fix: add timeout to apply/replace kubectl calls (#572)

pkg/utils/kube/kube.go

@@ -55,6 +55,11 @@ const (
 	HorizontalPodAutoscalerKind  = "HorizontalPodAutoscaler"
 )
 
+const (
+	// defaultKubectlRequestTimeout is the timeout value used when calling the 'apply' command of kubectl. The previous default was no timeout, which would allow apply operation to potentially run forever, thus leaking YAML files into /dev/shm until Pod restart.
+	defaultKubectlRequestTimeout = time.Hour * 1
+)
+
 type ResourceInfoProvider interface {
 	IsNamespaced(gk schema.GroupKind) (bool, error)
 }

pkg/utils/kube/resource_ops.go

@@ -175,6 +175,11 @@ func (k *kubectlResourceOperations) ReplaceResource(ctx context.Context, obj *un
 		if err != nil {
 			return err
 		}
+
+		// When calling the kubectl 'replace' command, it will run _without_ a timeout (as of this writing, May 2024):
+		// - If users are finding that 'replace' operations are running forever (and thus leaking manifest files into '/dev/shm'), one can enable 'force' via sync options or annotation, which will enable a default timeout of 5 minutes within the 'replace' kubectl call.
+		// - However, this guidance apply to replace options only (i.e. not apply).
+
 		return replaceOptions.Run(f)
 	})
 }
@@ -261,6 +266,14 @@ func (k *kubectlResourceOperations) ApplyResource(ctx context.Context, obj *unst
 		if err != nil {
 			return err
 		}
+
+		// If no timeout is specified (and thus an infinite wait), we will substitute a LONG default value.
+		// This allows enough time to complete for any valid, expected long running apply operations, while also preventing excessive leaks of resources into /dev/shm, due to operations that are likely never going to complete.
+		if applyOpts.DeleteOptions.Timeout == 0 {
+			// Yes, this is correct: Apply uses the 'DeleteOptions' struct to set the timeout val
+			applyOpts.DeleteOptions.Timeout = defaultKubectlRequestTimeout
+		}
+
 		return applyOpts.Run()
 	})
 }