Use context provided by request in rpc server

In the ml2 mechanism driver we used a pre-created RPC context object
instead of the context object provided by the call itself. That means
that all calls use the same request with the same request id, which
makes tracing calls harder. In one instance this also lead to the DB
connection of this object being broken, which rendered the context
unusable for all subsequent calls. To prevent all of this, we're now
using the context provided by the request.

asr1k_neutron_l3/plugins/ml2/drivers/mech_asr1k/rpc_api.py

@@ -14,7 +14,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from neutron_lib import context
 from neutron_lib import rpc as n_rpc
 from oslo_log import helpers as log_helpers
 from oslo_log import log
@@ -72,38 +71,37 @@ class ASR1KPluginCallback(object):
 
     def __init__(self):
         self.db = asr1k_db.get_db_plugin()
-        self.context = context.get_admin_context()
 
     @instrument.instrument()
-    def get_ports_with_extra_atts(self, rpc_context, ports, agent_id=None, host=None):
-        return self.db.get_ports_with_extra_atts(self.context, ports, host)
+    def get_ports_with_extra_atts(self, context, ports, agent_id=None, host=None):
+        return self.db.get_ports_with_extra_atts(context, ports, host)
 
     @instrument.instrument()
-    def get_extra_atts(self, rpc_context, ports, agent_id=None, host=None):
-        return self.db.get_extra_atts(self.context, ports, host)
+    def get_extra_atts(self, context, ports, agent_id=None, host=None):
+        return self.db.get_extra_atts(context, ports, host)
 
-    def get_orphaned_extra_atts(self, rpc_context, agent_id=None, host=None):
-        return self.db.get_orphaned_extra_atts(self.context, host=host)
+    def get_orphaned_extra_atts(self, context, agent_id=None, host=None):
+        return self.db.get_orphaned_extra_atts(context, host=host)
 
     @log_helpers.log_method_call
-    def delete_extra_atts(self, rpc_context, ports, agent_id=None, host=None):
+    def delete_extra_atts(self, context, ports, agent_id=None, host=None):
         LOG.debug("Deleting extra atts for ports {}".format(ports))
 
         for port_id in ports:
-            self.db.delete_extra_att(self.context, port_id, l2=True)
+            self.db.delete_extra_att(context, port_id, l2=True)
 
     @instrument.instrument()
-    def get_interface_ports(self, rpc_context, limit=None, offset=None, host=None):
-        ports = self.db.get_interface_ports(self.context, limit=limit,
+    def get_interface_ports(self, context, limit=None, offset=None, host=None):
+        ports = self.db.get_interface_ports(context, limit=limit,
                                             offset=offset, host=host)
 
         LOG.debug("ports len %s", len(ports))
 
         return ports
 
     @instrument.instrument()
-    def get_networks_with_asr1k_ports(self, rpc_context, limit=None, offset=None, host=None, networks=None):
-        return self.db.get_networks_with_asr1k_ports(self.context, limit, offset, host, networks)
+    def get_networks_with_asr1k_ports(self, context, limit=None, offset=None, host=None, networks=None):
+        return self.db.get_networks_with_asr1k_ports(context, limit, offset, host, networks)
 
     @instrument.instrument()
     def get_device_info(self, context, host):