sfa/planetlab/plslices.py

   1 from types import StringTypes
   2 from collections import defaultdict
   3
   4 from sfa.util.sfatime import utcparse, datetime_to_epoch
   5 from sfa.util.sfalogging import logger
   6 from sfa.util.xrn import Xrn, get_leaf, get_authority, urn_to_hrn
   7
   8 from sfa.rspecs.rspec import RSpec
   9
  10 from sfa.planetlab.vlink import VLink
  11 from sfa.planetlab.plxrn import PlXrn, hrn_to_pl_slicename
  12
  13 MAXINT =  2L**31-1
  14
  15 class PlSlices:
  16
  17     rspec_to_slice_tag = {'max_rate':'net_max_rate'}
  18
  19     def __init__(self, driver):
  20         self.driver = driver
  21
  22     def get_slivers(self, xrn, node=None):
  23         hrn, type = urn_to_hrn(xrn)
  24
  25         slice_name = hrn_to_pl_slicename(hrn)
  26         # XX Should we just call PLCAPI.GetSliceTicket(slice_name) instead
  27         # of doing all of this?
  28         #return self.driver.shell.GetSliceTicket(self.auth, slice_name)
  29
  30         # from PLCAPI.GetSlivers.get_slivers()
  31         slice_fields = ['slice_id', 'name', 'instantiation', 'expires', 'person_ids', 'slice_tag_ids']
  32         slices = self.driver.shell.GetSlices(slice_name, slice_fields)
  33         # Build up list of users and slice attributes
  34         person_ids = set()
  35         all_slice_tag_ids = set()
  36         for slice in slices:
  37             person_ids.update(slice['person_ids'])
  38             all_slice_tag_ids.update(slice['slice_tag_ids'])
  39         person_ids = list(person_ids)
  40         all_slice_tag_ids = list(all_slice_tag_ids)
  41         # Get user information
  42         all_persons_list = self.driver.shell.GetPersons({'person_id':person_ids,'enabled':True}, ['person_id', 'enabled', 'key_ids'])
  43         all_persons = {}
  44         for person in all_persons_list:
  45             all_persons[person['person_id']] = person
  46
  47         # Build up list of keys
  48         key_ids = set()
  49         for person in all_persons.values():
  50             key_ids.update(person['key_ids'])
  51         key_ids = list(key_ids)
  52         # Get user account keys
  53         all_keys_list = self.driver.shell.GetKeys(key_ids, ['key_id', 'key', 'key_type'])
  54         all_keys = {}
  55         for key in all_keys_list:
  56             all_keys[key['key_id']] = key
  57         # Get slice attributes
  58         all_slice_tags_list = self.driver.shell.GetSliceTags(all_slice_tag_ids)
  59         all_slice_tags = {}
  60         for slice_tag in all_slice_tags_list:
  61             all_slice_tags[slice_tag['slice_tag_id']] = slice_tag
  62
  63         slivers = []
  64         for slice in slices:
  65             keys = []
  66             for person_id in slice['person_ids']:
  67                 if person_id in all_persons:
  68                     person = all_persons[person_id]
  69                     if not person['enabled']:
  70                         continue
  71                     for key_id in person['key_ids']:
  72                         if key_id in all_keys:
  73                             key = all_keys[key_id]
  74                             keys += [{'key_type': key['key_type'],
  75                                     'key': key['key']}]
  76             attributes = []
  77             # All (per-node and global) attributes for this slice
  78             slice_tags = []
  79             for slice_tag_id in slice['slice_tag_ids']:
  80                 if slice_tag_id in all_slice_tags:
  81                     slice_tags.append(all_slice_tags[slice_tag_id])
  82             # Per-node sliver attributes take precedence over global
  83             # slice attributes, so set them first.
