Adjust default strategy for DaemonSet-like deployments

When emulating DaemonSets, we have antiaffinity rule that prevents 2
pods from running on the same host and we have no spare nodes to start
new pods, so we should do -1+1 update there.

Change-Id: I733d426d80e09aec015a05cc3324fcf7a2c8699c

fuel_ccp/deploy.py

@@ -101,6 +101,7 @@ def parse_role(component, topology, configmaps):
     affinity = templates.serialize_affinity(service, topology)
 
     replicas = CONF.replicas.get(service_name)
+    strategy = {'type': service.get('strategy', 'RollingUpdate')}
     if service.get("kind") == 'DaemonSet':
         LOG.warning("Deployment is being used instead of DaemonSet to support "
                     "updates")
@@ -112,10 +113,11 @@ def parse_role(component, topology, configmaps):
             raise RuntimeError("Replicas couldn't be specified for services "
                                "implemented using Kubernetes DaemonSet")
         replicas = len(set(topology[service_name]))
+        if strategy['type'] == 'RollingUpdate':
+            strategy['rollingUpdate'] = {'maxSurge': 0, 'maxUnavailable': 1}
     else:
         replicas = replicas or 1
 
-    strategy = service.get('strategy', 'RollingUpdate')
     obj = templates.serialize_deployment(service_name, cont_spec, affinity,
                                          replicas, component_name, strategy)
     yield [obj]

fuel_ccp/templates.py

@@ -290,6 +290,12 @@ def serialize_job(name, spec, component_name, app_name):
 
 def serialize_deployment(name, spec, affinity, replicas, component_name,
                          strategy):
+    if strategy['type'] == 'RollingUpdate':
+        strategy.setdefault("rollingUpdate", {
+            "maxSurge": 1,
+            "maxUnavailable": 0
+        })
+
     deployment = {
         "apiVersion": "extensions/v1beta1",
         "kind": "Deployment",
@@ -298,9 +304,7 @@ def serialize_deployment(name, spec, affinity, replicas, component_name,
         },
         "spec": {
             "replicas": replicas,
-            "strategy": {
-                "type": strategy
-            },
+            "strategy": strategy,
             "template": {
                 "metadata": {
                     "annotations": affinity,
@@ -315,13 +319,6 @@ def serialize_deployment(name, spec, affinity, replicas, component_name,
         }
     }
 
-    if strategy == 'RollingUpdate':
-        deployment['spec']['strategy'].update({
-            "rollingUpdate": {
-                "maxSurge": 1,
-                "maxUnavailable": 0
-            }
-        })
     return deployment