Add support for loadBalancerClass in LoadBalancer services

This adds a new configuration option `load_balancer_class` that allows
users to specify which load balancer provider should handle the service
when running multiple providers in the same cluster.

The setting can be configured globally via the OperatorConfiguration
CRD and will be applied to all LoadBalancer services (master, replica,
and connection pooler services).

Fixes #2600

docs/reference/operator_parameters.md

@@ -719,6 +719,13 @@ In the CRD-based configuration they are grouped under the `load_balancer` key.
   defines external traffic policy for load
   balancers. Allowed values are `Cluster` (default) and `Local`.
 
+* **load_balancer_class**
+  specifies the load balancer class to use for LoadBalancer services. This is
+  useful when running multiple load balancer providers in the same cluster,
+  allowing you to select which provider should handle the service. For example,
+  `service.k8s.aws/nlb` for AWS Network Load Balancer. When not set, the
+  cluster's default load balancer class is used.
+
 * **master_dns_name_format**
   defines the DNS name string template for the master load balancer cluster.
   The default is `{cluster}.{namespace}.{hostedzone}`, where `{cluster}` is

manifests/operatorconfiguration.crd.yaml

@@ -473,6 +473,9 @@ spec:
                   replica_legacy_dns_name_format:
                     type: string
                     default: "{cluster}-repl.{team}.{hostedzone}"
+                  load_balancer_class:
+                    type: string
+                    description: "LoadBalancerClass to use for LoadBalancer services"
               aws_or_gcp:
                 type: object
                 properties:

manifests/postgresql-operator-default-configuration.yaml

@@ -149,6 +149,7 @@ configuration:
     enable_replica_load_balancer: false
     enable_replica_pooler_load_balancer: false
     external_traffic_policy: "Cluster"
+    # load_balancer_class: "service.k8s.aws/nlb"
     master_dns_name_format: "{cluster}.{namespace}.{hostedzone}"
     # master_legacy_dns_name_format: "{cluster}.{team}.{hostedzone}"
     replica_dns_name_format: "{cluster}-repl.{namespace}.{hostedzone}"

pkg/apis/acid.zalan.do/v1/operator_configuration_type.go

@@ -147,6 +147,7 @@ type LoadBalancerConfiguration struct {
 	ReplicaDNSNameFormat            config.StringTemplate `json:"replica_dns_name_format,omitempty"`
 	ReplicaLegacyDNSNameFormat      config.StringTemplate `json:"replica_legacy_dns_name_format,omitempty"`
 	ExternalTrafficPolicy           string                `json:"external_traffic_policy" default:"Cluster"`
+	LoadBalancerClass               string                `json:"load_balancer_class,omitempty"`
 }
 
 // AWSGCPConfiguration defines the configuration for AWS

pkg/cluster/k8sres.go

@@ -2020,6 +2020,9 @@ func (c *Cluster) configureLoadBalanceService(serviceSpec *v1.ServiceSpec, sourc
 
 	c.logger.Debugf("final load balancer source ranges as seen in a service spec (not necessarily applied): %q", serviceSpec.LoadBalancerSourceRanges)
 	serviceSpec.ExternalTrafficPolicy = v1.ServiceExternalTrafficPolicyType(c.OpConfig.ExternalTrafficPolicy)
+	if c.OpConfig.LoadBalancerClass != "" {
+		serviceSpec.LoadBalancerClass = &c.OpConfig.LoadBalancerClass
+	}
 	serviceSpec.Type = v1.ServiceTypeLoadBalancer
 }
 

pkg/controller/operator_config.go

@@ -176,6 +176,7 @@ func (c *Controller) importConfigurationFromCRD(fromCRD *acidv1.OperatorConfigur
 	result.ReplicaDNSNameFormat = fromCRD.LoadBalancer.ReplicaDNSNameFormat
 	result.ReplicaLegacyDNSNameFormat = fromCRD.LoadBalancer.ReplicaLegacyDNSNameFormat
 	result.ExternalTrafficPolicy = util.Coalesce(fromCRD.LoadBalancer.ExternalTrafficPolicy, "Cluster")
+	result.LoadBalancerClass = fromCRD.LoadBalancer.LoadBalancerClass
 
 	// AWS or GCP config
 	result.WALES3Bucket = fromCRD.AWSGCP.WALES3Bucket

pkg/util/config/config.go

@@ -220,6 +220,7 @@ type Config struct {
 	StorageResizeMode                        string            `name:"storage_resize_mode" default:"pvc"`
 	EnableLoadBalancer                       *bool             `name:"enable_load_balancer"` // deprecated and kept for backward compatibility
 	ExternalTrafficPolicy                    string            `name:"external_traffic_policy" default:"Cluster"`
+	LoadBalancerClass                        string            `name:"load_balancer_class"`
 	MasterDNSNameFormat                      StringTemplate    `name:"master_dns_name_format" default:"{cluster}.{namespace}.{hostedzone}"`
 	MasterLegacyDNSNameFormat                StringTemplate    `name:"master_legacy_dns_name_format" default:"{cluster}.{team}.{hostedzone}"`
 	ReplicaDNSNameFormat                     StringTemplate    `name:"replica_dns_name_format" default:"{cluster}-repl.{namespace}.{hostedzone}"`