sfa/planetlab/plslices.py

   1 from types import StringTypes
   2 from collections import defaultdict
   3 import sys
   4
   5 from sfa.util.sfatime import utcparse, datetime_to_epoch
   6 from sfa.util.sfalogging import logger
   7 from sfa.util.xrn import Xrn, get_leaf, get_authority, urn_to_hrn
   8
   9 from sfa.rspecs.rspec import RSpec
  10
  11 from sfa.planetlab.vlink import VLink
  12 from sfa.planetlab.plxrn import PlXrn, hrn_to_pl_slicename
  13
  14 MAXINT =  2L**31-1
  15
  16 class PlSlices:
  17
  18     rspec_to_slice_tag = {'max_rate':'net_max_rate'}
  19
  20     def __init__(self, driver):
  21         self.driver = driver
  22
  23     def get_slivers(self, xrn, node=None):
  24         hrn, type = urn_to_hrn(xrn)
  25
  26         slice_name = hrn_to_pl_slicename(hrn)
  27         # XX Should we just call PLCAPI.GetSliceTicket(slice_name) instead
  28         # of doing all of this?
  29         #return self.driver.shell.GetSliceTicket(self.auth, slice_name)
  30
  31         # from PLCAPI.GetSlivers.get_slivers()
  32         slice_fields = ['slice_id', 'name', 'instantiation', 'expires', 'person_ids', 'slice_tag_ids']
  33         slices = self.driver.shell.GetSlices(slice_name, slice_fields)
  34         # Build up list of users and slice attributes
  35         person_ids = set()
  36         all_slice_tag_ids = set()
  37         for slice in slices:
  38             person_ids.update(slice['person_ids'])
  39             all_slice_tag_ids.update(slice['slice_tag_ids'])
  40         person_ids = list(person_ids)
  41         all_slice_tag_ids = list(all_slice_tag_ids)
  42         # Get user information
  43         all_persons_list = self.driver.shell.GetPersons({'person_id':person_ids,'enabled':True}, ['person_id', 'enabled', 'key_ids'])
  44         all_persons = {}
  45         for person in all_persons_list:
  46             all_persons[person['person_id']] = person
  47
  48         # Build up list of keys
  49         key_ids = set()
  50         for person in all_persons.values():
  51             key_ids.update(person['key_ids'])
  52         key_ids = list(key_ids)
  53         # Get user account keys
  54         all_keys_list = self.driver.shell.GetKeys(key_ids, ['key_id', 'key', 'key_type'])
  55         all_keys = {}
  56         for key in all_keys_list:
  57             all_keys[key['key_id']] = key
  58         # Get slice attributes
  59         all_slice_tags_list = self.driver.shell.GetSliceTags(all_slice_tag_ids)
  60         all_slice_tags = {}
  61         for slice_tag in all_slice_tags_list:
  62             all_slice_tags[slice_tag['slice_tag_id']] = slice_tag
  63
  64         slivers = []
  65         for slice in slices:
  66             keys = []
  67             for person_id in slice['person_ids']:
  68                 if person_id in all_persons:
  69                     person = all_persons[person_id]
  70                     if not person['enabled']:
  71                         continue
  72                     for key_id in person['key_ids']:
  73                         if key_id in all_keys:
  74                             key = all_keys[key_id]
  75                             keys += [{'key_type': key['key_type'],
  76                                     'key': key['key']}]
  77             attributes = []
  78             # All (per-node and global) attributes for this slice
  79             slice_tags = []
  80             for slice_tag_id in slice['slice_tag_ids']:
  81                 if slice_tag_id in all_slice_tags:
  82                     slice_tags.append(all_slice_tags[slice_tag_id])
  83             # Per-node sliver attributes take precedence over global
  84             # slice attributes, so set them first.
