add support for check_mode for modules k8s_scale and k8s_rollback (#255)

k8s_scale, k8s_rollback - add support for check_mode 

SUMMARY

closes #243 and #244

ISSUE TYPE


Bugfix Pull Request

COMPONENT NAME

k8s_scale
k8s_rollback
ADDITIONAL INFORMATION

Reviewed-by: Alina Buzachis <None>
Reviewed-by: None <None>
Reviewed-by: Mike Graves <mgraves@redhat.com>

changelogs/fragments/255-k8s_scale-k8s_rollback-add-support-for-check_mode.yml

@@ -0,0 +1,3 @@
+minor_changes:
+  - k8s_scale - add support for check_mode. (https://github.com/ansible-collections/kubernetes/core/issues/244).
+  - k8s_rollback - add support for check_mode. (https://github.com/ansible-collections/kubernetes/core/issues/243).

molecule/default/tasks/rollback.yml

@@ -8,18 +8,12 @@
       k8s:
         name: "{{ namespace }}"
         kind: Namespace
-        api_version: v1
-        apply: no
-      register: output
-
-    - name: show output
-      debug:
-        var: output
 
     - name: Create a deployment
       k8s:
         state: present
         wait: yes
+        wait_timeout: 30
         inline: &deploy
           apiVersion: apps/v1
           kind: Deployment
@@ -43,11 +37,7 @@
                     image: nginx:1.17
                     ports:
                       - containerPort: 80
-      register: output
 
-    - name: Show output
-      debug:
-        var: output
 
     - name: Crash the existing deployment
       k8s:
@@ -77,7 +67,47 @@
                     ports:
                       - containerPort: 80
       ignore_errors: yes
-      register: output
+      register: crash
+
+    - name: Assert that the Deployment failed
+      assert:
+        that:
+          - crash is failed
+
+    - name: Read the deployment
+      k8s_info:
+        kind: Deployment
+        name: nginx-deploy
+        namespace: "{{ namespace }}"
+      register: deployment
+
+    - set_fact:
+        failed_version: "{{ deployment.resources[0].metadata.annotations['deployment.kubernetes.io/revision'] }}"
+
+    - name: Rolling Back the crashed deployment (check mode)
+      k8s_rollback:
+        api_version: apps/v1
+        kind: Deployment
+        name: nginx-deploy
+        namespace: "{{ namespace }}"
+      register: result
+      check_mode: yes
+
+    - assert:
+        that:
+          - result is changed
+
+    - name: Read the deployment
+      k8s_info:
+        kind: Deployment
+        name: nginx-deploy
+        namespace: "{{ namespace }}"
+      register: deployment
+
+    - name: Validate that Rollback using check_mode did not changed the Deployment
+      assert:
+        that:
+          - failed_version == deployment.resources[0].metadata.annotations['deployment.kubernetes.io/revision']
 
     - name: Rolling Back the crashed deployment
       k8s_rollback:
@@ -85,12 +115,24 @@
         kind: Deployment
         name: nginx-deploy
         namespace: "{{ namespace }}"
-      when: output.failed
-      register: output
+      register: result
 
-    - name: Show output
-      debug:
-        var: output
+    - name: assert rollback is changed
+      assert:
+        that:
+          - result is changed
+
+    - name: Read the deployment once again
+      k8s_info:
+        kind: Deployment
+        name: nginx-deploy
+        namespace: "{{ namespace }}"
+      register: deployment
+
+    - name: Validate that Rollback changed the Deployment
+      assert:
+        that:
+          - failed_version | int + 1 == deployment.resources[0].metadata.annotations['deployment.kubernetes.io/revision'] | int
 
     - name: Create a DaemonSet
       k8s:
@@ -139,16 +181,12 @@
                   - name: varlibdockercontainers
                     hostPath:
                       path: /var/lib/docker/containers
-      register: output
-
-    - name: Show output
-      debug:
-        var: output
 
     - name: Crash the existing DaemonSet
       k8s:
         state: present
         wait: yes
+        wait_timeout: 30
         definition:
           apiVersion: apps/v1
           kind: DaemonSet
@@ -192,8 +230,44 @@
                   - name: varlibdockercontainers
                     hostPath:
                       path: /var/lib/docker/containers
-      ignore_errors: yes
-      register: output
+      register: crash
+      ignore_errors: true
+
+    - name: Assert that the Daemonset failed
+      assert:
+        that:
+          - crash is failed
+
+    - name: Read the crashed DaemonSet
+      k8s_info:
+        kind: DaemonSet
+        name: fluentd-elasticsearch
+        namespace: "{{ namespace }}"
+      register: result
+
+    - set_fact:
+        failed_version: "{{ result.resources[0].metadata.annotations['deprecated.daemonset.template.generation'] }}"
+
+    - name: Rolling Back the crashed DaemonSet (check_mode)
+      k8s_rollback:
+        api_version: apps/v1
+        kind: DaemonSet
+        name: fluentd-elasticsearch
+        namespace: "{{ namespace }}"
+      register: result
+      check_mode: yes
+
+    - name: Read the DaemonSet
+      k8s_info:
+        kind: DaemonSet
+        name: fluentd-elasticsearch
+        namespace: "{{ namespace }}"
+      register: result
+
+    - name: Validate that Rollback using check_mode did not changed the DaemonSet version
+      assert:
+        that:
+          - failed_version == result.resources[0].metadata.annotations['deprecated.daemonset.template.generation']
 
