[Release-1.27] - SyncLoadBalancerFailed when using a very long (yet valid) service name

[brandond]

Backport fix for SyncLoadBalancerFailed when using a very long (yet valid) service name

• SyncLoadBalancerFailed when using a very long (yet valid) service name #10537

[fmoral2]

Validated on Version:

-$  k3s version v1.27.16+k3s-8c79522e (8c79522e)

Environment Details

Infrastructure
Cloud EC2 instance

Node(s) CPU architecture, OS, and Version:
PRETTY_NAME="Ubuntu 22.04.1 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"

Cluster Configuration:
1 node server

Steps to validate the fix

1. Install k3s
2. Create a lb service with a very long name yet valid in the range of 63 chars

apiVersion: v1
kind: Service
metadata:
  name: a-service-with-a-very-veeeeeery-long-yet-valid-name
spec:
  selector:
    app.kubernetes.io/name: MyApp
  ports:
    - protocol: TCP
      port: 80
  type: LoadBalancer

3. Validate that the service is created and working as expected
4. Validate pods

Reproduction Issue:

~$  k apply -f ldservicelongnameyetvalid.yaml


 $ journalctl -xeu k3s.service -f | grep "Error syncing load balancer"

Aug 09 12:35:20 ip  k3s[1803]: I0809 12:35:20.548326    1803 event.go:389] "Event occurred" object="default/a-service-with-a-very-veeeeeery-long-yet-valid-name" fieldPath="" kind="Service" apiVersion="v1" type="Warning" reason="SyncLoadBalancerFailed" message="Error syncing load balancer: failed to ensure load balancer: failed to create kube-system/svclb-a-service-with-a-very-veeeeeery-long-yet-valid-name-1c1eaccc apps/v1, Kind=DaemonSet for  default/a-service-with-a-very-veeeeeery-long-yet-valid-name: DaemonSet.apps \"svclb-a-service-with-a-very-veeeeeery-long-yet-valid-name-1c1eaccc\" is invalid: [spec.selector.matchLabels: Invalid value: \"svclb-a-service-with-a-very-veeeeeery-long-yet-valid-name-1c1eaccc\": must be no more than 63 characters, spec.template.labels: Invalid value: \"svclb-a-service-with-a-very-veeeeeery-long-yet-valid-name-1c1eaccc\": must be no more than 63 characters]"

Validation Results:

 
~$  k apply -f ldservicelongnameyetvalid.yaml


$ k get pods -A
 
kube-system   svclb-a-service-with-a-very-veeeeeery-long-yet-valid-n-1b8rd5s9   0/1     Pending     0          78s