  84             # Then comes nodegroup slice attributes
  85             # Followed by global slice attributes
  86             sliver_attributes = []
  87
  88             if node is not None:
  89                 for sliver_attribute in filter(lambda a: a['node_id'] == node['node_id'], slice_tags):
  90                     sliver_attributes.append(sliver_attribute['tagname'])
  91                     attributes.append({'tagname': sliver_attribute['tagname'],
  92                                     'value': sliver_attribute['value']})
  93
  94             # set nodegroup slice attributes
  95             for slice_tag in filter(lambda a: a['nodegroup_id'] in node['nodegroup_ids'], slice_tags):
  96                 # Do not set any nodegroup slice attributes for
  97                 # which there is at least one sliver attribute
  98                 # already set.
  99                 if slice_tag not in slice_tags:
 100                     attributes.append({'tagname': slice_tag['tagname'],
 101                         'value': slice_tag['value']})
 102
 103             for slice_tag in filter(lambda a: a['node_id'] is None, slice_tags):
 104                 # Do not set any global slice attributes for
 105                 # which there is at least one sliver attribute
 106                 # already set.
 107                 if slice_tag['tagname'] not in sliver_attributes:
 108                     attributes.append({'tagname': slice_tag['tagname'],
 109                                    'value': slice_tag['value']})
 110
 111             # XXX Sanity check; though technically this should be a system invariant
 112             # checked with an assertion
 113             if slice['expires'] > MAXINT:  slice['expires']= MAXINT
 114
 115             slivers.append({
 116                 'hrn': hrn,
 117                 'name': slice['name'],
 118                 'slice_id': slice['slice_id'],
 119                 'instantiation': slice['instantiation'],
 120                 'expires': slice['expires'],
 121                 'keys': keys,
 122                 'attributes': attributes
 123             })
 124
 125         return slivers
 126
 127     def get_peer(self, xrn):
 128         hrn, type = urn_to_hrn(xrn)
 129         # Becaues of myplc federation,  we first need to determine if this
 130         # slice belongs to out local plc or a myplc peer. We will assume it
 131         # is a local site, unless we find out otherwise
 132         peer = None
 133
 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
 140         # check if we are already peered with this site_authority, if so
 141         peers = self.driver.shell.GetPeers({}, ['peer_id', 'peername', 'shortname', 'hrn_root'])
 142         for peer_record in peers:
 143             names = [name.lower() for name in peer_record.values() if isinstance(name, StringTypes)]
 144             if site_authority in names:
 145                 peer = peer_record
 146
 147         return peer
 148
 149     def get_sfa_peer(self, xrn):
 150         hrn, type = urn_to_hrn(xrn)
 151
 152         # return the authority for this hrn or None if we are the authority
 153         sfa_peer = None
 154         slice_authority = get_authority(hrn)
 155         site_authority = get_authority(slice_authority)
 156
 157         if site_authority != self.driver.hrn:
 158             sfa_peer = site_authority
 159
 160         return sfa_peer
 161
 162     def verify_slice_leases(self, slice, requested_leases, kept_leases, peer):
 163
 164         leases = self.driver.shell.GetLeases({'name':slice['name']}, ['lease_id'])
 165         grain = self.driver.shell.GetLeaseGranularity()
 166         current_leases = [lease['lease_id'] for lease in leases]
 167         deleted_leases = list(set(current_leases).difference(kept_leases))
 168
 169         try:
 170             if peer:
 171                 self.driver.shell.UnBindObjectFromPeer('slice', slice['slice_id'], peer['shortname'])
 172             deleted=self.driver.shell.DeleteLeases(deleted_leases)
 173             for lease in requested_leases:
 174                 added=self.driver.shell.AddLeases(lease['hostname'], slice['name'], int(lease['start_time']), int(lease['duration']) * grain + int(lease['start_time']))
 175
 176         except:
 177             logger.log_exc('Failed to add/remove slice leases')
 178
 179         return leases
 180
 181
 182     def verify_slice_nodes(self, slice, requested_slivers, peer):
 183
 184         nodes = self.driver.shell.GetNodes(slice['node_ids'], ['node_id', 'hostname', 'interface_ids'])
 185         current_slivers = [node['hostname'] for node in nodes]
 186
 187         # remove nodes not in rspec
 188         deleted_nodes = list(set(current_slivers).difference(requested_slivers))
 189
 190         # add nodes from rspec
 191         added_nodes = list(set(requested_slivers).difference(current_slivers))
 192
 193         try:
 194             if peer:
 195                 self.driver.shell.UnBindObjectFromPeer('slice', slice['slice_id'], peer['shortname'])
 196             self.driver.shell.AddSliceToNodes(slice['name'], added_nodes)
 197             self.driver.shell.DeleteSliceFromNodes(slice['name'], deleted_nodes)
 198
 199         except:
 200             logger.log_exc('Failed to add/remove slice from nodes')
 201         return nodes
 202
 203     def free_egre_key(self):
 204         used = set()
 205         for tag in self.driver.shell.GetSliceTags({'tagname': 'egre_key'}):
 206                 used.add(int(tag['value']))
 207
 208         for i in range(1, 256):
 209             if i not in used:
 210                 key = i
 211                 break
 212         else:
 213             raise KeyError("No more EGRE keys available")
 214
 215         return str(key)
 216
 217     def verify_slice_links(self, slice, requested_links, nodes):
 218         # nodes is undefined here
 219         if not requested_links:
 220             return
 221
 222         # build dict of nodes
 223         nodes_dict = {}
 224         interface_ids = []
 225         for node in nodes:
 226             nodes_dict[node['node_id']] = node
 227             interface_ids.extend(node['interface_ids'])
 228         # build dict of interfaces
 229         interfaces = self.driver.shell.GetInterfaces(interface_ids)
 230         interfaces_dict = {}
 231         for interface in interfaces:
 232             interfaces_dict[interface['interface_id']] = interface
 233
 234         slice_tags = []
 235
 236         # set egre key
 237         slice_tags.append({'name': 'egre_key', 'value': self.free_egre_key()})
 238
 239         # set netns
 240         slice_tags.append({'name': 'netns', 'value': '1'})
 241
 242         # set cap_net_admin
 243         # need to update the attribute string?
 244         slice_tags.append({'name': 'capabilities', 'value': 'CAP_NET_ADMIN'})
 245
 246         for link in requested_links:
 247             # get the ip address of the first node in the link
 248             ifname1 = Xrn(link['interface1']['component_id']).get_leaf()
 249             (node_raw, device) = ifname1.split(':')
 250             node_id = int(node_raw.replace('node', ''))
 251             node = nodes_dict[node_id]
 252             if1 = interfaces_dict[node['interface_ids'][0]]
 253             ipaddr = if1['ip']
 254             topo_rspec = VLink.get_topo_rspec(link, ipaddr)
 255             # set topo_rspec tag
 256             slice_tags.append({'name': 'topo_rspec', 'value': str([topo_rspec]), 'node_id': node_id})
 257             # set vini_topo tag
 258             slice_tags.append({'name': 'vini_topo', 'value': 'manual', 'node_id': node_id})
 259             #self.driver.shell.AddSliceTag(slice['name'], 'topo_rspec', str([topo_rspec]), node_id)
 260
 261         self.verify_slice_attributes(slice, slice_tags, {'append': True}, admin=True)
 262
 263
 264
 265     def handle_peer(self, site, slice, persons, peer):
 266         if peer:
 267             # bind site
 268             try:
 269                 if site:
 270                     self.driver.shell.BindObjectToPeer('site', site['site_id'], peer['shortname'], slice['site_id'])
 271             except Exception,e:
 272                 self.driver.shell.DeleteSite(site['site_id'])
 273                 raise e
 274
 275             # bind slice
 276             try:
 277                 if slice:
 278                     self.driver.shell.BindObjectToPeer('slice', slice['slice_id'], peer['shortname'], slice['slice_id'])
 279             except Exception,e:
 280                 self.driver.shell.DeleteSlice(slice['slice_id'])
 281                 raise e
 282
 283             # bind persons
 284             for person in persons:
 285                 try:
