Coverage for nova/scheduler/filters/utils.py: 100%

1# All Rights Reserved. 

2# 

3# Licensed under the Apache License, Version 2.0 (the "License"); you may 

4# not use this file except in compliance with the License. You may obtain 

5# a copy of the License at 

6# 

7# http://www.apache.org/licenses/LICENSE-2.0 

8# 

9# Unless required by applicable law or agreed to in writing, software 

10# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 

11# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 

12# License for the specific language governing permissions and limitations 

13# under the License. 

14 

15"""Bench of utility methods used by filters.""" 

16 

17import collections 

18 

19from oslo_log import log as logging 

20 

21LOG = logging.getLogger(__name__) 

22 

23 

24def aggregate_values_from_key(host_state, key_name): 

25 """Returns a set of values based on a metadata key for a specific host.""" 

26 aggrlist = host_state.aggregates 

27 return {aggr.metadata[key_name] 

28 for aggr in aggrlist 

29 if key_name in aggr.metadata 

30 } 

31 

32 

33def aggregate_metadata_get_by_host(host_state, key=None): 

34 """Returns a dict of all metadata based on a metadata key for a specific 

35 host. If the key is not provided, returns a dict of all metadata. 

36 """ 

37 aggrlist = host_state.aggregates 

38 metadata = collections.defaultdict(set) 

39 for aggr in aggrlist: 

40 if key is None or key in aggr.metadata: 

41 for k, v in aggr.metadata.items(): 

42 metadata[k].update(x.strip() for x in v.split(',')) 

43 return metadata 

44 

45 

46def validate_num_values(vals, default=None, cast_to=int, based_on=min): 

47 """Returns a correctly casted value based on a set of values. 

48 

49 This method is useful to work with per-aggregate filters, It takes 

50 a set of values then return the 'based_on'{min/max} converted to 

51 'cast_to' of the set or the default value. 

52 

53 Note: The cast implies a possible ValueError 

54 """ 

55 num_values = len(vals) 

56 if num_values == 0: 

57 return default 

58 

59 if num_values > 1: 

60 if based_on == min: 

61 LOG.info("%(num_values)d values found, " 

62 "of which the minimum value will be used.", 

63 {'num_values': num_values}) 

64 else: 

65 LOG.info("%(num_values)d values found, " 

66 "of which the maximum value will be used.", 

67 {'num_values': num_values}) 

68 return based_on([cast_to(val) for val in vals]) 

69 

70 

71def instance_uuids_overlap(host_state, uuids): 

72 """Tests for overlap between a host_state and a list of uuids. 

73 

74 Returns True if any of the supplied uuids match any of the instance.uuid 

75 values in the host_state. 

76 """ 

77 if isinstance(uuids, str): 

78 uuids = [uuids] 

79 set_uuids = set(uuids) 

80 # host_state.instances is a dict whose keys are the instance uuids 

81 host_uuids = set(host_state.instances.keys()) 

82 return bool(host_uuids.intersection(set_uuids))