the initial state of the sub-experiment.
        """

        # exports_segment has established a clean dummy experiment.

        if not self.set_up_experiment_filespace(user, self.ops, 
                pid, eid, tmpdir):
            return False

        # Put the file into a string to pass to emulab.
        try:
            tcl = "".join([ l for l in open(tclfile,"r")])
        except EnvironmentError, e:
            self.log.error("Can't read %s: %s" % (tclfile, e))
            return False
        
        # Stage the new configuration
        if not self.modify_exp(pid, eid, tcl):
            self.log.error("modify failed")
            return False

        if not self.swap_exp(pid, eid, 'in'):
            self.log.error("swap in failed")
            return False
        # Everything has gone OK.
        self.get_mapping(pid,eid)
        return True

class exports_segment(emulab_segment.exports_segment):
    '''
    Class to export parameters from this segment.  The shared NAT allocates
    externally accessible ports in 2 steps.  Provisional ports are assigned
    when the experiment is created or modified and then preserved when possible
    across further mods.  This class creates a very simple experiment to make
    those provisional allocations and then installs them in the connInfo list.
    Note that this class takes on some of the initial steps from start_segment
    - clearing out old experiments and creating the dummy and initial
    experiment.
    '''
    def __init__(self, log=None, keyfile=None, debug=False, boss=None,
            ops=None, cert=None):
        emulab_segment.exports_segment.__init__(self, log=log, keyfile=keyfile,
                debug=debug, boss=boss, ops=ops, cert=cert)

    def make_portal_experiment(self, pid, eid, tmpdir, gid, ports):
        ns_data = \
'''
set ns [new Simulator]
source tb_compat.tcl

'''
        for p in ports:
            ns_data += 'set %s [$ns node]\n' % p
            ns_data += \
                'tb-allow-external %s shared nat 0/0/tcp rdr 22/tcp\n' % p
        ns_data += \
'''     
$ns rtproto Session
$ns run 
'''
        # If ports is empty, just create the standard null experiment
        if len(ports) == 0:
            ns_data = None

        state = self.get_state(pid, eid)

        if state != 'none':
            self.terminate_exp(pid, eid)

        return self.make_null_experiment(pid, eid, tmpdir, gid, ns_data)

    def get_assignments(self, pid, eid, user, tmpdir, ports):
        '''
        Copy the output of the shared NAT risky experiment setup output to the
        temporary directory and parse it for preliminary (and hopefully
        permanent) port assignments.  That output is a pseudo-xmlrpc response.
        '''
        # No ports? Nothing to do here.
        if len(ports) == 0:
            return True

        remote_risk = os.path.join('/proj', pid, 'exp', eid, 'tbdata',
                '%s.risk' % eid)
        local_risk = os.path.join(tmpdir, 'risk')

        try:
            self.scp_file_from(remote_risk, user, self.ops, local_risk)
            f = open(local_risk)
            params, method = xmlrpclib.loads(f.read())
            f.close()
            # params should be a single element tuple containing the "xmlrpc"
            # request as a dict
            if not isinstance(params, tuple):
                self.log.error('misformatted risk file: params not a tuple')
                return False
            params = params[0]

            if 'assignments' not in params:
                self.log.error('misformatted risk file: No arguments in params')
                return False

            for k, v in params['assignments'].items():
                if not k.endswith('/22/tcp'):
                    continue
                # Get the portal name from the SSH port assignment
                p = k[0:k.index('/22/tcp')]
                if p in ports:
                    ports[p]  = v
        except Exception, e:
            self.log.error('Error getting assignments: %s' % e)
            return False
        return True


    def __call__(self, parent, eid, pid, user, connInfo, tmpdir, timeout=0,
            gid=None):
        '''
        Create an experiment containing only portals and read the ssh_ports
        from it.  The shared NAT properly marshals DNS names.
        '''

        ports = { }

        for c in connInfo:
            for p in c.get('parameter', []):
                # Only set output parameters
                if  p.get('type', '') != 'output':
                    continue
                name = p.get('name', '')
                k = p.get('key', None)
                if name == 'peer':
                    if k is None or k.index('/') == -1:
                        self.log.debug('Bad key for peer: %s' % k)
                        return False

                    portal_name = k[k.index('/')+1:]

                    if parent.nat_portal:
                        value = parent.nat_portal
                    elif k and k.index('/') != -1:
                        value = "%s.%s.%s%s" % \
                            (portal_name, eid, pid, parent.domain)
                    else:
                        self.log.error('Bad export request: %s' % p)
                        continue
                    p['value'] = value
                    ports[portal_name] = None
                    self.log.debug('Assigning %s to %s' % (k, value))
                    self.log.debug('Adding entry for %s to ports' % portal_name)
                elif name == 'ssh_port':
                    # not yet
                    continue
                else:
                    self.log.error("Unknown export parameter: %s" % name)
                    return False

        if not self.make_portal_experiment(pid, eid, tmpdir, gid, ports):
            return False

        if not self.get_assignments(pid, eid, user, tmpdir, ports):
            return False

        # Through these again to set ssh_ports
        for c in connInfo:
            for p in c.get('parameter', []):
                # Only set output parameters
                if  p.get('type', '') != 'output':
                    continue
                name = p.get('name', '')
                k = p.get('key', None)
                if name != 'ssh_port':
                    continue
                if k is None or k.index('/') == -1:
                    self.log.debug('Bad key for ssh port: %s' % k)
                    return False

                # The portal name is the string following the slash in the key,
                # with the trainling (5 character) -port removed.
                portal_name = k[k.index('/')+1:-5]
                if portal_name not in ports or ports[portal_name] is None:
                    self.log.error('No port assigned to %s' % portal_name)
                    return False
                value = ports[portal_name]
                p['value'] = value
                self.log.debug('Assigning %s to %s' % (k, value))
        
        return True

# These are all simple aliases to the main emulab_segment line.
class stop_segment(emulab_segment.stop_segment):
    def __init__(self, log=None, keyfile=None, debug=False, boss=None, 
            ops=None, cert=None):
        emulab_segment.stop_segment.__init__(self, log=log, keyfile=keyfile,
                debug=debug, boss=boss, ops=ops, cert=cert)

class info_segment(emulab_segment.info_segment):
    def __init__(self, log=None, keyfile=None, debug=False, boss=None, 
            ops=None, cert=None):
        emulab_segment.info_segment.__init__(self, log=log, keyfile=keyfile,
                debug=debug, boss=boss, ops=ops, cert=cert)

class operation_segment(emulab_segment.operation_segment):
    def __init__(self, log=None, keyfile=None, debug=False, boss=None, 
            ops=None, cert=None):
        emulab_segment.operation_segment.__init__(self, log=log,
                keyfile=keyfile, debug=debug, boss=boss, ops=ops, cert=cert)