From c91e951eaebd823be6ad34478eba9fd50e6a631d Mon Sep 17 00:00:00 2001
From: Antonio Muniz <amuniz@users.noreply.github.com>
Date: Thu, 19 Dec 2024 17:43:12 +0100
Subject: [PATCH] Avoid NPE on informers (#1630)

I found out when working on a CloudBees proprietary feature that
`KubernetesCloud#readResolve` is not always called on deserialization.
I think this will not happen in OSS, but let's stay on the safe side and
initialize the field before using it.
---
 .../plugins/kubernetes/KubernetesCloud.java        | 14 ++++++++++----
 .../kubernetes/watch/PodStatusEventHandler.java    |  4 +++-
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesCloud.java b/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesCloud.java
index 037887e47..09e2bb3f6 100644
--- a/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesCloud.java
+++ b/src/main/java/org/csanchez/jenkins/plugins/kubernetes/KubernetesCloud.java
@@ -172,7 +172,7 @@ public class KubernetesCloud extends Cloud implements PodTemplateGroup {
      * namespace -> informer
      * Use to watch pod events per namespace.
      */
-    private transient Map<String, SharedIndexInformer<Pod>> informers = new ConcurrentHashMap<>();
+    private transient volatile Map<String, SharedIndexInformer<Pod>> informers = new ConcurrentHashMap<>();
 
     @DataBoundConstructor
     public KubernetesCloud(String name) {
@@ -1306,9 +1306,6 @@ private Object readResolve() {
         if (containerCap != null && containerCap == 0) {
             containerCap = null;
         }
-        if (informers == null) {
-            informers = new ConcurrentHashMap<>();
-        }
         return this;
     }
 
@@ -1321,6 +1318,15 @@ public Cloud reconfigure(@NonNull StaplerRequest req, JSONObject form) throws De
     }
 
     public void registerPodInformer(KubernetesSlave node) {
+        // even having readResolve initializing informers is not enough, there are some special cases where XStream will
+        // not call it, so let us make sure it is initialized before using
+        if (informers == null) {
+            synchronized (this) {
+                if (informers == null) {
+                    informers = new ConcurrentHashMap<>();
+                }
+            }
+        }
         informers.computeIfAbsent(node.getNamespace(), (n) -> {
             KubernetesClient client;
             try {
diff --git a/src/main/java/org/csanchez/jenkins/plugins/kubernetes/watch/PodStatusEventHandler.java b/src/main/java/org/csanchez/jenkins/plugins/kubernetes/watch/PodStatusEventHandler.java
index cac846b50..694adc690 100644
--- a/src/main/java/org/csanchez/jenkins/plugins/kubernetes/watch/PodStatusEventHandler.java
+++ b/src/main/java/org/csanchez/jenkins/plugins/kubernetes/watch/PodStatusEventHandler.java
@@ -50,7 +50,9 @@ private String formatPodStatus(PodCondition c, String phase, StringBuilder sb) {
             // not interesting
             return "";
         }
-        String formatted = String.format("%n\tPod [%s][%s] %s", phase, c.getReason(), c.getMessage());
+        String message = c.getMessage();
+        String formatted =
+                String.format("%n\tPod [%s][%s] %s", phase, c.getReason(), message != null ? message : "No message");
         return sb.indexOf(formatted) == -1 ? formatted : "";
     }