zuul-merger - only update podSpecTemplate to keep configured replicas…

… count

Also adds a scale up at beginging of the test suite and check that
we still have two replicas at the end of the test suite.

Change-Id: I19eee2a128ddfc1b189ebe1392d31f4726895628

controllers/zuul.go

@@ -471,7 +471,7 @@ func (r *SFController) EnsureZuulMerger(cfg *ini.File) bool {
 	if r.GetM(service, &current) {
 		if !utils.MapEquals(&current.Spec.Template.ObjectMeta.Annotations, &annotations) {
 			r.log.V(1).Info("zuul-merger configuration changed, rollout zuul-merger pods ...")
-			current.Spec = zm.DeepCopy().Spec
+			current.Spec.Template = *zm.Spec.Template.DeepCopy()
 			r.UpdateR(&current)
 			return false
 		}

roles/health-check/scale-resources/defaults/main.yaml

@@ -3,3 +3,6 @@ scaling_services:
   - name: zuul-executor
     kind: sts
     replicas: 2
+  - name: zuul-merger
+    kind: sts
+    replicas: 2

roles/health-check/zuul-components/tasks/main.yaml

@@ -39,10 +39,10 @@
   failed_when: "'running' not in item.state"
   loop: "{{ _components.json['executor'] }}"
 
-- name: Check if, at least, one Zuul Merger Instances Exists, fails otherwise
+- name: Check if, two Zuul Merger Instances Exist, fails otherwise
   ansible.builtin.fail:
-    msg: "Zuul Merger has no instances"
-  when: "_components.json['merger'] | length  == 0"
+    msg: "Zuul Merger must have 2 replicas"
+  when: "_components.json['merger'] | length != 2"
 
 - name: Check if Zuul Merger Components are Running
   ansible.builtin.fail: