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