def execute(self, method_name, params):
"""Execute the given method on the handler.
Checks to make sure the method is valid and allowed perform executing
the method.
"""
if method_name in self._meta.allowed_methods:
try:
method = getattr(self, method_name)
except AttributeError:
raise HandlerNoSuchMethodError(method_name)
else:
# Handler methods are predominantly transactional and thus
# blocking/synchronous. Genuinely non-blocking/asynchronous
# methods must out themselves explicitly.
if IAsynchronous.providedBy(method):
# The @asynchronous decorator will DTRT.
return method(params)
else:
# This is going to block and hold a database connection so
# we limit its concurrency.
return concurrency.webapp.run(
deferToDatabase, transactional(method), params)
else:
raise HandlerNoSuchMethodError(method_name)
def query(self, system_id, context):
"""Performs the power query action for `system_id`."""
exc_info = None, None, None
for waiting_time in self.wait_time:
try:
# Power queries are predominantly transactional and thus
# blocking/synchronous. Genuinely non-blocking/asynchronous
# methods must out themselves explicitly.
if IAsynchronous.providedBy(self.power_query):
# The @asynchronous decorator will DTRT.
state = yield self.power_query(system_id, context)
else:
state = yield deferToThread(
self.power_query, system_id, context
)
except PowerFatalError:
raise # Don't retry.
except PowerError:
exc_info = sys.exc_info()
# Wait before retrying.
yield pause(waiting_time, self.clock)
else:
returnValue(state)
else:
raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
def execute(self, method_name, params):
"""Execute the given method on the handler.
Checks to make sure the method is valid and allowed perform executing
the method.
"""
if method_name in self._meta.allowed_methods:
try:
method = getattr(self, method_name)
except AttributeError:
raise HandlerNoSuchMethodError(method_name)
else:
# Handler methods are predominantly transactional and thus
# blocking/synchronous. Genuinely non-blocking/asynchronous
# methods must out themselves explicitly.
if IAsynchronous.providedBy(
method
) or asyncio.iscoroutinefunction(method):
# Running in the io thread so clear RBAC now.
rbac.clear()
# Reload the user from the database.
d = concurrency.webapp.run(
deferToDatabase,
transactional(self.user.refresh_from_db),
)
d.addCallback(lambda _: ensureDeferred(method(params)))
return d
else:
@wraps(method)
@transactional
def prep_user_execute(params):
# Clear RBAC and reload the user to ensure that
# its up to date. `rbac.clear` must be done inside
# the thread because it uses thread locals internally.
rbac.clear()
self.user.refresh_from_db()
# Perform the work in the database.
return self._call_method_track_queries(
method_name, method, params
)
# Force the name of the function to include the handler
# name so the debug logging is useful.
prep_user_execute.__name__ = "%s.%s" % (
self.__class__.__name__,
method_name,
)
# This is going to block and hold a database connection so
# we limit its concurrency.
return concurrency.webapp.run(
deferToDatabase, prep_user_execute, params
)
else:
raise HandlerNoSuchMethodError(method_name)
def perform_power(self, power_func, state_desired, system_id, context):
"""Provides the logic to perform the power actions.
:param power_func: Function used to change the power state of the
node. Typically this will be `self.power_on` or `self.power_off`.
:param state_desired: The desired state for this node to be in,
typically "on" or "off".
:param system_id: The node's system ID.
"""
state = "unknown"
exc_info = None, None, None
for waiting_time in self.wait_time:
# Try to change state.
try:
# Power methods are predominantly transactional and thus
# blocking/synchronous. Genuinely non-blocking/asynchronous
# methods must out themselves explicitly.
if IAsynchronous.providedBy(power_func):
# The @asynchronous decorator will DTRT.
yield power_func(system_id, context)
else:
yield deferToThread(power_func, system_id, context)
except PowerFatalError:
raise # Don't retry.
except PowerError:
exc_info = sys.exc_info()
# Wait before retrying.
yield pause(waiting_time, self.clock)
else:
# LP:1768659 - If the power driver isn't queryable(manual)
# checking the power state will always fail.
if not self.queryable:
return
# Wait before checking state.
yield pause(waiting_time, self.clock)
# Try to get power state.
try:
# Power queries are predominantly transactional and thus
# blocking/synchronous. Genuinely non-blocking/asynchronous
# methods must out themselves explicitly.
if IAsynchronous.providedBy(self.power_query):
# The @asynchronous decorator will DTRT.
state = yield self.power_query(system_id, context)
else:
state = yield deferToThread(self.power_query,
system_id, context)
except PowerFatalError:
raise # Don't retry.
except PowerError:
exc_info = sys.exc_info()
else:
# If state is now the correct state, done.
if state == state_desired:
return
if exc_info == (None, None, None):
# No error found, so communication to the BMC is good, state must
# have not changed in the elapsed time. That is the only reason we
# should make it this far.
raise PowerError(
"Failed to power %s. BMC never transitioned from %s to %s." %
(system_id, state, state_desired))
else:
# Report the last error.
raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