  85             # Then comes nodegroup slice attributes
  86             # Followed by global slice attributes
  87             sliver_attributes = []
  88
  89             if node is not None:
  90                 for sliver_attribute in filter(lambda a: a['node_id'] == node['node_id'], slice_tags):
  91                     sliver_attributes.append(sliver_attribute['tagname'])
  92                     attributes.append({'tagname': sliver_attribute['tagname'],
  93                                     'value': sliver_attribute['value']})
  94
  95             # set nodegroup slice attributes
  96             for slice_tag in filter(lambda a: a['nodegroup_id'] in node['nodegroup_ids'], slice_tags):
  97                 # Do not set any nodegroup slice attributes for
  98                 # which there is at least one sliver attribute
  99                 # already set.
 100                 if slice_tag not in slice_tags:
 101                     attributes.append({'tagname': slice_tag['tagname'],
 102                         'value': slice_tag['value']})
 103
 104             for slice_tag in filter(lambda a: a['node_id'] is None, slice_tags):
 105                 # Do not set any global slice attributes for
 106                 # which there is at least one sliver attribute
 107                 # already set.
 108                 if slice_tag['tagname'] not in sliver_attributes:
 109                     attributes.append({'tagname': slice_tag['tagname'],
 110                                    'value': slice_tag['value']})
 111
 112             # XXX Sanity check; though technically this should be a system invariant
 113             # checked with an assertion
 114             if slice['expires'] > MAXINT:  slice['expires']= MAXINT
 115
 116             slivers.append({
 117                 'hrn': hrn,
 118                 'name': slice['name'],
 119                 'slice_id': slice['slice_id'],
 120                 'instantiation': slice['instantiation'],
 121                 'expires': slice['expires'],
 122                 'keys': keys,
 123                 'attributes': attributes
 124             })
 125
 126         return slivers
 127
 128     def get_peer(self, xrn):
 129         hrn, type = urn_to_hrn(xrn)
 130         # Becaues of myplc federation,  we first need to determine if this
 131         # slice belongs to out local plc or a myplc peer. We will assume it
 132         # is a local site, unless we find out otherwise
 133         peer = None
 134         # get this slice's authority (site)
 135         slice_authority = get_authority(hrn)
 136
 137         # get this site's authority (sfa root authority or sub authority)
 138         site_authority = get_authority(slice_authority).lower()
 139         # check if we are already peered with this site_authority, if so
 140         peers = self.driver.shell.GetPeers({}, ['peer_id', 'peername', 'shortname', 'hrn_root'])
 141         for peer_record in peers:
 142             names = [name.lower() for name in peer_record.values() if isinstance(name, StringTypes)]
 143             if site_authority in names:
 144                 peer = peer_record
 145
 146         return peer
 147
 148     def get_sfa_peer(self, xrn):
 149         hrn, type = urn_to_hrn(xrn)
 150
 151         # return the authority for this hrn or None if we are the authority
 152         sfa_peer = None
 153         slice_authority = get_authority(hrn)
 154         site_authority = get_authority(slice_authority)
 155
 156         if site_authority != self.driver.hrn:
 157             sfa_peer = site_authority
 158
 159         return sfa_peer
 160
 161     def verify_slice_leases(self, slice, requested_leases, kept_leases, peer):
 162
 163         leases = self.driver.shell.GetLeases({'name':slice['name']}, ['lease_id'])
 164         grain = self.driver.shell.GetLeaseGranularity()
 165         current_leases = [lease['lease_id'] for lease in leases]
 166         deleted_leases = list(set(current_leases).difference(kept_leases))
 167
 168         try:
 169             if peer:
 170                 self.driver.shell.UnBindObjectFromPeer('slice', slice['slice_id'], peer['shortname'])
 171             deleted=self.driver.shell.DeleteLeases(deleted_leases)
 172             for lease in requested_leases:
 173                 added=self.driver.shell.AddLeases(lease['hostname'], slice['name'], int(lease['start_time']), int(lease['duration']) * grain + int(lease['start_time']))
