Trim length for custom lb name for ALBs

Author: bnutt

docs/guide/ingress/annotations.md

@@ -157,7 +157,7 @@ Traffic Listening can be controlled with following annotations:
 ## Traffic Routing
 Traffic Routing can be controlled with following annotations:
 
-- <a name="load-balancer-name">`alb.ingress.kubernetes.io/load-balancer-name`</a> specifies the custom name to use for the load balancer.
+- <a name="load-balancer-name">`alb.ingress.kubernetes.io/load-balancer-name`</a> specifies the custom name to use for the load balancer. Name longer than 32 characters will be trimmed.
 
  !!!note "Merge Behavior"
  `name` is exclusive across all Ingresses in an IngressGroup.

pkg/ingress/model_build_load_balancer.go

@@ -6,9 +6,10 @@ import (
 "encoding/hex"
 "fmt"
 "regexp"
-"sigs.k8s.io/aws-load-balancer-controller/pkg/deploy/tracking"
 "strings"
 
+"sigs.k8s.io/aws-load-balancer-controller/pkg/deploy/tracking"
+
 awssdk "github.com/aws/aws-sdk-go/aws"
 ec2sdk "github.com/aws/aws-sdk-go/service/ec2"
 "github.com/google/go-cmp/cmp"
@@ -97,6 +98,10 @@ func (t *defaultModelBuildTask) buildLoadBalancerName(_ context.Context, scheme
 }
 if len(explicitNames) == 1 {
 name, _ := explicitNames.PopAny()
+// The name of the loadbalancer can only have up to 32 characters
+if len(name) > 32 {
+name = name[:32]
+}
 return name, nil
 }
 if len(explicitNames) > 1 {

pkg/ingress/model_build_load_balancer_test.go

@@ -3,14 +3,15 @@ package ingress
 import (
 "context"
 "errors"
+"testing"
+
 awssdk "github.com/aws/aws-sdk-go/aws"
 "github.com/stretchr/testify/assert"
 networking "k8s.io/api/networking/v1beta1"
 metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 "k8s.io/apimachinery/pkg/util/sets"
 "sigs.k8s.io/aws-load-balancer-controller/pkg/annotations"
 "sigs.k8s.io/aws-load-balancer-controller/pkg/model/elbv2"
-"testing"
 )
 
 func Test_defaultModelBuildTask_buildLoadBalancerCOIPv4Pool(t *testing.T) {
@@ -557,6 +558,29 @@ func Test_defaultModelBuildTask_buildLoadBalancerName(t *testing.T) {
 },
 want: "foo",
 },
+{
+name: "trim name annotation",
+fields: fields{
+ingGroup: Group{
+ID: GroupID{Namespace: "awesome-ns", Name: "ing-1"},
+Members: []ClassifiedIngress{
+{
+Ing: &networking.Ingress{
+ObjectMeta: metav1.ObjectMeta{
+Namespace: "awesome-ns",
+Name: "ing-1",
+Annotations: map[string]string{
+"alb.ingress.kubernetes.io/load-balancer-name": "bazbazfoofoobazbazfoofoobazbazfoo",
+},
+},
+},
+},
+},
+},
+scheme: elbv2.LoadBalancerSchemeInternetFacing,
+},
+want: "bazbazfoofoobazbazfoofoobazbazfo",
+},
 {
 name: "name annotation on single ingress only",
 fields: fields{