     - name: Rolling Back the crashed DaemonSet
       k8s_rollback:
@@ -201,12 +275,24 @@
         kind: DaemonSet
         name: fluentd-elasticsearch
         namespace: "{{ namespace }}"
-      when: output.failed
-      register: output
+      register: result
 
-    - name: Show output
-      debug:
-        var: output
+    - name: assert rollback is changed
+      assert:
+        that:
+          - result is changed
+
+    - name: Read the DaemonSet
+      k8s_info:
+        kind: DaemonSet
+        name: fluentd-elasticsearch
+        namespace: "{{ namespace }}"
+      register: result
+
+    - name: Validate that Rollback changed the Daemonset version
+      assert:
+        that:
+          - failed_version | int + 1 == result.resources[0].metadata.annotations['deprecated.daemonset.template.generation'] | int
 
   always:
     - name: Delete {{ namespace }} namespace

molecule/default/tasks/scale.yml

@@ -45,6 +45,68 @@
         field_selectors:
           - status.phase=Running
 
+    - name: Scale the deployment (check_mode)
+      k8s_scale:
+        api_version: apps/v1
+        kind: Deployment
+        name: scale-deploy
+        namespace: "{{ scale_namespace }}"
+        replicas: 0
+        wait: yes
+      register: scale_down
+      check_mode: true
+
+    - name: Get pods in scale-deploy
+      k8s_info:
+        kind: Pod
+        label_selectors:
+          - app=scale-deploy
+        namespace: "{{ scale_namespace }}"
+        field_selectors:
+          - status.phase=Running
+      register: scale_down_deploy_pods
+      ignore_errors: true
+      until: scale_down_deploy_pods.resources | length == 0
+      retries: 6
+      delay: 5
+
+    - name: Ensure the deployment did not changed and pods are still running
+      assert:
+        that:
+          - scale_down is changed
+          - scale_down_deploy_pods.resources | length > 0
+
+    - name: Scale the deployment (check_mode) once again - validate idempotency
+      k8s_scale:
+        api_version: apps/v1
+        kind: Deployment
+        name: scale-deploy
+        namespace: "{{ scale_namespace }}"
+        replicas: 0
+        wait: yes
+      register: scale_down
+      check_mode: true
+
+    - name: Get pods in scale-deploy
+      k8s_info:
+        kind: Pod
+        label_selectors:
+          - app=scale-deploy
+        namespace: "{{ scale_namespace }}"
+        field_selectors:
+          - status.phase=Running
+      register: scale_down_deploy_pods
+      ignore_errors: true
+      until: scale_down_deploy_pods.resources | length == 0
+      retries: 6
+      delay: 5
+
+    - name: Ensure the deployment did not changed and pods are still running
+      assert:
+        that:
+          - scale_down is changed
+          - scale_down_deploy_pods.resources | length > 0
+
     - name: Scale the deployment
       k8s_scale:
         api_version: apps/v1
@@ -76,6 +138,22 @@
           - '"duration" in scale_down'
           - scale_down.diff
 
+    - name: Scale the deployment once again (idempotency)
+      k8s_scale:
+        api_version: apps/v1
+        kind: Deployment
+        name: scale-deploy
+        namespace: "{{ scale_namespace }}"
+        replicas: 0
+        wait: yes
+      register: scale_down_idempotency
+      diff: true
+
+    - name: Ensure that scale down did not took effect
+      assert:
+        that:
+          - scale_down_idempotency is not changed
+
     - name: Reapply the earlier deployment
       k8s:
         definition:

plugins/modules/k8s_rollback.py

@@ -115,11 +115,13 @@ def execute_module(module, k8s_ansible_mixin):
         module.params["field_selectors"],
     )
 
+    changed = False
     for resource in resources["resources"]:
         result = perform_action(module, k8s_ansible_mixin, resource)
+        changed = result["changed"] or changed
         results.append(result)
 
