Fix waiting on StatefulSet scale down (#391)

Fix waiting on StatefulSet scale down

SUMMARY

When scaling a StatefulSet down to 0 replicas the wait will fail
because some properties of the status (readyReplicas, updatedReplicas)
will not exist. These are probably defined as omitempty in the API and
since the value is zero are not present in the response.

Fixes #203
ISSUE TYPE


Bugfix Pull Request

COMPONENT NAME

k8s_scale
ADDITIONAL INFORMATION

Reviewed-by: Gonéri Le Bouder <goneri@lebouder.net>

tests/integration/targets/k8s_scale/tasks/main.yml

@@ -341,6 +341,54 @@
           - scale_out.changed
           - scale_out.results | map(attribute='result.status.replicas') | list | unique == [2]
 
+    - name: Create a StatefulSet
+      kubernetes.core.k8s:
+        wait: yes
+        wait_timeout: "{{ k8s_wait_timeout | default(omit) }}"
+        definition:
+          apiVersion: apps/v1
+          kind: StatefulSet
+          metadata:
+            namespace: "{{ scale_namespace }}"
+            name: scale-set
+          spec:
+            replicas: 2
+            selector:
+              matchLabels:
+                app: foo
+            template:
+              metadata:
+                labels:
+                  app: foo
+              spec:
+                terminationGracePeriodSeconds: 10
+                containers:
+                  - image: busybox
+                    name: busybox
+                    command:
+                      - sleep
+                      - "600"
+      register: output
+
+    - assert:
+        that:
+          - output.result.status.replicas == 2
+
+    - name: Wait for StatefulSet to scale down to 0
+      kubernetes.core.k8s_scale:
+        kind: StatefulSet
+        api_version: apps/v1
+        name: scale-set
+        namespace: "{{ scale_namespace }}"
+        replicas: 0
+        wait: yes
+        wait_timeout: "{{ k8s_wait_timeout | default(omit) }}"
+      register: output
+
+    - assert:
+        that:
+          - output.result.status.replicas == 0
+
   always:
     - name: Remove namespace
       k8s: