def convergence_remove_server_from_group(log, transaction_id, server_id,
replace, purge, group, state):
"""
Remove a specific server from the group, optionally decrementing the
desired capacity.
The server may just be scheduled for deletion, or it may be evicted from
the group by removing otter-specific metdata from the server.
:param log: A bound logger
:param bytes trans_id: The transaction id for this operation.
:param bytes server_id: The id of the server to be removed.
:param bool replace: Should the server be replaced?
:param bool purge: Should the server be deleted from Nova?
:param group: The scaling group to remove a server from.
:type group: :class:`~otter.models.interface.IScalingGroup`
:param state: The current state of the group.
:type state: :class:`~otter.models.interface.GroupState`
:return: The updated state.
:rtype: Effect of :class:`~otter.models.interface.GroupState`
:raise: :class:`CannotDeleteServerBelowMinError` if the server cannot
be deleted without replacement, and :class:`ServerNotFoundError` if
there is no such server to be deleted.
"""
effects = [_is_server_in_group(group, server_id)]
if not replace:
effects.append(_can_scale_down(group, server_id))
# the (possibly) two checks can happen in parallel, but we want
# ServerNotFoundError to take precedence over
# CannotDeleteServerBelowMinError
both_checks = yield parallel_all_errors(effects)
for is_error, result in both_checks:
if is_error:
reraise(*result)
# Remove the server
if purge:
eff = set_nova_metadata_item(server_id, *DRAINING_METADATA)
else:
eff = Effect(
EvictServerFromScalingGroup(log=log,
transaction_id=transaction_id,
scaling_group=group,
server_id=server_id))
yield Effect(
TenantScope(
retry_effect(eff, retry_times(3), exponential_backoff_interval(2)),
group.tenant_id))
if not replace:
yield do_return(assoc_obj(state, desired=state.desired - 1))
else:
yield do_return(state)
def convergence_remove_server_from_group(
log, transaction_id, server_id, replace, purge, group, state):
"""
Remove a specific server from the group, optionally decrementing the
desired capacity.
The server may just be scheduled for deletion, or it may be evicted from
the group by removing otter-specific metdata from the server.
:param log: A bound logger
:param bytes trans_id: The transaction id for this operation.
:param bytes server_id: The id of the server to be removed.
:param bool replace: Should the server be replaced?
:param bool purge: Should the server be deleted from Nova?
:param group: The scaling group to remove a server from.
:type group: :class:`~otter.models.interface.IScalingGroup`
:param state: The current state of the group.
:type state: :class:`~otter.models.interface.GroupState`
:return: The updated state.
:rtype: Effect of :class:`~otter.models.interface.GroupState`
:raise: :class:`CannotDeleteServerBelowMinError` if the server cannot
be deleted without replacement, and :class:`ServerNotFoundError` if
there is no such server to be deleted.
"""
effects = [_is_server_in_group(group, server_id)]
if not replace:
effects.append(_can_scale_down(group, server_id))
# the (possibly) two checks can happen in parallel, but we want
# ServerNotFoundError to take precedence over
# CannotDeleteServerBelowMinError
both_checks = yield parallel_all_errors(effects)
for is_error, result in both_checks:
if is_error:
reraise(*result)
# Remove the server
if purge:
eff = set_nova_metadata_item(server_id, *DRAINING_METADATA)
else:
eff = Effect(
EvictServerFromScalingGroup(log=log,
transaction_id=transaction_id,
scaling_group=group,
server_id=server_id))
yield Effect(TenantScope(
retry_effect(eff, retry_times(3), exponential_backoff_interval(2)),
group.tenant_id))
if not replace:
yield do_return(assoc_obj(state, desired=state.desired - 1))
else:
yield do_return(state)
def add_event(event, admin_tenant_id, region, log):
"""
Add event to cloud feeds
"""
event, error, timestamp, event_tenant_id, event_id = sanitize_event(event)
req = prepare_request(request_format, event, error, timestamp, region, event_tenant_id, event_id)
eff = retry_effect(
publish_autoscale_event(req, log=log),
compose_retries(lambda f: (not f.check(APIError) or f.value.code < 400 or f.value.code >= 500), retry_times(5)),
exponential_backoff_interval(2),
)
return Effect(TenantScope(tenant_id=admin_tenant_id, effect=eff))
def as_effect(self):
"""Produce a :obj:`Effect` to delete a server."""
eff = retry_effect(
delete_and_verify(self.server_id), can_retry=retry_times(3),
next_interval=exponential_backoff_interval(2))
def report_success(result):
return StepResult.RETRY, [
ErrorReason.String(
'must re-gather after deletion in order to update the '
'active cache')]
return eff.on(success=report_success)
def as_effect(self):
"""Produce a :obj:`Effect` to delete a server."""
eff = retry_effect(
delete_and_verify(self.server_id), can_retry=retry_times(3),
next_interval=exponential_backoff_interval(2))
def report_success(result):
return StepResult.RETRY, [
ErrorReason.String(
'must re-gather after deletion in order to update the '
'active cache')]
return eff.on(success=report_success)
def test_retry_effect(self):
"""
:func:`retry_effect` takes an effect and returns an :obj:`Effect` of
:obj:`Retry`, with a :obj:`ShouldDelayAndRetry` as the should_retry
callable.
"""
can_retry = lambda f: True
next_interval = lambda f: 1
eff = retry_effect(STUB, can_retry, next_interval)
self.assertEqual(
eff,
Effect(
Retry(effect=STUB,
should_retry=ShouldDelayAndRetry(
can_retry=can_retry, next_interval=next_interval))))
def test_retry_effect(self):
"""
:func:`retry_effect` takes an effect and returns an :obj:`Effect` of
:obj:`Retry`, with a :obj:`ShouldDelayAndRetry` as the should_retry
callable.
"""
can_retry = lambda f: True
next_interval = lambda f: 1
eff = retry_effect(STUB, can_retry, next_interval)
self.assertEqual(
eff,
Effect(Retry(
effect=STUB,
should_retry=ShouldDelayAndRetry(can_retry=can_retry,
next_interval=next_interval))))
def add_event(event, admin_tenant_id, region, log):
"""
Add event to cloud feeds
"""
event, error, timestamp, event_tenant_id, event_id = sanitize_event(event)
req = prepare_request(request_format, event, error, timestamp, region,
event_tenant_id, event_id)
eff = retry_effect(
publish_autoscale_event(req, log=log),
compose_retries(
lambda f: (not f.check(APIError) or
f.value.code < 400 or
f.value.code >= 500),
retry_times(5)),
exponential_backoff_interval(2))
return Effect(TenantScope(tenant_id=admin_tenant_id, effect=eff))
def _is_server_in_group(group, server_id):
"""
Given a group and server ID, determines if the server is a member of
the group. If it isn't, it raises a :class:`ServerNotFoundError`.
"""
try:
response, server_info = yield Effect(
TenantScope(
retry_effect(get_server_details(server_id), retry_times(3), exponential_backoff_interval(2)),
group.tenant_id,
)
)
except NoSuchServerError:
raise ServerNotFoundError(group.tenant_id, group.uuid, server_id)
group_id = group_id_from_metadata(get_in(("server", "metadata"), server_info, {}))
if group_id != group.uuid:
raise ServerNotFoundError(group.tenant_id, group.uuid, server_id)
def _is_server_in_group(group, server_id):
"""
Given a group and server ID, determines if the server is a member of
the group. If it isn't, it raises a :class:`ServerNotFoundError`.
"""
try:
response, server_info = yield Effect(
TenantScope(
retry_effect(get_server_details(server_id), retry_times(3),
exponential_backoff_interval(2)),
group.tenant_id))
except NoSuchServerError:
raise ServerNotFoundError(group.tenant_id, group.uuid, server_id)
group_id = group_id_from_metadata(
get_in(('server', 'metadata'), server_info, {}))
if group_id != group.uuid:
raise ServerNotFoundError(group.tenant_id, group.uuid, server_id)
def _retry(eff):
"""Retry an effect with a common policy."""
return retry_effect(
eff, retry_times(5), exponential_backoff_interval(2))
def _retry(eff):
"""Retry an effect with a common policy."""
return retry_effect(eff, retry_times(5), exponential_backoff_interval(2))