From 7767535426b29fc14461083528b0d15493a3262e Mon Sep 17 00:00:00 2001
From: Brooks Garrett <brooks@respond-software.com>
Date: Fri, 28 Sep 2018 23:25:04 -0400
Subject: [PATCH] Respect Allocation IDs

---
 .../k8s.io/legacy-cloud-providers/aws/aws.go  | 19 ++++++++++++++---
 .../aws/aws_loadbalancer.go                   | 21 ++++++++++++++-----
 2 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/staging/src/k8s.io/legacy-cloud-providers/aws/aws.go b/staging/src/k8s.io/legacy-cloud-providers/aws/aws.go
index 07f0bc064cb..59b21bffe6e 100644
--- a/staging/src/k8s.io/legacy-cloud-providers/aws/aws.go
+++ b/staging/src/k8s.io/legacy-cloud-providers/aws/aws.go
@@ -23,6 +23,7 @@ import (
 	"io"
 	"net"
 	"path"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
@@ -44,9 +45,9 @@ import (
 	"github.com/aws/aws-sdk-go/service/kms"
 	"github.com/aws/aws-sdk-go/service/sts"
 	"gopkg.in/gcfg.v1"
+	"k8s.io/api/core/v1"
 	"k8s.io/klog"
 
-	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
@@ -199,6 +200,11 @@ const ServiceAnnotationLoadBalancerHCTimeout = "service.beta.kubernetes.io/aws-l
 // service to specify, in seconds, the interval between health checks.
 const ServiceAnnotationLoadBalancerHCInterval = "service.beta.kubernetes.io/aws-load-balancer-healthcheck-interval"
 
+// ServiceAnnotationLoadBalancerEIPAllocations is the annotation used on the
+// service to specify a comma separated list of EIP allocations to use as
+// static IP addresses for the NLB. Only supported on elbv2 (NLB)
+const ServiceAnnotationLoadBalancerEIPAllocations = "service.beta.kubernetes.io/aws-load-balancer-eip-allocations"
+
 // Event key when a volume is stuck on attaching state when being attached to a volume
 const volumeAttachmentStuck = "VolumeAttachmentStuck"
 
@@ -3281,9 +3287,16 @@ func (c *Cloud) findELBSubnets(internalELB bool) ([]string, error) {
 		continue
 	}
 
+	var azNames []string
+	for key := range subnetsByAZ {
+		azNames = append(azNames, key)
+	}
+
+	sort.Strings(azNames)
+
 	var subnetIDs []string
-	for _, subnet := range subnetsByAZ {
-		subnetIDs = append(subnetIDs, aws.StringValue(subnet.SubnetId))
+	for _, key := range azNames {
+		subnetIDs = append(subnetIDs, aws.StringValue(subnetsByAZ[key].SubnetId))
 	}
 
 	return subnetIDs, nil
diff --git a/staging/src/k8s.io/legacy-cloud-providers/aws/aws_loadbalancer.go b/staging/src/k8s.io/legacy-cloud-providers/aws/aws_loadbalancer.go
index 3d6b50840d7..349e5a05de9 100644
--- a/staging/src/k8s.io/legacy-cloud-providers/aws/aws_loadbalancer.go
+++ b/staging/src/k8s.io/legacy-cloud-providers/aws/aws_loadbalancer.go
@@ -132,9 +132,17 @@ func (c *Cloud) ensureLoadBalancerv2(namespacedName types.NamespacedName, loadBa
 			createRequest.Scheme = aws.String("internal")
 		}
 
+		var allocationIDs []string
+		if eipList, present := annotations[ServiceAnnotationLoadBalancerEIPAllocations]; present {
+			allocationIDs = strings.Split(eipList, ",")
+			if len(allocationIDs) != len(subnetIDs) {
+				return nil, fmt.Errorf("Error creating load balancer: Must have same number of EIP AllocationIDs (%d) and SubnetIDs (%d)", len(allocationIDs), len(subnetIDs))
+			}
+		}
+
 		// We are supposed to specify one subnet per AZ.
 		// TODO: What happens if we have more than one subnet per AZ?
-		createRequest.SubnetMappings = createSubnetMappings(subnetIDs)
+		createRequest.SubnetMappings = createSubnetMappings(subnetIDs, allocationIDs)
 
 		for k, v := range tags {
 			createRequest.Tags = append(createRequest.Tags, &elbv2.Tag{
@@ -1347,12 +1355,15 @@ func elbListenersAreEqual(actual, expected *elb.Listener) bool {
 	return true
 }
 
-func createSubnetMappings(subnetIDs []string) []*elbv2.SubnetMapping {
+func createSubnetMappings(subnetIDs []string, allocationIDs []string) []*elbv2.SubnetMapping {
 	response := []*elbv2.SubnetMapping{}
 
-	for _, id := range subnetIDs {
-		// Ignore AllocationId for now
-		response = append(response, &elbv2.SubnetMapping{SubnetId: aws.String(id)})
+	for index, id := range subnetIDs {
+		sm := &elbv2.SubnetMapping{SubnetId: aws.String(id)}
+		if len(allocationIDs) > 0 {
+			sm.AllocationId = aws.String(allocationIDs[index])
+		}
+		response = append(response, sm)
 	}
 
 	return response