 286                     self.driver.shell.BindObjectToPeer('person',
 287                                                      person['person_id'], peer['shortname'], person['peer_person_id'])
 288
 289                     for (key, remote_key_id) in zip(person['keys'], person['key_ids']):
 290                         try:
 291                             self.driver.shell.BindObjectToPeer( 'key', key['key_id'], peer['shortname'], remote_key_id)
 292                         except:
 293                             self.driver.shell.DeleteKey(key['key_id'])
 294                             logger("failed to bind key: %s to peer: %s " % (key['key_id'], peer['shortname']))
 295                 except Exception,e:
 296                     self.driver.shell.DeletePerson(person['person_id'])
 297                     raise e
 298
 299         return slice
 300
 301     def verify_site(self, slice_xrn, slice_record={}, peer=None, sfa_peer=None, options={}):
 302         (slice_hrn, type) = urn_to_hrn(slice_xrn)
 303         site_hrn = get_authority(slice_hrn)
 304         # login base can't be longer than 20 characters
 305         slicename = hrn_to_pl_slicename(slice_hrn)
 306         authority_name = slicename.split('_')[0]
 307         login_base = authority_name[:20]
 308         sites = self.driver.shell.GetSites(login_base)
 309         if not sites:
 310             # create new site record
 311             site = {'name': 'geni.%s' % authority_name,
 312                     'abbreviated_name': authority_name,
 313                     'login_base': login_base,
 314                     'max_slices': 100,
 315                     'max_slivers': 1000,
 316                     'enabled': True,
 317                     'peer_site_id': None}
 318             if peer:
 319                 site['peer_site_id'] = slice_record.get('site_id', None)
 320             site['site_id'] = self.driver.shell.AddSite(site)
 321             # exempt federated sites from monitor policies
 322             self.driver.shell.AddSiteTag(site['site_id'], 'exempt_site_until', "20200101")
 323
 324 #            # is this still necessary?
 325 #            # add record to the local registry
 326 #            if sfa_peer and slice_record:
 327 #                peer_dict = {'type': 'authority', 'hrn': site_hrn, \
 328 #                             'peer_authority': sfa_peer, 'pointer': site['site_id']}
 329 #                self.registry.register_peer_object(self.credential, peer_dict)
 330         else:
 331             site =  sites[0]
 332             if peer:
 333                 # unbind from peer so we can modify if necessary. Will bind back later
 334                 self.driver.shell.UnBindObjectFromPeer('site', site['site_id'], peer['shortname'])
 335
 336         return site
 337
 338     def verify_slice(self, slice_hrn, slice_record, peer, sfa_peer, options={}):
 339         slicename = hrn_to_pl_slicename(slice_hrn)
 340         parts = slicename.split("_")
 341         login_base = parts[0]
 342         slices = self.driver.shell.GetSlices([slicename])
 343         if not slices:
 344             slice = {'name': slicename,
 345                      'url': slice_record.get('url', slice_hrn),
 346                      'description': slice_record.get('description', slice_hrn)}
 347             # add the slice
 348             slice['slice_id'] = self.driver.shell.AddSlice(slice)
 349             slice['node_ids'] = []
 350             slice['person_ids'] = []
 351             if peer:
 352                 slice['peer_slice_id'] = slice_record.get('slice_id', None)
 353             # mark this slice as an sfa peer record
 354 #            if sfa_peer:
 355 #                peer_dict = {'type': 'slice', 'hrn': slice_hrn,
 356 #                             'peer_authority': sfa_peer, 'pointer': slice['slice_id']}
 357 #                self.registry.register_peer_object(self.credential, peer_dict)
 358         else:
 359             slice = slices[0]
 360             if peer:
 361                 slice['peer_slice_id'] = slice_record.get('slice_id', None)
 362                 # unbind from peer so we can modify if necessary. Will bind back later
 363                 self.driver.shell.UnBindObjectFromPeer('slice', slice['slice_id'], peer['shortname'])
 364                 #Update existing record (e.g. expires field) it with the latest info.
 365             if slice_record.get('expires'):
 366                 requested_expires = int(datetime_to_epoch(utcparse(slice_record['expires'])))
 367                 if requested_expires and slice['expires'] != requested_expires:
 368                     self.driver.shell.UpdateSlice( slice['slice_id'], {'expires' : requested_expires})
 369
 370         return slice
 371
 372     #def get_existing_persons(self, users):
 373     def verify_persons(self, slice_hrn, slice_record, users, peer, sfa_peer, options={}):
 374         users_by_email = {}
 375         users_by_site = defaultdict(list)
 376         users_dict = {}
 377         for user in users:
 378             user['urn'] = user['urn'].lower()
 379             hrn, type = urn_to_hrn(user['urn'])
 380             username = get_leaf(hrn)
 381             login_base = PlXrn(xrn=user['urn']).pl_login_base()
 382             user['username'] = username
 383             user['site'] = login_base
 384
 385             if 'email' in user:
 386                 user['email'] = user['email'].lower()
 387                 users_by_email[user['email']] = user
 388                 users_dict[user['email']] = user
 389             else:
 390                 users_by_site[user['site']].append(user)
 391
 392         # start building a list of existing users
 393         existing_user_ids = []
 394         existing_user_ids_filter = []
 395         if users_by_email:
 396             existing_user_ids_filter.extend(users_by_email.keys())
 397         if users_by_site:
 398             for login_base in users_by_site:
 399                 users = users_by_site[login_base]
 400                 for user in users:
 401                     existing_user_ids_filter.append(user['username']+'@geni.net')
 402         if existing_user_ids_filter:
 403             # get existing users by email
 404             existing_users = self.driver.shell.GetPersons({'email': existing_user_ids_filter},
 405                                                         ['person_id', 'key_ids', 'email'])
 406             existing_user_ids.extend([user['email'] for user in existing_users])
 407
 408         if users_by_site:
 409             # get a list of user sites (based on requeste user urns
 410             site_list = self.driver.shell.GetSites(users_by_site.keys(), \
 411                 ['site_id', 'login_base', 'person_ids'])
 412             # get all existing users at these sites
 413             sites = {}
 414             site_user_ids = []
 415             for site in site_list:
 416                 sites[site['site_id']] = site
 417                 site_user_ids.extend(site['person_ids'])
 418
 419             existing_site_persons_list = self.driver.shell.GetPersons(site_user_ids,
 420                                                                     ['person_id', 'key_ids', 'email', 'site_ids'])
 421
 422             # all requested users are either existing users or new (added) users
 423             for login_base in users_by_site:
 424                 requested_site_users = users_by_site[login_base]
 425                 for requested_user in requested_site_users:
 426                     user_found = False
 427                     for existing_user in existing_site_persons_list:
 428                         for site_id in existing_user['site_ids']:
 429                             if site_id in sites:
 430                                 site = sites[site_id]
 431                                 if login_base == site['login_base'] and \
 432                                    existing_user['email'].startswith(requested_user['username']+'@'):
 433                                     existing_user_ids.append(existing_user['email'])
 434                                     requested_user['email'] = existing_user['email']
 435                                     users_dict[existing_user['email']] = requested_user
 436                                     user_found = True
 437                                     break
 438                         if user_found:
 439                             break
 440
 441                     if user_found == False:
 442                         fake_email = requested_user['username'] + '@geni.net'
 443                         requested_user['email'] = fake_email
 444                         users_dict[fake_email] = requested_user
 445
 446         # requested slice users
 447         requested_user_ids = users_dict.keys()
 448         # existing slice users
 449         existing_slice_users_filter = {'person_id': slice_record.get('person_ids', [])}
 450         existing_slice_users = self.driver.shell.GetPersons(existing_slice_users_filter,
 451                                                           ['person_id', 'key_ids', 'email'])
 452         existing_slice_user_ids = [user['email'] for user in existing_slice_users]
 453
 454         # users to be added, removed or updated
 455         added_user_ids = set(requested_user_ids).difference(existing_user_ids)
 456         added_slice_user_ids = set(requested_user_ids).difference(existing_slice_user_ids)
 457         removed_user_ids = set(existing_slice_user_ids).difference(requested_user_ids)
 458         updated_user_ids = set(existing_slice_user_ids).intersection(requested_user_ids)
 459
 460         # Remove stale users (only if we are not appending).
