Fix waiting on StatefulSet scale down (ansible-collections#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 ansible-collections#203 ISSUE TYPE Bugfix Pull Request COMPONENT NAME k8s_scale ADDITIONAL INFORMATION Reviewed-by: Gonéri Le Bouder <goneri@lebouder.net>
Akasurde · Mar 11, 2022 · d68dec3 · d68dec3
1 parent 30e84fa
commit d68dec3
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diff --git a/changelogs/fragments/391-fix-statefulset-wait.yaml b/changelogs/fragments/391-fix-statefulset-wait.yaml
@@ -0,0 +1,2 @@
+bugfixes:
+  - k8s_scale - fix waiting on statefulset when scaled down to 0 replicas (https://github.com/ansible-collections/kubernetes.core/issues/203).
diff --git a/plugins/module_utils/common.py b/plugins/module_utils/common.py
@@ -633,15 +633,19 @@ def _daemonset_ready(daemonset):
             )
 
         def _statefulset_ready(statefulset):
+            # These may be None
+            updated_replicas = statefulset.status.updatedReplicas or 0
+            ready_replicas = statefulset.status.readyReplicas or 0
+
             return (
                 statefulset.status
                 and statefulset.spec.updateStrategy.type == "RollingUpdate"
                 and statefulset.status.observedGeneration
                 == (statefulset.metadata.generation or 0)
                 and statefulset.status.updateRevision
                 == statefulset.status.currentRevision
-                and statefulset.status.updatedReplicas == statefulset.spec.replicas
-                and statefulset.status.readyReplicas == statefulset.spec.replicas
+                and updated_replicas == statefulset.spec.replicas
+                and ready_replicas == statefulset.spec.replicas
                 and statefulset.status.replicas == statefulset.spec.replicas
             )
 

diff --git a/tests/integration/targets/k8s_scale/tasks/main.yml b/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: