k8s: bump golangci-lint to latest version

There was a change for nolint directives:
golangci/golangci-lint#3109 (comment)

And we are adding confidence of 0.8 in revive to
avoid false positives.

(cherry picked from commit bf5401e)

src/go/k8s/.golangci.yml

@@ -26,10 +26,11 @@ linters-settings:
   misspell:
     locale: US
   nolintlint:
-    allow-leading-space: true # don't require machine-readable nolint directives (i.e. with no leading space)
     allow-unused: false # report any unused nolint directives
     require-explanation: false # don't require an explanation for nolint directives
     require-specific: false # don't require nolint directives to be specific about which linter is being skipped
+  revive:
+    confidence: 0.8
 
 linters:
   # please, do not use `enable-all`: it's deprecated and will be removed soon.

src/go/k8s/apis/redpanda/v1alpha1/cluster_types.go

@@ -50,11 +50,12 @@ type RedpandaResourceRequirements struct {
 // * Is limited by 2Gi per core if requests.memory is set.
 //
 // Example:
-//    in: minimum requirement per core, 2GB
-//    in: Requests.Memory, 16GB
-//    => maxAllowedCores = 8
-//    if requestedCores == 8, set smp = 8 (with 2GB per core)
-//    if requestedCores == 4, set smp = 4 (with 4GB per core)
+//
+//	in: minimum requirement per core, 2GB
+//	in: Requests.Memory, 16GB
+//	=> maxAllowedCores = 8
+//	if requestedCores == 8, set smp = 8 (with 2GB per core)
+//	if requestedCores == 4, set smp = 4 (with 4GB per core)
 func (r *RedpandaResourceRequirements) RedpandaCPU() *resource.Quantity {
 	q := r.Redpanda.Cpu()
 	if q == nil || q.IsZero() {
@@ -257,17 +258,33 @@ type StorageSpec struct {
 // used as a external listener. This port is tight to the autogenerated
 // host port. The collision between Kafka external, Kafka internal,
 // Admin, Pandaproxy, Schema Registry and RPC port is checked in the webhook.
+// An optional endpointTemplate can be used to configure advertised addresses
+// for Kafka API and Pandaproxy, while it is disallowed for other listeners.
 type ExternalConnectivityConfig struct {
 	// Enabled enables the external connectivity feature
 	Enabled bool `json:"enabled,omitempty"`
 	// Subdomain can be used to change the behavior of an advertised
 	// KafkaAPI. Each broker advertises Kafka API as follows
-	// BROKER_ID.SUBDOMAIN:EXTERNAL_KAFKA_API_PORT.
+	// ENDPOINT.SUBDOMAIN:EXTERNAL_KAFKA_API_PORT.
 	// If Subdomain is empty then each broker advertises Kafka
 	// API as PUBLIC_NODE_IP:EXTERNAL_KAFKA_API_PORT.
 	// If TLS is enabled then this subdomain will be requested
 	// as a subject alternative name.
 	Subdomain string `json:"subdomain,omitempty"`
+	// EndpointTemplate is a Golang template string that allows customizing each
+	// broker advertised address.
+	// Redpanda uses the format BROKER_ID.SUBDOMAIN:EXTERNAL_KAFKA_API_PORT by
+	// default for advertised addresses. When an EndpointTemplate is
+	// provided, then the BROKER_ID part is replaced with the endpoint
+	// computed from the template.
+	// The following variables are available to the template:
+	// - Index: the Redpanda broker progressive number
+	// - HostIP: the ip address of the Node, as reported in pod status
+	//
+	// Common template functions from Sprig (http://masterminds.github.io/sprig/)
+	// are also available. The set of available functions is limited to hermetic
+	// functions because template application needs to be deterministic.
+	EndpointTemplate string `json:"endpointTemplate,omitempty"`
 	// The preferred address type to be assigned to the external
 	// advertised addresses. The valid types are ExternalDNS,
 	// ExternalIP, InternalDNS, InternalIP, and Hostname.
@@ -908,12 +925,14 @@ type TLSConfig struct {
 // Kafka API
 
 // GetPort returns API port
+//
 //nolint:gocritic // TODO KafkaAPI is now 81 bytes, consider a pointer
 func (k KafkaAPI) GetPort() int {
 	return k.Port
 }
 
 // GetTLS returns API TLSConfig
+//
 //nolint:gocritic // TODO KafkaAPI is now 81 bytes, consider a pointer
 func (k KafkaAPI) GetTLS() *TLSConfig {
 	return &TLSConfig{
@@ -925,6 +944,7 @@ func (k KafkaAPI) GetTLS() *TLSConfig {
 }
 
 // GetExternal returns API's ExternalConnectivityConfig
+//
 //nolint:gocritic // TODO KafkaAPI is now 81 bytes, consider a pointer
 func (k KafkaAPI) GetExternal() *ExternalConnectivityConfig {
 	return &k.External

src/go/k8s/apis/redpanda/v1alpha1/cluster_types_test.go

@@ -21,7 +21,7 @@ import (
 	"k8s.io/utils/pointer"
 )
 
-// nolint:funlen // this is ok for a test
+//nolint:funlen // this is ok for a test
 func TestRedpandaResourceRequirements(t *testing.T) {
 	type test struct {
 		name                string

src/go/k8s/apis/redpanda/v1alpha1/cluster_webhook.go

@@ -15,6 +15,7 @@ import (
 	"strconv"
 
 	cmmeta "github.com/jetstack/cert-manager/pkg/apis/meta/v1"
+	"github.com/redpanda-data/redpanda/src/go/k8s/pkg/utils"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
@@ -277,6 +278,12 @@ func (r *Cluster) validateAdminListeners() field.ErrorList {
 				r.Spec.Configuration.AdminAPI,
 				"bootstrap loadbalancer not available for http admin api"))
 	}
+	if externalAdmin != nil && externalAdmin.External.EndpointTemplate != "" {
+		allErrs = append(allErrs,
+			field.Invalid(field.NewPath("spec").Child("configuration").Child("adminApi"),
+				r.Spec.Configuration.AdminAPI,
+				"cannot provide an endpoint template for admin listener"))
+	}
 
 	// for now only one listener can have TLS to be backward compatible with v1alpha1 API
 	foundListenerWithTLS := false
@@ -306,6 +313,7 @@ func (r *Cluster) validateKafkaListeners() field.ErrorList {
 	}
 
 	var external *KafkaAPI
+	var externalIdx int
 	for i, p := range r.Spec.Configuration.KafkaAPI {
 		if p.External.Enabled {
 			if external != nil {
@@ -315,6 +323,7 @@ func (r *Cluster) validateKafkaListeners() field.ErrorList {
 						"only one kafka api listener can be marked as external"))
 			}
 			external = &r.Spec.Configuration.KafkaAPI[i]
+			externalIdx = i
 		}
 	}
 
@@ -357,10 +366,36 @@ func (r *Cluster) validateKafkaListeners() field.ErrorList {
 				r.Spec.Configuration.KafkaAPI,
 				"bootstrap port cannot be empty"))
 	}
+	//nolint:dupl // not identical
+	if external != nil && external.External.EndpointTemplate != "" {
+		if external.External.Subdomain == "" {
+			allErrs = append(allErrs,
+				field.Invalid(field.NewPath("spec").Child("configuration").Child("kafkaApi").Index(externalIdx).Child("external"),
+					external.External,
+					"endpointTemplate can only be used in combination with subdomain"))
+		}
+
+		err := checkValidEndpointTemplate(external.External.EndpointTemplate)
+		if err != nil {
+			log.Error(err, "Invalid endpoint template received", "template", external.External.EndpointTemplate)
+			allErrs = append(allErrs,
+				field.Invalid(field.NewPath("spec").Child("configuration").Child("kafkaApi").Index(externalIdx).Child("external").Child("endpointTemplate"),
+					external.External.EndpointTemplate,
+					fmt.Sprintf("template is invalid: %v", err)))
+		}
+	}
 
 	return allErrs
 }
 
+func checkValidEndpointTemplate(tmpl string) error {
+	// Using an example input to ensure that the template expression is allowed
+	data := utils.NewEndpointTemplateData(0, "1.2.3.4")
+	_, err := utils.ComputeEndpoint(tmpl, data)
+	return err
+}
+
+//nolint:funlen,gocyclo // it's a sequence of checks
 func (r *Cluster) validatePandaproxyListeners() field.ErrorList {
 	var allErrs field.ErrorList
 	var proxyExternal *PandaproxyAPI
@@ -412,6 +447,25 @@ func (r *Cluster) validatePandaproxyListeners() field.ErrorList {
 					r.Spec.Configuration.PandaproxyAPI[i],
 					"sudomain of external pandaproxy must be the same as kafka's"))
 		}
+		//nolint:dupl // not identical
+		if kafkaExternal != nil && proxyExternal.External.EndpointTemplate != "" {
+			if proxyExternal.External.Subdomain == "" {
+				allErrs = append(allErrs,
+					field.Invalid(field.NewPath("spec").Child("configuration").Child("pandaproxyApi").Index(i).Child("external"),
+						proxyExternal.External,
+						"endpointTemplate can only be used in combination with subdomain"))
+			}
+
+			err := checkValidEndpointTemplate(proxyExternal.External.EndpointTemplate)
+			if err != nil {
+				log.Error(err, "Invalid endpoint template received", "template", proxyExternal.External.EndpointTemplate)
+				allErrs = append(allErrs,
+					field.Invalid(field.NewPath("spec").Child("configuration").Child("pandaproxyApi").Index(i).
+						Child("external").Child("endpointTemplate"),
+						proxyExternal.External.EndpointTemplate,
+						fmt.Sprintf("template is invalid: %v", err)))
+			}
+		}
 	}
 
 	// for now only one listener can have TLS to be backward compatible with v1alpha1 API
@@ -510,6 +564,13 @@ func (r *Cluster) validateSchemaRegistryListener() field.ErrorList {
 				r.Spec.Configuration.SchemaRegistry.External,
 				"bootstrap loadbalancer not available for schema reigstry"))
 	}
+	if schemaRegistry.External.EndpointTemplate != "" {
+		allErrs = append(allErrs,
+			field.Invalid(field.NewPath("spec").Child("configuration").Child("schemaRegistry").Child("external").Child("endpointTemplate"),
+				r.Spec.Configuration.SchemaRegistry.External.EndpointTemplate,
+				"cannot provide an endpoint template for schema registry"))
+	}
+
 	return allErrs
 }