Convert Memcached to work without HostNetwork=True

Memcached needs to be configured to listen to 0.0.0.0 in the Kolla
config for this to work -- this is OK because we're only exposing the
Memcached port internally to the cluster.  That still needs to be done.

I ran some tests and HostNetwork=True doesn't allow for the k8s
service discovery mechanism to work.  However, I also ran some tests
and a container with HostNetwork=True is still able to connect to
Memcached's service -- Kubernetes creates the illusion of an SDN using
iptables rules on the base node.  Thus, we're going to move faster on
the k8s side if we default to HostNetwork=false and use
HostNetwork=true when necessary (for example: Neutron).

Change-Id: I0858f78aac84c64e2640614b7e82f9c39de6daf7
Partially-implements: blueprint kolla-kubernetes-service-discovery
Partially-implements: blueprint remove-net-hostremove-net-host

services/memcached/memcached-pod.yml.j2

@@ -7,9 +7,8 @@ spec:
   template:
     metadata:
       labels:
-        service: memcached      
+        service: memcached
     spec:
-      hostNetwork: True
       containers:
         - image: "{{ memcached_image_full }}"
           name: memcached
@@ -19,6 +18,9 @@ spec:
           env:
             - name: KOLLA_CONFIG_STRATEGY
               value: {{ config_strategy }}
+          ports:
+            - containerPort: {{ memcached_port }}
+              name: memcached
       volumes:
         - name: memcached-config
           configMap:

services/memcached/memcached-service.yml.j2

@@ -3,7 +3,8 @@ kind: Service
 spec:
   ports:
     - port: {{ memcached_port }}
+      name: memcached
   selector:
-    name: memcached
+    service: memcached
 metadata:
    name: memcached