What happened?

A node that was NotReady was added to a LoadBalancer pool (using the OpenStack Cloud Controller Manager).
A LoadBalancer service (exposed on a NodePort) was not operational (but the ip/port was reachable and thus enabled by the external load balancer), because the node's networking was not yet fully operational.

What did you expect to happen?

I would have expected nodes to only be added to a load balancer pool when they are Ready (or when the NodeNetworkUnavailable condition is false).

How can we reproduce it (as minimally and precisely as possible)?

• Add a LoadBalancer Service
• Add a new Node that takes some time to get ready (e.g. by disabling the CNI DaemonSet on that node)
• The Node is added to the LoadBalancer service

Anything else we need to know?

Although the service controller code contains a nodeReadyPredicate, it appears to be unused. The ensureLoadBalancer function uses stableNodeSetPredicates, which do not include the nodeReadyPredicate.
Consequently, nodes that are NotReady are added to a load balancer pool even when the node's networking is not yet fully operational.

I suggest either adding the nodeReadyPredicate to the stableNodeSetPredicate or adding a nodeNetworkNotUnavailablePredicate, and checking whether the v1.NodeNetworkUnavailable condition is false.

I could create a pull request for this.

Kubernetes version

Server Version: v1.29.12

Cloud provider

OS version

$ cat /etc/os-release
NAME="Flatcar Container Linux by Kinvolk"
ID=flatcar
ID_LIKE=coreos
VERSION=3815.2.5
VERSION_ID=3815.2.5
BUILD_ID=2024-07-01-2356
SYSEXT_LEVEL=1.0
PRETTY_NAME="Flatcar Container Linux by Kinvolk 3815.2.5 (Oklo)"
ANSI_COLOR="38;5;75"
HOME_URL="https://flatcar.org/"
BUG_REPORT_URL="https://issues.flatcar.org"
FLATCAR_BOARD="amd64-usr"
CPE_NAME="cpe:2.3:o:flatcar-linux:flatcar_linux:3815.2.5:*:*:*:*:*:*:*"
$ uname -a
Linux xxx 6.1.96-flatcar #1 SMP PREEMPT_DYNAMIC Mon Jul  1 23:29:55 -00 2024 x86_64 AMD EPYC-Milan Processor AuthenticAMD GNU/Linux

Install tools

Container runtime (CRI) and version (if applicable)

Related plugins (CNI, CSI, ...) and versions (if applicable)