 174
 175         except:
 176             logger.log_exc('Failed to add/remove slice leases')
 177
 178         return leases
 179
 180
 181     def verify_slice_nodes(self, slice, requested_slivers, peer):
 182
 183         nodes = self.driver.shell.GetNodes(slice['node_ids'], ['node_id', 'hostname', 'interface_ids'])
 184         current_slivers = [node['hostname'] for node in nodes]
 185
 186         # remove nodes not in rspec
 187         deleted_nodes = list(set(current_slivers).difference(requested_slivers))
 188
 189         # add nodes from rspec
 190         added_nodes = list(set(requested_slivers).difference(current_slivers))
 191
 192         try:
 193             if peer:
 194                 self.driver.shell.UnBindObjectFromPeer('slice', slice['slice_id'], peer['shortname'])
 195             self.driver.shell.AddSliceToNodes(slice['name'], added_nodes)
 196             self.driver.shell.DeleteSliceFromNodes(slice['name'], deleted_nodes)
 197
 198         except:
 199             logger.log_exc('Failed to add/remove slice from nodes')
 200         return nodes
 201
 202     def free_egre_key(self):
 203         used = set()
 204         for tag in self.driver.shell.GetSliceTags({'tagname': 'egre_key'}):
 205                 used.add(int(tag['value']))
 206
 207         for i in range(1, 256):
 208             if i not in used:
 209                 key = i
 210                 break
 211         else:
 212             raise KeyError("No more EGRE keys available")
 213
 214         return str(key)
 215
 216     def verify_slice_links(self, slice, requested_links, nodes):
 217         # nodes is undefined here
 218         if not requested_links:
 219             return
 220
 221         # build dict of nodes
 222         nodes_dict = {}
 223         interface_ids = []
 224         for node in nodes:
 225             nodes_dict[node['node_id']] = node
 226             interface_ids.extend(node['interface_ids'])
 227         # build dict of interfaces
 228         interfaces = self.driver.shell.GetInterfaces(interface_ids)
 229         interfaces_dict = {}
 230         for interface in interfaces:
 231             interfaces_dict[interface['interface_id']] = interface
 232
 233         slice_tags = []
 234
 235         # set egre key
 236         slice_tags.append({'name': 'egre_key', 'value': self.free_egre_key()})
 237
 238         # set netns
 239         slice_tags.append({'name': 'netns', 'value': '1'})
 240
 241         # set cap_net_admin
 242         # need to update the attribute string?
 243         slice_tags.append({'name': 'capabilities', 'value': 'CAP_NET_ADMIN'})
 244
 245         for link in requested_links:
 246             # get the ip address of the first node in the link
 247             ifname1 = Xrn(link['interface1']['component_id']).get_leaf()
 248             (node_raw, device) = ifname1.split(':')
 249             node_id = int(node_raw.replace('node', ''))
 250             node = nodes_dict[node_id]
 251             if1 = interfaces_dict[node['interface_ids'][0]]
 252             ipaddr = if1['ip']
 253             topo_rspec = VLink.get_topo_rspec(link, ipaddr)
 254             # set topo_rspec tag
 255             slice_tags.append({'name': 'topo_rspec', 'value': str([topo_rspec]), 'node_id': node_id})
 256             # set vini_topo tag
 257             slice_tags.append({'name': 'vini_topo', 'value': 'manual', 'node_id': node_id})
 258             #self.driver.shell.AddSliceTag(slice['name'], 'topo_rspec', str([topo_rspec]), node_id)
 259
 260         self.verify_slice_attributes(slice, slice_tags, {'append': True}, admin=True)
 261
 262
 263
 264     def handle_peer(self, site, slice, persons, peer):
 265         if peer:
 266             # bind site
 267             try:
 268                 if site:
 269                     self.driver.shell.BindObjectToPeer('site', site['site_id'], peer['shortname'], slice['site_id'])
 270             except Exception,e:
 271                 self.driver.shell.DeleteSite(site['site_id'])
 272                 raise e
 273
 274             # bind slice
 275             try:
 276                 if slice:
 277                     self.driver.shell.BindObjectToPeer('slice', slice['slice_id'], peer['shortname'], slice['slice_id'])
 278             except Exception,e:
 279                 self.driver.shell.DeleteSlice(slice['slice_id'])
 280                 raise e
 281
 282             # bind persons
