Get rid of unused periodic_task

Currently Barbican is not using the periodic_task framework implemented
in oslo_service but implements its own mechanism based on the lower-
level thread group.

Change-Id: Idc69d61e07826923f3227aad6249252c3f739362

barbican/common/config.py

@@ -24,7 +24,6 @@ from oslo_config import cfg
 from oslo_log import log
 from oslo_middleware import cors
 from oslo_policy import opts as policy_opts
-from oslo_service import _options
 
 from barbican import i18n as u
 import barbican.version
@@ -256,7 +255,6 @@ def list_opts():
     yield None, common_opts
     yield None, host_opts
     yield None, db_opts
-    yield None, _options.eventlet_backdoor_opts
     yield db_opt_group, core_db_opts
     yield retry_opt_group, retry_opts
     yield queue_opt_group, queue_opts
@@ -294,8 +292,6 @@ def new_config():
     conf.register_opts(common_opts)
     conf.register_opts(host_opts)
     conf.register_opts(db_opts)
-    conf.register_opts(_options.eventlet_backdoor_opts)
-    conf.register_opts(_options.periodic_opts)
 
     conf.register_group(db_opt_group)
     conf.register_opts(core_db_opts, group=db_opt_group)

barbican/queue/retry_scheduler.py

@@ -19,7 +19,6 @@ Retry/scheduler classes and logic.
 import datetime
 import random
 
-from oslo_service import periodic_task
 from oslo_service import service
 
 from barbican.common import config
@@ -46,11 +45,9 @@ def _compute_next_periodic_interval():
 class PeriodicServer(service.Service):
     """Server to process retry and scheduled tasks.
 
-    This server is an Oslo periodic-task service (see
-    https://docs.openstack.org/oslo.service/latest/reference/periodic_task.html).
-    On a periodic basis, this server checks for tasks that need to be
-    retried, and then sends them up to the RPC queue for later
-    processing by a worker node.
+    This server is an Oslo service. This server runs a thread to periodically
+    check tasks that need to be retried, and then sends them up to the RPC
+    queue for later processing by a worker node.
     """
     def __init__(self, queue_resource=None):
         super(PeriodicServer, self).__init__()
@@ -80,7 +77,6 @@ class PeriodicServer(service.Service):
         LOG.info("Halting the PeriodicServer")
         super(PeriodicServer, self).stop(graceful=graceful)
 
-    @periodic_task.periodic_task
     def _check_retry_tasks(self):
         """Periodically check to see if tasks need to be scheduled.
 

etc/oslo-config-generator/barbican.conf

@@ -18,6 +18,5 @@ namespace = oslo.middleware.cors
 namespace = oslo.middleware.healthcheck
 namespace = oslo.middleware.http_proxy_to_wsgi
 namespace = oslo.policy
-namespace = oslo.service.periodic_task
 namespace = oslo.service.service
 namespace = oslo.versionedobjects