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-rw-r--r--app/discover/link_finders/find_implicit_links.py128
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diff --git a/app/discover/link_finders/find_implicit_links.py b/app/discover/link_finders/find_implicit_links.py
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+###############################################################################
+# Copyright (c) 2017 Koren Lev (Cisco Systems), Yaron Yogev (Cisco Systems) #
+# and others #
+# #
+# All rights reserved. This program and the accompanying materials #
+# are made available under the terms of the Apache License, Version 2.0 #
+# which accompanies this distribution, and is available at #
+# http://www.apache.org/licenses/LICENSE-2.0 #
+###############################################################################
+from discover.link_finders.find_links import FindLinks
+
+
+class FindImplicitLinks(FindLinks):
+
+ def __init__(self):
+ super().__init__()
+ self.links = []
+ self.constraint_attributes = self.get_constraint_attributes()
+
+ def add_links(self):
+ self.log.info('adding implicit links')
+ self.get_existing_links()
+ self.get_transitive_closure()
+
+ def get_constraint_attributes(self) -> list:
+ attributes = set()
+ for c in self.inv.find({'environment': self.get_env()},
+ collection='clique_constraints'):
+ for a in c['constraints']:
+ attributes.add(a)
+ return list(attributes)
+
+ def get_existing_links(self):
+ self.log.info('fetching existing links')
+ existing_links = self.inv.find({'environment': self.get_env()},
+ collection='links')
+ for l in existing_links:
+ self.links.append({'pass': 0, 'link': l})
+
+ def constraints_match(self, link1, link2):
+ if 'attributes' not in link1 or 'attributes' not in link2:
+ return True
+ attr1 = link1['attributes']
+ attr2 = link2['attributes']
+ for a in self.constraint_attributes:
+ if a in attr1 and a in attr2 and attr1[a] != attr2[a]:
+ return False
+ return True
+
+ def links_match(self, start, dest):
+ if start['link_type'] == dest['link_type']:
+ return False # obviously we cannot make an implicit link of this
+ if start['source_id'] == dest['target_id']:
+ return False # avoid cyclic links
+ if not self.constraints_match(start, dest):
+ return False
+ return start['target_id'] == dest['source_id']
+
+ def add_matching_links(self, link, pass_no):
+ self.log.debug('looking for matches for link: {};{}'
+ .format(link['source_id'], link['target_id']))
+ matches = [l for l in self.links
+ if l['pass'] == 0 # take only original links
+ and self.links_match(link, l['link'])]
+ for l in matches:
+ implicit = self.add_implicit_link(link, l['link'])
+ self.links.append({'pass': pass_no, 'link': implicit})
+ return len(matches)
+
+ def get_link_constraint_attributes(self, link1, link2) -> dict:
+ attributes = {}
+ for a in self.constraint_attributes:
+ # constraints_match() verified the attribute values don't conflict
+ if a in link1.get('attributes', {}):
+ attributes[a] = link1['attributes'][a]
+ elif a in link2.get('attributes', {}):
+ attributes[a] = link2['attributes'][a]
+ return attributes
+
+ @staticmethod
+ def get_attr(attr, link1, link2):
+ if attr not in link1 and attr not in link2:
+ return None
+ if attr not in link1:
+ return link2[attr]
+ if attr not in link2 or link1[attr] == link2[attr]:
+ return link1[attr]
+ return None
+
+ def add_implicit_link(self, link1, link2):
+ link_type_from = link1['link_type'].split('-')[0]
+ link_type_to = link2['link_type'].split('-')[1]
+ link_type = '{}-{}'.format(link_type_from, link_type_to)
+ link_name = ''
+ state = 'down' \
+ if link1['state'] == 'down' or link2['state'] == 'down' \
+ else 'up'
+ link_weight = 0 # TBD
+ host = self.get_attr('host', link1, link2)
+ switch = self.get_attr('switch', link1, link2)
+ extra_attributes = self.get_link_constraint_attributes(link1, link2)
+ self.log.debug('adding implicit link: link type: {}, from: {}, to: {}'
+ .format(link_type,
+ link1['source_id'],
+ link2['target_id']))
+ implicit = self.create_link(self.get_env(),
+ link1['source'], link1['source_id'],
+ link2['target'], link2['target_id'],
+ link_type, link_name, state, link_weight,
+ host=host, switch=switch,
+ implicit=True,
+ extra_attributes=extra_attributes)
+ return implicit
+
+ def get_transitive_closure(self):
+ pass_no = 1
+ while True:
+ match_count = 0
+ last_pass_links = [l for l in self.links if l['pass'] == pass_no-1]
+ for l in last_pass_links:
+ match_count += self.add_matching_links(l['link'], pass_no)
+ self.log.info('Transitive closure pass #{}: '
+ 'found {} implicit links'
+ .format(pass_no, match_count))
+ if match_count == 0:
+ break
+ pass_no += 1
+ self.log.info('done adding implicit links')