apache / apache/cloudstack-kubernetes-provider

Unable to auto-scale Kubernetes cluster

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Description

Hi!

I am unable to auto-scale Kubernetes clusters. As I understand, it create a "cluster-autoscaler" deployment that decides whether to scale or not. However, it does not seem to work, since it logs multiple errors and warnings in the pod, even though it is a completely clean cluster.

Normal scaling seems to work just fine.

# Setup
A "default" CloudStack setup **4.18** running KVMs.

## Settings (relevant)
- Cloud kubernetes service enabled **true**
- Cloud kubernetes cluster experimental features enabled **true**
- Cloud kubernetes cluster max size **50**

The nodes uses the following service offering:
- 2 CPU x 2.05 Ghz
- 2048 MB memory
- 8 GB root disk

# Replicate
1. Create a new cluster using Kubernets 1.24 ISO found here:
http://download.cloudstack.org/cks/

2. Enable forced auto-scaling
Since the cluster starts with only one worker node, auto-scaling with 3-5 nodes should trigger an upscale (I assume)
![Screenshot from 2023-08-07 16-55-00](https://github.com/apache/cloudstack-kubernetes-provider/assets/26722370/9b92cc88-b107-42cb-8268-4ae3af25c1f6)

4. Check the logs for cluster-autoscaler in the Kubernetes cluster
Some notable entries:
```
E0807 14:41:30.317148 1 reflector.go:138] k8s.io/client-go/informers/factory.go:134: Failed to watch *v1.CSIDriver: failed to list *v1.CSIDriver: csidrivers.storage.k8s.io is forbidden: User "system:serviceaccount:kube-system:cluster-autoscaler" cannot list resource "csidrivers" in API group "storage.k8s.io" at the cluster scope

E0807 14:41:32.388828 1 reflector.go:138] k8s.io/client-go/informers/factory.go:134: Failed to watch *v1beta1.CSIStorageCapacity: failed to list *v1beta1.CSIStorageCapacity: csistoragecapacities.storage.k8s.io is forbidden: User "system:serviceaccount:kube-system:cluster-autoscaler" cannot list resource "csistoragecapacities" in API group "storage.k8s.io" at the cluster scope
```
Even though I have not edited anything myself (just a clean CKS cluster), I get these weird logs:

```
W0807 14:41:43.251280 1 clusterstate.go:590] Failed to get nodegroup for 6a4c91a3-9694-4596-9ddd-dc86e60136ff: Unable to find node 6a4c91a3-9694-4596-9ddd-dc86e60136ff in cluster

W0807 14:41:43.251361 1 clusterstate.go:590] Failed to get nodegroup for bd0b855f-6dc6-4678-9bea-b52329333024: Unable to find node bd0b855f-6dc6-4678-9bea-b52329333024 in cluster

I0807 14:57:06.667061 1 static_autoscaler.go:341] 2 unregistered nodes present
```
The IDs are correct in CloudStack

The entire log:
[logs-from-cluster-autoscaler-in-cluster-autoscaler-5bf887ddd8-hxg2g.log](https://github.com/apache/cloudstack-kubernetes-provider/files/12281530/logs-from-cluster-autoscaler-in-cluster-autoscaler-5bf887ddd8-hxg2g.log)

Please tell me if you need more logs to look at, or if I should try some other configuration.

Thanks!

Contributor guide

No contributing guide indexed for this repository

Research direction

Reproduce the issue with the CloudStack 4.18 setup, Kubernetes 1.24 ISO, and the cluster-autoscaler deployment described in the issue. Start by reviewing the cluster-autoscaler pod logs, especially the RBAC and unregistered-node warnings. Done means identifying the cause and restoring expected autoscaling without the reported errors.

Written by the indexing model from the issue text.

Assessment

Tech stack
kubernetes
Domain
cloud, infrastructure
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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