If you’re encountering the following error when trying to apply a ScaledObject using the kubectl apply command:

kubectl apply -f nginx-scaledobject.yaml

And receive an error like:

Error from server (Timeout): error when applying patch: {"metadata":{"annotations":{"kubectl.kubernetes.io/last-applied-configuration":"{\"apiVersion\":\"keda.sh/v1alpha1\",\"kind\":\"ScaledObject\",\"metadata\":{\"annotations\":{},\"name\":\"nginx-scaledobject\",\"namespace\":\"default\"},\"spec\":{\"cooldownPeriod\":300,\"maxReplicaCount\":2,\"minReplicaCount\":1,\"pollingInterval\":3,\"scaleTargetRef\":{\"name\":\"nginx-deploy\"},\"triggers\":[{\"metadata\":{\"type\":\"Utilization\",\"value\":\"90\"},\"type\":\"cpu\"}]}}\n"}},"spec":{"maxReplicaCount":2}} to: Resource: "keda.sh/v1alpha1, Resource=scaledobjects", GroupVersionKind: "keda.sh/v1alpha1, Kind=ScaledObject" Name: "nginx-scaledobject", Namespace: "default" for: "nginx-scaledobject.yaml": error when patching "nginx-scaledobject.yaml": Timeout: request did not complete within requested timeout - context deadline exceeded.

Root cause

This issue commonly occurs when the KEDA admission webhook is not reachable by the Kubernetes control plane due to a network connectivity issue, typically on port 9443, which the webhook listens on.

Solution (For Managed Kubernetes Services)

Step 1: Enable Debug Logging on the Webhook This helps confirm whether the request is reaching the webhook.

Option A: If KEDA was installed via Helm:

Update your values.yaml file:

webhooks:
  level: debug

Then upgrade your Helm release:

helm upgrade <release-name> kedacore/keda -n keda -f values.yaml

Option B: If KEDA was installed manually (without Helm):

Edit the webhook deployment:

kubectl edit deployment keda-admission-webhooks -n keda

Add or update the arguments to include:

args:
  - "--zap-log-level=debug"

Step 2: Check Webhook Logs To confirm if the webhook is receiving the request:

kubectl logs -l app=keda-admission-webhooks -n keda

If no logs appear when you run kubectl apply, it means the webhook pod is not being reached.

Step 3: Check Network Connectivity Ensure port 9443 is open between:

• The Kubernetes control plane (where kubectl apply runs)

• The nodes hosting the keda-admission-webhooks pod

This often involves configuring firewall rules or security groups to allow traffic from the control plane IP range to the node IP range on port 9443.

Final Test:

After opening port 9443, try applying your ScaledObject again:

kubectl apply -f nginx-scaledobject.yaml

If the webhook logs now show activity and the resource is created or properly rejected, the issue is resolved.