 283             for person in persons:
 284                 try:
 285                     self.driver.shell.BindObjectToPeer('person',
 286                                                      person['person_id'], peer['shortname'], person['peer_person_id'])
 287
 288                     for (key, remote_key_id) in zip(person['keys'], person['key_ids']):
 289                         try:
 290                             self.driver.shell.BindObjectToPeer( 'key', key['key_id'], peer['shortname'], remote_key_id)
 291                         except:
 292                             self.driver.shell.DeleteKey(key['key_id'])
 293                             logger("failed to bind key: %s to peer: %s " % (key['key_id'], peer['shortname']))
 294                 except Exception,e:
 295                     self.driver.shell.DeletePerson(person['person_id'])
 296                     raise e
 297
 298         return slice
 299
 300     def verify_site(self, slice_xrn, slice_record={}, peer=None, sfa_peer=None, options={}):
 301         (slice_hrn, type) = urn_to_hrn(slice_xrn)
 302         site_hrn = get_authority(slice_hrn)
 303         # login base can't be longer than 20 characters
 304         slicename = hrn_to_pl_slicename(slice_hrn)
 305         authority_name = slicename.split('_')[0]
 306         login_base = authority_name[:20]
 307         sites = self.driver.shell.GetSites(login_base)
 308         if not sites:
 309             # create new site record
 310             site = {'name': 'geni.%s' % authority_name,
 311                     'abbreviated_name': authority_name,
 312                     'login_base': login_base,
 313                     'max_slices': 100,
 314                     'max_slivers': 1000,
 315                     'enabled': True,
 316                     'peer_site_id': None}
 317             if peer:
 318                 site['peer_site_id'] = slice_record.get('site_id', None)
 319             site['site_id'] = self.driver.shell.AddSite(site)
 320             # exempt federated sites from monitor policies
 321             self.driver.shell.AddSiteTag(site['site_id'], 'exempt_site_until', "20200101")
 322
 323 #            # is this still necessary?
 324 #            # add record to the local registry
 325 #            if sfa_peer and slice_record:
 326 #                peer_dict = {'type': 'authority', 'hrn': site_hrn, \
 327 #                             'peer_authority': sfa_peer, 'pointer': site['site_id']}
 328 #                self.registry.register_peer_object(self.credential, peer_dict)
 329         else:
 330             site =  sites[0]
 331             if peer:
 332                 # unbind from peer so we can modify if necessary. Will bind back later
 333                 self.driver.shell.UnBindObjectFromPeer('site', site['site_id'], peer['shortname'])
 334
 335         return site
 336
 337     def verify_slice(self, slice_hrn, slice_record, peer, sfa_peer, options={}):
 338         slicename = hrn_to_pl_slicename(slice_hrn)
 339         parts = slicename.split("_")
 340         login_base = parts[0]
 341         slices = self.driver.shell.GetSlices([slicename])
 342         if not slices:
 343             slice = {'name': slicename,
 344                      'url': slice_record.get('url', slice_hrn),
 345                      'description': slice_record.get('description', slice_hrn)}
 346             # add the slice
 347             slice['slice_id'] = self.driver.shell.AddSlice(slice)
 348             slice['node_ids'] = []
 349             slice['person_ids'] = []
 350             if peer:
 351                 slice['peer_slice_id'] = slice_record.get('slice_id', None)
 352             # mark this slice as an sfa peer record
 353 #            if sfa_peer:
 354 #                peer_dict = {'type': 'slice', 'hrn': slice_hrn,
 355 #                             'peer_authority': sfa_peer, 'pointer': slice['slice_id']}
 356 #                self.registry.register_peer_object(self.credential, peer_dict)
 357         else:
 358             slice = slices[0]
 359             if peer:
 360                 slice['peer_slice_id'] = slice_record.get('slice_id', None)
 361                 # unbind from peer so we can modify if necessary. Will bind back later
 362                 self.driver.shell.UnBindObjectFromPeer('slice', slice['slice_id'], peer['shortname'])
 363                 #Update existing record (e.g. expires field) it with the latest info.
 364             if slice_record.get('expires'):
 365                 requested_expires = int(datetime_to_epoch(utcparse(slice_record['expires'])))
 366                 if requested_expires and slice['expires'] != requested_expires:
 367                     self.driver.shell.UpdateSlice( slice['slice_id'], {'expires' : requested_expires})
 368
 369         return slice
 370
 371     #def get_existing_persons(self, users):
 372     def verify_persons(self, slice_hrn, slice_record, users, peer, sfa_peer, options={}):
 373         users_by_email = {}
 374         users_by_site = defaultdict(list)
 375         users_dict = {}
 376         for user in users:
 377             user['urn'] = user['urn'].lower()
 378             hrn, type = urn_to_hrn(user['urn'])
 379             username = get_leaf(hrn)
 380             login_base = PlXrn(xrn=user['urn']).pl_login_base()
 381             user['username'] = username
 382             user['site'] = login_base
 383
 384             if 'email' in user:
 385                 user['email'] = user['email'].lower()
 386                 users_by_email[user['email']] = user
 387                 users_dict[user['email']] = user
 388             else:
 389                 users_by_site[user['site']].append(user)
 390
 391         # start building a list of existing users
 392         existing_user_ids = []
 393         existing_user_ids_filter = []
 394         if users_by_email:
 395             existing_user_ids_filter.extend(users_by_email.keys())
 396         if users_by_site:
 397             for login_base in users_by_site:
 398                 users = users_by_site[login_base]
 399                 for user in users:
 400                     existing_user_ids_filter.append(user['username']+'@geni.net')
 401         if existing_user_ids_filter:
 402             # get existing users by email
 403             existing_users = self.driver.shell.GetPersons({'email': existing_user_ids_filter},
 404                                                         ['person_id', 'key_ids', 'email'])
 405             existing_user_ids.extend([user['email'] for user in existing_users])
 406
 407         if users_by_site:
 408             # get a list of user sites (based on requeste user urns
 409             site_list = self.driver.shell.GetSites(users_by_site.keys(), \
 410                 ['site_id', 'login_base', 'person_ids'])
 411             # get all existing users at these sites
 412             sites = {}
 413             site_user_ids = []
 414             for site in site_list:
 415                 sites[site['site_id']] = site
 416                 site_user_ids.extend(site['person_ids'])
 417
 418             existing_site_persons_list = self.driver.shell.GetPersons(site_user_ids,
 419                                                                     ['person_id', 'key_ids', 'email', 'site_ids'])
 420
 421             # all requested users are either existing users or new (added) users
 422             for login_base in users_by_site:
 423                 requested_site_users = users_by_site[login_base]
 424                 for requested_user in requested_site_users:
 425                     user_found = False
 426                     for existing_user in existing_site_persons_list:
 427                         for site_id in existing_user['site_ids']:
 428                             if site_id in sites:
 429                                 site = sites[site_id]
 430                                 if login_base == site['login_base'] and \
 431                                    existing_user['email'].startswith(requested_user['username']+'@'):
 432                                     existing_user_ids.append(existing_user['email'])
 433                                     requested_user['email'] = existing_user['email']
 434                                     users_dict[existing_user['email']] = requested_user
 435                                     user_found = True
 436                                     break
 437                         if user_found:
 438                             break
 439
 440                     if user_found == False:
 441                         fake_email = requested_user['username'] + '@geni.net'
 442                         requested_user['email'] = fake_email
 443                         users_dict[fake_email] = requested_user
 444
 445         # requested slice users
 446         requested_user_ids = users_dict.keys()
 447         # existing slice users
 448         existing_slice_users_filter = {'person_id': slice_record.get('person_ids', [])}
 449         existing_slice_users = self.driver.shell.GetPersons(existing_slice_users_filter,
 450                                                           ['person_id', 'key_ids', 'email'])
 451         existing_slice_user_ids = [user['email'] for user in existing_slice_users]
 452
 453         # users to be added, removed or updated
 454         added_user_ids = set(requested_user_ids).difference(existing_user_ids)
 455         added_slice_user_ids = set(requested_user_ids).difference(existing_slice_user_ids)
 456         removed_user_ids = set(existing_slice_user_ids).difference(requested_user_ids)
 457         updated_user_ids = set(existing_slice_user_ids).intersection(requested_user_ids)
 458
 459         # Remove stale users (only if we are not appending).
 460         # Append by default.
 461         append = options.get('append', True)
 462         if append == False:
 463             for removed_user_id in removed_user_ids:
 464                 self.driver.shell.DeletePersonFromSlice(removed_user_id, slice_record['name'])
 465         # update_existing users
 466         updated_users_list = [user for user in users_dict.values() if user['email'] in \
 467           updated_user_ids]
 468         self.verify_keys(existing_slice_users, updated_users_list, peer, options)
 469
 470         added_persons = []
 471         # add new users
 472         for added_user_id in added_user_ids:
 473             added_user = users_dict[added_user_id]
 474             hrn, type = urn_to_hrn(added_user['urn'])
 475             person = {
 476                 'first_name': added_user.get('first_name', hrn),
 477                 'last_name': added_user.get('last_name', hrn),
 478                 'email': added_user_id,
 479                 'peer_person_id': None,
 480                 'keys': [],
 481                 'key_ids': added_user.get('key_ids', []),
 482             }
 483             person['person_id'] = self.driver.shell.AddPerson(person)
 484             if peer:
 485                 person['peer_person_id'] = added_user['person_id']
 486             added_persons.append(person)
 487
 488             # enable the account
 489             self.driver.shell.UpdatePerson(person['person_id'], {'enabled': True})
 490
 491             # add person to site
 492             self.driver.shell.AddPersonToSite(added_user_id, added_user['site'])
 493
 494             for key_string in added_user.get('keys', []):
 495                 key = {'key':key_string, 'key_type':'ssh'}
 496                 key['key_id'] = self.driver.shell.AddPersonKey(person['person_id'], key)
 497                 person['keys'].append(key)
 498
 499             # add the registry record
 500 #            if sfa_peer:
 501 #                peer_dict = {'type': 'user', 'hrn': hrn, 'peer_authority': sfa_peer, \
 502 #                    'pointer': person['person_id']}
 503 #                self.registry.register_peer_object(self.credential, peer_dict)
 504
 505         for added_slice_user_id in added_slice_user_ids.union(added_user_ids):
 506             # add person to the slice
 507             self.driver.shell.AddPersonToSlice(added_slice_user_id, slice_record['name'])
 508             # if this is a peer record then it should already be bound to a peer.
 509             # no need to return worry about it getting bound later
 510
 511         return added_persons
 512
 513
 514     def verify_keys(self, persons, users, peer, options={}):
 515         # existing keys
 516         key_ids = []
 517         for person in persons:
 518             key_ids.extend(person['key_ids'])
 519         keylist = self.driver.shell.GetKeys(key_ids, ['key_id', 'key'])
 520         keydict = {}
 521         for key in keylist:
 522             keydict[key['key']] = key['key_id']
 523         existing_keys = keydict.keys()
 524         persondict = {}
 525         for person in persons:
 526             persondict[person['email']] = person
 527
 528         # add new keys
 529         requested_keys = []
 530         updated_persons = []
 531         for user in users:
 532             user_keys = user.get('keys', [])
 533             updated_persons.append(user)
 534             for key_string in user_keys:
 535                 requested_keys.append(key_string)
 536                 if key_string not in existing_keys:
 537                     key = {'key': key_string, 'key_type': 'ssh'}
 538                     try:
 539                         if peer:
 540                             person = persondict[user['email']]
 541                             self.driver.shell.UnBindObjectFromPeer('person', person['person_id'], peer['shortname'])
 542                         key['key_id'] = self.driver.shell.AddPersonKey(user['email'], key)
 543                         if peer:
 544                             key_index = user_keys.index(key['key'])
 545                             remote_key_id = user['key_ids'][key_index]
 546                             self.driver.shell.BindObjectToPeer('key', key['key_id'], peer['shortname'], remote_key_id)
 547
 548                     finally:
 549                         if peer:
 550                             self.driver.shell.BindObjectToPeer('person', person['person_id'], peer['shortname'], user['person_id'])
 551
 552         # remove old keys (only if we are not appending)
 553         append = options.get('append', True)
 554         if append == False:
 555             removed_keys = set(existing_keys).difference(requested_keys)
 556             for existing_key_id in keydict:
 557                 if keydict[existing_key_id] in removed_keys:
 558                     try:
 559                         if peer:
 560                             self.driver.shell.UnBindObjectFromPeer('key', existing_key_id, peer['shortname'])
 561                         self.driver.shell.DeleteKey(existing_key_id)
 562                     except:
 563                         pass
 564
 565     def verify_slice_attributes(self, slice, requested_slice_attributes, options={}, admin=False):
 566         append = options.get('append', True)
 567         # get list of attributes users ar able to manage
 568         filter = {'category': '*slice*'}
 569         if not admin:
 570             filter['|roles'] = ['user']
 571         slice_attributes = self.driver.shell.GetTagTypes(filter)
 572         valid_slice_attribute_names = [attribute['tagname'] for attribute in slice_attributes]
 573
 574         # get sliver attributes
 575         added_slice_attributes = []
 576         removed_slice_attributes = []
 577         ignored_slice_attribute_names = []
 578         existing_slice_attributes = self.driver.shell.GetSliceTags({'slice_id': slice['slice_id']})
 579
 580         # get attributes that should be removed
 581         for slice_tag in existing_slice_attributes:
 582             if slice_tag['tagname'] in ignored_slice_attribute_names:
 583                 # If a slice already has a admin only role it was probably given to them by an
 584                 # admin, so we should ignore it.
 585                 ignored_slice_attribute_names.append(slice_tag['tagname'])
 586             else:
 587                 # If an existing slice attribute was not found in the request it should
 588                 # be removed
 589                 attribute_found=False
 590                 for requested_attribute in requested_slice_attributes:
 591                     if requested_attribute['name'] == slice_tag['tagname'] and \
 592                        requested_attribute['value'] == slice_tag['value']:
 593                         attribute_found=True
 594                         break
 595
 596             if not attribute_found and not append:
 597                 removed_slice_attributes.append(slice_tag)
 598
 599         # get attributes that should be added:
 600         for requested_attribute in requested_slice_attributes:
 601             # if the requested attribute wasn't found  we should add it
 602             if requested_attribute['name'] in valid_slice_attribute_names:
 603                 attribute_found = False
 604                 for existing_attribute in existing_slice_attributes:
 605                     if requested_attribute['name'] == existing_attribute['tagname'] and \
 606                        requested_attribute['value'] == existing_attribute['value']:
 607                         attribute_found=True
 608                         break
 609                 if not attribute_found:
 610                     added_slice_attributes.append(requested_attribute)
 611
 612
 613         # remove stale attributes
 614         for attribute in removed_slice_attributes:
 615             try:
 616                 self.driver.shell.DeleteSliceTag(attribute['slice_tag_id'])
 617             except Exception, e:
 618                 logger.warn('Failed to remove sliver attribute. name: %s, value: %s, node_id: %s\nCause:%s'\
 619                                 % (slice['name'], attribute['value'],  attribute.get('node_id'), str(e)))
 620
 621         # add requested_attributes
 622         for attribute in added_slice_attributes:
 623             try:
 624                 self.driver.shell.AddSliceTag(slice['name'], attribute['name'], attribute['value'], attribute.get('node_id', None))
 625             except Exception, e:
 626                 logger.warn('Failed to add sliver attribute. name: %s, value: %s, node_id: %s\nCause:%s'\
 627                                 % (slice['name'], attribute['value'],  attribute.get('node_id'), str(e)))
 628