resolve hairpinning (#268)

* resolve hairpinning

* added docs

* fix lint

* fix lint

* remove ip from ingress

* removed ip from ingress

* lint fix

docs/load-balancers.md

@@ -37,3 +37,7 @@ The annotations are listed below. Please note that all annotations listed below
 | `node-count` | int | 1 | Number of LoadBalancer nodes to have. Only odd numbers are supported. |
 | `create` | `true` or `false` | `true` | This is used to determine whether or not to create a Vultr loadbalancer |
 | `label` | string | | Custom label for the Vultr Loadbalancer rather than the default generated name |
+| `hostname` | string | | Custom domain to be used for the load balancer. Ex: `example.vultr.com`
+
+
+

go.mod

@@ -3,6 +3,7 @@ module github.com/vultr/vultr-cloud-controller-manager
 go 1.21
 
 require (
+ github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2
  github.com/spf13/pflag v1.0.5
  github.com/vultr/govultr/v3 v3.8.1
  github.com/vultr/metadata v1.1.0
@@ -21,7 +22,6 @@ require (
  github.com/Azure/go-ansiterm v0.0.0-20230124172434-306776ec8161 // indirect
  github.com/NYTimes/gziphandler v1.1.1 // indirect
  github.com/antlr/antlr4/runtime/Go/antlr/v4 v4.0.0-20230305170008-8188dc5388df // indirect
- github.com/asaskevich/govalidator v0.0.0-20230301143203-a9d515a09cc2 // indirect
  github.com/beorn7/perks v1.0.1 // indirect
  github.com/blang/semver/v4 v4.0.0 // indirect
  github.com/cenkalti/backoff/v4 v4.2.1 // indirect

vultr/loadbalancers.go

@@ -8,6 +8,7 @@ import (
  "strconv"
  "strings"
 
+ "github.com/asaskevich/govalidator"
  "github.com/vultr/govultr/v3"
  "github.com/vultr/metadata"
  v1 "k8s.io/api/core/v1"
@@ -51,6 +52,9 @@ const (
  // annoVultrLBBackendProtocol backend protocol
  annoVultrLBBackendProtocol = "service.beta.kubernetes.io/vultr-loadbalancer-backend-protocol"
 
+ // annoVultrHostname is the hostname used for VLB to prevent hairpinning
+ annoVultrHostname = "service.beta.kubernetes.io/vultr-loadbalancer-hostname"
+
  annoVultrHealthCheckPath = "service.beta.kubernetes.io/vultr-loadbalancer-healthcheck-path"
  annoVultrHealthCheckProtocol = "service.beta.kubernetes.io/vultr-loadbalancer-healthcheck-protocol"
  annoVultrHealthCheckPort = "service.beta.kubernetes.io/vultr-loadbalancer-healthcheck-port"
@@ -116,11 +120,25 @@ func (l *loadbalancers) GetLoadBalancer(ctx context.Context, _ string, service *
 
  enabledIPv6 := checkEnabledIPv6(service)
  var ingress []v1.LoadBalancerIngress
+ hostname := lb.Label //nolint
 
- ingress = append(ingress, v1.LoadBalancerIngress{Hostname: lb.Label, IP: lb.IPV4})
+ // Check if hostname annotation is blank and set if not
+ if _, ok := service.Annotations[annoVultrHostname]; ok {
+ if service.Annotations[annoVultrHostname] != "" {
+ if govalidator.IsDNSName(service.Annotations[annoVultrHostname]) {
+ hostname = service.Annotations[annoVultrHostname]
+ } else {
+ return nil, true, fmt.Errorf("hostname %s is not a valid DNS name", service.Annotations[annoVultrHostname])
+ }
+ klog.Infof("setting hostname for loadbalancer to: %s", hostname)
+ ingress = append(ingress, v1.LoadBalancerIngress{Hostname: hostname})
+ }
+ } else {
+ ingress = append(ingress, v1.LoadBalancerIngress{Hostname: hostname, IP: lb.IPV4})
 
- if enabledIPv6 {
- ingress = append(ingress, v1.LoadBalancerIngress{Hostname: lb.Label, IP: lb.IPV6})
+ if enabledIPv6 {
+ ingress = append(ingress, v1.LoadBalancerIngress{Hostname: hostname, IP: lb.IPV6})
+ }
  }
 
  return &v1.LoadBalancerStatus{
@@ -194,10 +212,24 @@ func (l *loadbalancers) EnsureLoadBalancer(ctx context.Context, clusterName stri
  enabledIPv6 := checkEnabledIPv6(service)
  var ingress []v1.LoadBalancerIngress
 
- ingress = append(ingress, v1.LoadBalancerIngress{Hostname: lb2.Label, IP: lb2.IPV4})
+ hostname := lb2.Label //nolint
+ // Check if hostname annotation is blank and set if not
+ if _, ok := service.Annotations[annoVultrHostname]; ok {
+ if service.Annotations[annoVultrHostname] != "" {
+ if govalidator.IsDNSName(service.Annotations[annoVultrHostname]) {
+ hostname = service.Annotations[annoVultrHostname]
+ } else {
+ return nil, fmt.Errorf("hostname %s is not a valid DNS name", service.Annotations[annoVultrHostname])
+ }
+ klog.Infof("setting hostname for loadbalancer to: %s", hostname)
+ ingress = append(ingress, v1.LoadBalancerIngress{Hostname: hostname})
+ }
+ } else {
+ ingress = append(ingress, v1.LoadBalancerIngress{IP: lb2.IPV4})
 
- if enabledIPv6 {
- ingress = append(ingress, v1.LoadBalancerIngress{Hostname: lb2.Label, IP: lb2.IPV6})
+ if enabledIPv6 {
+ ingress = append(ingress, v1.LoadBalancerIngress{IP: lb2.IPV6})
+ }
  }
 
  return &v1.LoadBalancerStatus{
@@ -220,6 +252,9 @@ func (l *loadbalancers) EnsureLoadBalancer(ctx context.Context, clusterName stri
 
  // Set the Vultr VLB ID annotation
  if _, ok := service.Annotations[annoVultrLoadBalancerID]; !ok {
+ if service.Annotations == nil {
+ service.Annotations = make(map[string]string)
+ }
  service.Annotations[annoVultrLoadBalancerID] = lb.ID
  if err = l.GetKubeClient(); err != nil {
  return nil, fmt.Errorf("failed to get kubeclient to update service: %s", err)