 461         # Append by default.
 462         append = options.get('append', True)
 463         if append == False:
 464             for removed_user_id in removed_user_ids:
 465                 self.driver.shell.DeletePersonFromSlice(removed_user_id, slice_record['name'])
 466         # update_existing users
 467         updated_users_list = [user for user in users_dict.values() if user['email'] in \
 468           updated_user_ids]
 469         self.verify_keys(existing_slice_users, updated_users_list, peer, options)
 470
 471         added_persons = []
 472         # add new users
 473         for added_user_id in added_user_ids:
 474             added_user = users_dict[added_user_id]
 475             hrn, type = urn_to_hrn(added_user['urn'])
 476             person = {
 477                 'first_name': added_user.get('first_name', hrn),
 478                 'last_name': added_user.get('last_name', hrn),
 479                 'email': added_user_id,
 480                 'peer_person_id': None,
 481                 'keys': [],
 482                 'key_ids': added_user.get('key_ids', []),
 483             }
 484             person['person_id'] = self.driver.shell.AddPerson(person)
 485             if peer:
 486                 person['peer_person_id'] = added_user['person_id']
 487             added_persons.append(person)
 488
 489             # enable the account
 490             self.driver.shell.UpdatePerson(person['person_id'], {'enabled': True})
 491
 492             # add person to site
 493             self.driver.shell.AddPersonToSite(added_user_id, added_user['site'])
 494
 495             for key_string in added_user.get('keys', []):
 496                 key = {'key':key_string, 'key_type':'ssh'}
 497                 key['key_id'] = self.driver.shell.AddPersonKey(person['person_id'], key)
 498                 person['keys'].append(key)
 499
 500             # add the registry record
 501 #            if sfa_peer:
 502 #                peer_dict = {'type': 'user', 'hrn': hrn, 'peer_authority': sfa_peer, \
 503 #                    'pointer': person['person_id']}
 504 #                self.registry.register_peer_object(self.credential, peer_dict)
 505
 506         for added_slice_user_id in added_slice_user_ids.union(added_user_ids):
 507             # add person to the slice
 508             self.driver.shell.AddPersonToSlice(added_slice_user_id, slice_record['name'])
 509             # if this is a peer record then it should already be bound to a peer.
 510             # no need to return worry about it getting bound later
 511
 512         return added_persons
 513
 514
 515     def verify_keys(self, persons, users, peer, options={}):
 516         # existing keys
 517         key_ids = []
 518         for person in persons:
 519             key_ids.extend(person['key_ids'])
 520         keylist = self.driver.shell.GetKeys(key_ids, ['key_id', 'key'])
 521         keydict = {}
 522         for key in keylist:
 523             keydict[key['key']] = key['key_id']
 524         existing_keys = keydict.keys()
 525         persondict = {}
 526         for person in persons:
 527             persondict[person['email']] = person
 528
 529         # add new keys
 530         requested_keys = []
 531         updated_persons = []
 532         for user in users:
 533             user_keys = user.get('keys', [])
 534             updated_persons.append(user)
 535             for key_string in user_keys:
 536                 requested_keys.append(key_string)
 537                 if key_string not in existing_keys:
 538                     key = {'key': key_string, 'key_type': 'ssh'}
 539                     try:
 540                         if peer:
 541                             person = persondict[user['email']]
 542                             self.driver.shell.UnBindObjectFromPeer('person', person['person_id'], peer['shortname'])
 543                         key['key_id'] = self.driver.shell.AddPersonKey(user['email'], key)
 544                         if peer:
 545                             key_index = user_keys.index(key['key'])
 546                             remote_key_id = user['key_ids'][key_index]
 547                             self.driver.shell.BindObjectToPeer('key', key['key_id'], peer['shortname'], remote_key_id)
 548
 549                     finally:
 550                         if peer:
 551                             self.driver.shell.BindObjectToPeer('person', person['person_id'], peer['shortname'], user['person_id'])
 552
 553         # remove old keys (only if we are not appending)
 554         append = options.get('append', True)
 555         if append == False:
 556             removed_keys = set(existing_keys).difference(requested_keys)
 557             for existing_key_id in keydict:
 558                 if keydict[existing_key_id] in removed_keys:
 559                     try:
 560                         if peer:
 561                             self.driver.shell.UnBindObjectFromPeer('key', existing_key_id, peer['shortname'])
 562                         self.driver.shell.DeleteKey(existing_key_id)
 563                     except:
 564                         pass
 565
 566     def verify_slice_attributes(self, slice, requested_slice_attributes, options={}, admin=False):
 567         append = options.get('append', True)
 568         # get list of attributes users ar able to manage
 569         filter = {'category': '*slice*'}
 570         if not admin:
 571             filter['|roles'] = ['user']
 572         slice_attributes = self.driver.shell.GetTagTypes(filter)
 573         valid_slice_attribute_names = [attribute['tagname'] for attribute in slice_attributes]
 574
 575         # get sliver attributes
 576         added_slice_attributes = []
 577         removed_slice_attributes = []
 578         ignored_slice_attribute_names = []
 579         existing_slice_attributes = self.driver.shell.GetSliceTags({'slice_id': slice['slice_id']})
 580
 581         # get attributes that should be removed
 582         for slice_tag in existing_slice_attributes:
 583             if slice_tag['tagname'] in ignored_slice_attribute_names:
 584                 # If a slice already has a admin only role it was probably given to them by an
 585                 # admin, so we should ignore it.
 586                 ignored_slice_attribute_names.append(slice_tag['tagname'])
 587             else:
 588                 # If an existing slice attribute was not found in the request it should
 589                 # be removed
 590                 attribute_found=False
 591                 for requested_attribute in requested_slice_attributes:
 592                     if requested_attribute['name'] == slice_tag['tagname'] and \
 593                        requested_attribute['value'] == slice_tag['value']:
 594                         attribute_found=True
 595                         break
 596
 597             if not attribute_found and not append:
 598                 removed_slice_attributes.append(slice_tag)
 599
 600         # get attributes that should be added:
 601         for requested_attribute in requested_slice_attributes:
 602             # if the requested attribute wasn't found  we should add it
 603             if requested_attribute['name'] in valid_slice_attribute_names:
 604                 attribute_found = False
 605                 for existing_attribute in existing_slice_attributes:
 606                     if requested_attribute['name'] == existing_attribute['tagname'] and \
 607                        requested_attribute['value'] == existing_attribute['value']:
 608                         attribute_found=True
 609                         break
 610                 if not attribute_found:
 611                     added_slice_attributes.append(requested_attribute)
 612
 613
 614         # remove stale attributes
 615         for attribute in removed_slice_attributes:
 616             try:
 617                 self.driver.shell.DeleteSliceTag(attribute['slice_tag_id'])
 618             except Exception, e:
 619                 logger.warn('Failed to remove sliver attribute. name: %s, value: %s, node_id: %s\nCause:%s'\
 620                                 % (slice['name'], attribute['value'],  attribute.get('node_id'), str(e)))
 621
 622         # add requested_attributes
 623         for attribute in added_slice_attributes:
 624             try:
 625                 self.driver.shell.AddSliceTag(slice['name'], attribute['name'], attribute['value'], attribute.get('node_id', None))
 626             except Exception, e:
 627                 logger.warn('Failed to add sliver attribute. name: %s, value: %s, node_id: %s\nCause:%s'\
 628                                 % (slice['name'], attribute['value'],  attribute.get('node_id'), str(e)))
 629