-    module.exit_json(**{"changed": True, "rollback_info": results})
+    module.exit_json(**{"changed": changed, "rollback_info": results})
 
 
 def perform_action(module, k8s_ansible_mixin, resource):
@@ -143,6 +145,13 @@ def perform_action(module, k8s_ansible_mixin, resource):
     prev_managed_resource = get_previous_revision(
         managed_resources["resources"], current_revision
     )
+    if not prev_managed_resource:
+        warn = "No rollout history found for resource %s/%s" % (
+            module.params["kind"],
+            resource["metadata"]["name"],
+        )
+        result = {"changed": False, "warnings": [warn]}
+        return result
 
     if module.params["kind"] == "Deployment":
         del prev_managed_resource["spec"]["template"]["metadata"]["labels"][
@@ -174,22 +183,24 @@ def perform_action(module, k8s_ansible_mixin, resource):
         api_target = "daemonsets"
         content_type = "application/strategic-merge-patch+json"
 
-    rollback = k8s_ansible_mixin.client.request(
-        "PATCH",
-        "/apis/{0}/namespaces/{1}/{2}/{3}".format(
-            module.params["api_version"],
-            module.params["namespace"],
-            api_target,
-            module.params["name"],
-        ),
-        body=resource_patch,
-        content_type=content_type,
-    )
+    rollback = resource
+    if not module.check_mode:
+        rollback = k8s_ansible_mixin.client.request(
+            "PATCH",
+            "/apis/{0}/namespaces/{1}/{2}/{3}".format(
+                module.params["api_version"],
+                module.params["namespace"],
+                api_target,
+                module.params["name"],
+            ),
+            body=resource_patch,
+            content_type=content_type,
+        ).to_dict()
 
     result = {"changed": True}
     result["method"] = "patch"
     result["body"] = resource_patch
-    result["resources"] = rollback.to_dict()
+    result["resources"] = rollback
     return result
 
 

plugins/modules/k8s_scale.py

@@ -236,7 +236,7 @@ def execute_module(
             module.exit_json(warning=warn, **return_attributes)
 
     for existing in existing_items:
-        if module.params["kind"] == "job":
+        if module.params["kind"].lower() == "job":
             existing_count = existing.spec.parallelism
         elif hasattr(existing.spec, "replicas"):
             existing_count = existing.spec.replicas
@@ -271,22 +271,25 @@ def execute_module(
             continue
 
         if existing_count != replicas:
-            if not module.check_mode:
-                if module.params["kind"] == "job":
-                    existing.spec.parallelism = replicas
-                    result = resource.patch(existing.to_dict()).to_dict()
+            if module.params["kind"].lower() == "job":
+                existing.spec.parallelism = replicas
+                result = {"changed": True}
+                if module.check_mode:
+                    result["result"] = existing.to_dict()
                 else:
-                    result = scale(
-                        module,
-                        k8s_ansible_mixin,
-                        resource,
-                        existing,
-                        replicas,
-                        wait,
-                        wait_time,
-                        wait_sleep,
-                    )
-                    changed = changed or result["changed"]
+                    result["result"] = resource.patch(existing.to_dict()).to_dict()
+            else:
+                result = scale(
+                    module,
+                    k8s_ansible_mixin,
+                    resource,
+                    existing,
+                    replicas,
+                    wait,
+                    wait_time,
+                    wait_sleep,
+                )
+                changed = changed or result["changed"]
         else:
             name = existing.metadata.name
             namespace = existing.metadata.namespace
@@ -342,25 +345,34 @@ def scale(
 
     existing = resource.get(name=name, namespace=namespace)
 
-    try:
-        resource.scale.patch(body=scale_obj)
-    except Exception as exc:
-        module.fail_json(msg="Scale request failed: {0}".format(exc))
-
-    k8s_obj = resource.get(name=name, namespace=namespace).to_dict()
-    match, diffs = k8s_ansible_mixin.diff_objects(existing.to_dict(), k8s_obj)
     result = dict()
-    result["result"] = k8s_obj
+    if module.check_mode:
+        k8s_obj = copy.deepcopy(existing.to_dict())
+        k8s_obj["spec"]["replicas"] = replicas
+        match, diffs = k8s_ansible_mixin.diff_objects(existing.to_dict(), k8s_obj)
+        if wait:
+            result["duration"] = 0
+        result["result"] = k8s_obj
+    else:
+        try:
+            resource.scale.patch(body=scale_obj)
+        except Exception as exc:
+            module.fail_json(msg="Scale request failed: {0}".format(exc))
+
+        k8s_obj = resource.get(name=name, namespace=namespace).to_dict()
+        result["result"] = k8s_obj
+        if wait and not module.check_mode:
+            success, result["result"], result["duration"] = k8s_ansible_mixin.wait(
+                resource, scale_obj, wait_sleep, wait_time
+            )
+            if not success:
+                module.fail_json(msg="Resource scaling timed out", **result)
+
+    match, diffs = k8s_ansible_mixin.diff_objects(existing.to_dict(), k8s_obj)
     result["changed"] = not match
     if module._diff:
         result["diff"] = diffs
 
-    if wait:
-        success, result["result"], result["duration"] = k8s_ansible_mixin.wait(
-            resource, scale_obj, wait_sleep, wait_time
-        )
-        if not success:
-            module.fail_json(msg="Resource scaling timed out", **result)
     return result