Fix IPv6 backend lint and docs wording

Author: komer3

cloud/linode/loadbalancers_test.go

@@ -4283,7 +4283,10 @@ func Test_buildLoadBalancerRequestPreservesVPCConfigForIPv6Backends(t *testing.T
 
 			client := linodego.NewClient(http.DefaultClient)
 			client.SetBaseURL(ts.URL)
-			lb := newLoadbalancers(&client, "us-west").(*loadbalancers)
+			lb, ok := newLoadbalancers(&client, "us-west").(*loadbalancers)
+			if !ok {
+				t.Fatal("type assertion failed")
+			}
 
 			fake.vpc[1] = &linodego.VPC{
 				ID:    1,

deploy/chart/values.yaml

@@ -108,8 +108,8 @@ tolerations:
 # This can also be controlled per-service using the "service.beta.kubernetes.io/linode-loadbalancer-enable-ipv6-ingress" annotation
 # enableIPv6ForLoadBalancers: true
 
-# Enable public IPv6 backend addresses for newly created non-VPC NodeBalancer services
-# Existing services are not migrated automatically, and all selected backend nodes must have public IPv6
+# Enable IPv6 backend addresses for NodeBalancer services
+# Existing services can be kept on IPv4 by setting service.beta.kubernetes.io/linode-loadbalancer-enable-ipv6-backends: "false", and all selected backend nodes must have the required IPv6 address
 # This can also be controlled per-service using the "service.beta.kubernetes.io/linode-loadbalancer-enable-ipv6-backends" annotation
 # enableIPv6ForNodeBalancerBackends: false
 

docs/configuration/loadbalancer.md

@@ -74,6 +74,7 @@ When IPv6 backends are enabled:
 - both VPC-backed and non-VPC-backed NodeBalancer services are affected
 - when VPC-backed NodeBalancers are enabled, CCM preserves the NodeBalancer VPC configuration instead of dropping it
 - enabling the global `--enable-ipv6-for-nodebalancer-backends` flag can migrate existing eligible NodeBalancer services from IPv4 to IPv6 backends during reconcile
+- to keep an existing Service on IPv4 while the global flag is enabled, set `service.beta.kubernetes.io/linode-loadbalancer-enable-ipv6-backends: "false"` on that Service
 - every selected backend node must have an IPv6 address in the currently selected backend path
 - the workload cluster and Service must be configured for dual-stack networking
 - reconciliation fails and CCM logs an error if a selected backend node does not have the required IPv6 address