def expect_ha():
""" Determine if the unit expects to be in HA
Check juju goal-state if ha relation is expected, check for VIP or dns-ha
settings which indicate the unit should expect to be related to hacluster.
@returns boolean
"""
ha_related_units = []
try:
ha_related_units = list(expected_related_units(reltype='ha'))
except (NotImplementedError, KeyError):
pass
return len(ha_related_units) > 0 or config('vip') or config('dns-ha')
def expect_ha():
""" Determine if the unit expects to be in HA
Check juju goal-state if ha relation is expected, check for VIP or dns-ha
settings which indicate the unit should expect to be related to hacluster.
@returns boolean
"""
ha_related_units = []
try:
ha_related_units = list(expected_related_units(reltype='ha'))
except (NotImplementedError, KeyError):
pass
return len(ha_related_units) > 0 or config('vip') or config('dns-ha')
def _goal_state_achieved_for_relid(reltype, rid=None):
"""Check that the goal-state has been achieved for the reltype and relid.
If goal state is not available, then the function returns True.
Otherwise, as goal state (from Juju) replies with all the units for the
relation type, without respect for the relation id. i.e. normally, Juju is
a hierarchy of relation type -> relation id -> units, but goal state is
relation type -> units (where all the units across the relation ids are
grouped.
If the relid is None, then the relation_id for the hook is used (by the
library function related_units()).
Note this function checks a particular relation id for reaching goal state,
not all relation ids. To do that (with this function) do:
all(_goal_state_achieved_for_relid(reltype, rid)
for rid in relation_ids(reltype))
:param reltype: the relation type (e.g. 'cloud-compute')
:type reltype: str
:param rid: the relation id, or None for the default
:type rid: Union[str, None]
:returns: True if goal state is achieved, or not available
:rtype: bool
"""
try:
# There should always be one unit -- if not, this block KeyErrors and
# so the goal is false.
units_so_far = hookenv.related_units(relid=rid)
# goal state returns all the units by the relation type (in this
# case 'cloud-compute'). So we need to only check the ones with
# the same prefix e.g. nova-compute/0, nova-compute/1 vs
# nova-compute-b/0, etc if there were two separate relations to two
# nova-compute applications
all_units = list(
hookenv.expected_related_units(reltype=reltype))
prefix = units_so_far[0].split('/')[0]
target_units = [u for u in all_units if u.split('/')[0] == prefix]
return units_so_far == target_units
except (KeyError, IndexError):
# expected_related_units() can raise a KeyError in the case there are
# no units - in that case assume that the goal wasn't met
# if there are no units_so_far, then Index error is raised
return False
except NotImplementedError:
# Not implemented means that goal state is not available
pass
return True