From 4bdff5d6723af6afd2d39094d92166d6105e9c52 Mon Sep 17 00:00:00 2001
From: "patchback[bot]" <45432694+patchback[bot]@users.noreply.github.com>
Date: Wed, 11 Dec 2024 16:23:41 +0000
Subject: [PATCH] Make k8s_drain work when only one pod is present (#770)
 (#820)

This is a backport of PR #770 as merged into main (4c305e7).
SUMMARY
Fixes #769 .
k8s_drain was not checking if a pod has been deleted when there was only one pod on the node to be drained.
The list of pods, pods, was being "popped" before the first iteration of the while loop:
        pod = pods.pop()
        while (_elapsed_time() < wait_timeout or wait_timeout == 0) and pods:
When pods contains only one element, the while loop is skipped.


ISSUE TYPE


Bugfix Pull Request

COMPONENT NAME

k8s_drain
---
 .../770-fix-k8s-drain-doesnt-wait-for-single-pod.yaml       | 2 ++
 plugins/modules/k8s_drain.py                                | 6 ++++--
 2 files changed, 6 insertions(+), 2 deletions(-)
 create mode 100644 changelogs/fragments/770-fix-k8s-drain-doesnt-wait-for-single-pod.yaml

diff --git a/changelogs/fragments/770-fix-k8s-drain-doesnt-wait-for-single-pod.yaml b/changelogs/fragments/770-fix-k8s-drain-doesnt-wait-for-single-pod.yaml
new file mode 100644
index 0000000000..a063d79c81
--- /dev/null
+++ b/changelogs/fragments/770-fix-k8s-drain-doesnt-wait-for-single-pod.yaml
@@ -0,0 +1,2 @@
+bugfixes:
+  - k8s_drain - Fix k8s_drain does not wait for single pod (https://github.com/ansible-collections/kubernetes.core/issues/769).
diff --git a/plugins/modules/k8s_drain.py b/plugins/modules/k8s_drain.py
index d23c8212a8..6544553b0d 100644
--- a/plugins/modules/k8s_drain.py
+++ b/plugins/modules/k8s_drain.py
@@ -303,10 +303,10 @@ def _elapsed_time():
             return (datetime.now() - start).seconds
 
         response = None
-        pod = pods.pop()
+        pod = None
         while (_elapsed_time() < wait_timeout or wait_timeout == 0) and pods:
             if not pod:
-                pod = pods.pop()
+                pod = pods[-1]
             try:
                 response = self._api_instance.read_namespaced_pod(
                     namespace=pod[0], name=pod[1]
@@ -315,6 +315,7 @@ def _elapsed_time():
                     "name"
                 ):
                     pod = None
+                    del pods[-1]
                 time.sleep(wait_sleep)
             except ApiException as exc:
                 if exc.reason != "Not Found":
@@ -322,6 +323,7 @@ def _elapsed_time():
                         msg="Exception raised: {0}".format(exc.reason)
                     )
                 pod = None
+                del pods[-1]
             except Exception as e:
                 self._module.fail_json(msg="Exception raised: {0}".format(to_native(e)))
         if not pods: