Normalize NodeBalancer type annotation to lowercase for safety

Add automatic lowercase conversion for NodeBalancer type annotations to prevent typos and inconsistent casing. Update documentation to reflect that NodeBalancer types should always be specified in lowercase (e.g., `premium_40gb` instead of `premium_40GB`).

Author: komer3

cloud/linode/loadbalancers.go

@@ -762,6 +762,8 @@ func (l *loadbalancers) GetLoadBalancerTags(_ context.Context, clusterName strin
 func (l *loadbalancers) GetLinodeNBType(service *v1.Service) linodego.NodeBalancerPlanType {
 	typeStr, ok := service.GetAnnotations()[annotations.AnnLinodeNodeBalancerType]
 	if ok {
+		// For Safety - avoid typos and inconsistent casing
+		typeStr = strings.ToLower(typeStr)
 		switch linodego.NodeBalancerPlanType(typeStr) {
 		case linodego.NBTypeCommon: // need to add this because of the golint check
 			return linodego.NBTypeCommon

docs/configuration/annotations.md

@@ -38,7 +38,7 @@ The keys and the values in [annotations must be strings](https://kubernetes.io/d
 | `tags` | string | | A comma separated list of tags to be applied to the NodeBalancer instance |
 | `firewall-id` | int | | An existing Cloud Firewall ID to be attached to the NodeBalancer instance. See [Firewall Setup](firewall.md) |
 | `firewall-acl` | string | | The Firewall rules to be applied to the NodeBalancer. See [Firewall Configuration](#firewall-configuration) |
-| `nodebalancer-type` | string | | The type of NodeBalancer to create (options: common, premium, premium_40GB). See [NodeBalancer Types](#nodebalancer-type) |
+| `nodebalancer-type` | string | | The type of NodeBalancer to create (options: common, premium, premium_40gb). See [NodeBalancer Types](#nodebalancer-type). Note: NodeBalancer types should always be specified in lowercase. |
 | `enable-ipv6-ingress` | bool | `false` | When `true`, both IPv4 and IPv6 addresses will be included in the LoadBalancerStatus ingress |
 | `backend-ipv4-range` | string | | The IPv4 range from VPC subnet to be applied to the NodeBalancer backend. See [Nodebalancer VPC Configuration](#nodebalancer-vpc-configuration) |
 | `backend-vpc-name` | string | | VPC which is connected to the NodeBalancer backend. See [Nodebalancer VPC Configuration](#nodebalancer-vpc-configuration) |
@@ -123,7 +123,9 @@ metadata:
 ```
 
 ### NodeBalancer Type
-Linode supports nodebalancers of different types: common, premium, and premium_40GB. By default, nodebalancers of type common are provisioned. If an account is allowed to provision premium nodebalancers and one wants to use them, it can be achieved by specifying the annotation:
+Linode supports nodebalancers of different types: common, premium, and premium_40gb. By default, nodebalancers of type common are provisioned. If an account is allowed to provision premium nodebalancers and one wants to use them, it can be achieved by specifying the annotation:
+
+**Note:** NodeBalancer types should always be specified in lowercase. The controller will automatically convert uppercase values to lowercase for safety.
 ```yaml
 metadata:
   annotations:

docs/configuration/environment.md

@@ -46,7 +46,7 @@ The CCM supports the following flags:
 | `--load-balancer-type` | String | `nodebalancer` | Configures which type of load-balancing to use (options: nodebalancer, cilium-bgp) |
 | `--bgp-node-selector` | String | `""` | Node selector to use to perform shared IP fail-over with BGP |
 | `--ip-holder-suffix` | String | `""` | Suffix to append to the IP holder name when using shared IP fail-over with BGP |
-| `--default-nodebalancer-type` | String | `common` | Default type of NodeBalancer to create (options: common, premium, premium_40GB) |
+| `--default-nodebalancer-type` | String | `common` | Default type of NodeBalancer to create (options: common, premium, premium_40gb). Note: NodeBalancer types should always be specified in lowercase. |
 | `--nodebalancer-tags` | String (comma separated) |  | Linode tags to apply to all NodeBalancers |
 | `--nodebalancer-backend-ipv4-subnet` | String | `""` | ipv4 subnet to use for NodeBalancer backends |
 | `--nodebalancer-backend-ipv4-subnet-id` | Int | `""` | ipv4 subnet id to use for NodeBalancer backends |