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✨ Create only one nat gateway per AZ #5602

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115 changes: 59 additions & 56 deletions controlplane/eks/controllers/awsmanagedcontrolplane_controller_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -551,71 +551,74 @@ func mockedCallsForMissingEverything(ec2Rec *mocks.MockEC2APIMockRecorder, subne
eipAllocationID := strconv.Itoa(1234 + subnetIndex)
natGatewayID := fmt.Sprintf("nat-%d", subnetIndex+1)

ec2Rec.AllocateAddress(context.TODO(), gomock.Eq(&ec2.AllocateAddressInput{
Domain: ec2types.DomainTypeVpc,
TagSpecifications: []ec2types.TagSpecification{
{
ResourceType: ec2types.ResourceTypeElasticIp,
Tags: []ec2types.Tag{
{
Key: aws.String("Name"),
Value: aws.String("test-cluster-eip-common"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/cluster/test-cluster"),
Value: aws.String("owned"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/role"),
Value: aws.String("common"),
// We only expect to create NAT gateways for the public subnet AZ used by the private subnet
if subnet.ID == "my-managed-subnet-pub1" {
ec2Rec.AllocateAddress(context.TODO(), gomock.Eq(&ec2.AllocateAddressInput{
Domain: ec2types.DomainTypeVpc,
TagSpecifications: []ec2types.TagSpecification{
{
ResourceType: ec2types.ResourceTypeElasticIp,
Tags: []ec2types.Tag{
{
Key: aws.String("Name"),
Value: aws.String("test-cluster-eip-common"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/cluster/test-cluster"),
Value: aws.String("owned"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/role"),
Value: aws.String("common"),
},
},
},
},
},
})).Return(&ec2.AllocateAddressOutput{
AllocationId: aws.String(eipAllocationID),
}, nil)

ec2Rec.CreateNatGateway(context.TODO(), gomock.Eq(&ec2.CreateNatGatewayInput{
AllocationId: aws.String(eipAllocationID),
SubnetId: aws.String(subnetID),
TagSpecifications: []ec2types.TagSpecification{
{
ResourceType: ec2types.ResourceTypeNatgateway,
Tags: []ec2types.Tag{
{
Key: aws.String("Name"),
Value: aws.String("test-cluster-nat"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/cluster/test-cluster"),
Value: aws.String("owned"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/role"),
Value: aws.String("common"),
})).Return(&ec2.AllocateAddressOutput{
AllocationId: aws.String(eipAllocationID),
}, nil)

ec2Rec.CreateNatGateway(context.TODO(), gomock.Eq(&ec2.CreateNatGatewayInput{
AllocationId: aws.String(eipAllocationID),
SubnetId: aws.String(subnetID),
TagSpecifications: []ec2types.TagSpecification{
{
ResourceType: ec2types.ResourceTypeNatgateway,
Tags: []ec2types.Tag{
{
Key: aws.String("Name"),
Value: aws.String("test-cluster-nat"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/cluster/test-cluster"),
Value: aws.String("owned"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/role"),
Value: aws.String("common"),
},
},
},
},
},
})).Return(&ec2.CreateNatGatewayOutput{
NatGateway: &ec2types.NatGateway{
NatGatewayId: aws.String(natGatewayID),
SubnetId: aws.String(subnetID),
},
}, nil)

ec2Rec.DescribeNatGateways(gomock.Any(), gomock.Eq(&ec2.DescribeNatGatewaysInput{
NatGatewayIds: []string{natGatewayID},
}), gomock.Any()).Return(&ec2.DescribeNatGatewaysOutput{
NatGateways: []ec2types.NatGateway{
{
})).Return(&ec2.CreateNatGatewayOutput{
NatGateway: &ec2types.NatGateway{
NatGatewayId: aws.String(natGatewayID),
SubnetId: aws.String(subnetID),
State: ec2types.NatGatewayStateAvailable,
},
},
}, nil)
}, nil)

ec2Rec.DescribeNatGateways(gomock.Any(), gomock.Eq(&ec2.DescribeNatGatewaysInput{
NatGatewayIds: []string{natGatewayID},
}), gomock.Any()).Return(&ec2.DescribeNatGatewaysOutput{
NatGateways: []ec2types.NatGateway{
{
NatGatewayId: aws.String(natGatewayID),
SubnetId: aws.String(subnetID),
State: ec2types.NatGatewayStateAvailable,
},
},
}, nil)
}
}

routeTableID := fmt.Sprintf("rtb-%d", subnetIndex+1)
Expand Down
18 changes: 18 additions & 0 deletions pkg/cloud/services/network/natgateways.go
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Original file line number Diff line number Diff line change
Expand Up @@ -115,11 +115,29 @@ func (s *Service) updateNatGatewayIPs(updateTags bool) ([]string, error) {
natGatewaysIPs := []string{}
subnetIDs := []string{}

// Find AZs that have private subnets
privateSubnetAZs := make(map[string]bool)
for _, sn := range s.scope.Subnets().FilterPrivate().FilterNonCni() {
if sn.GetResourceID() != "" {
privateSubnetAZs[sn.AvailabilityZone] = true
}
}

// For each AZ with private subnets, find a public subnet and check for NAT gateway
processedAZs := make(map[string]bool)
for _, sn := range s.scope.Subnets().FilterPublic().FilterNonCni() {
if sn.GetResourceID() == "" {
continue
}

// Only process this AZ if it has private subnets and we haven't processed it yet
if !privateSubnetAZs[sn.AvailabilityZone] || processedAZs[sn.AvailabilityZone] {
continue
}

// Mark this AZ as processed
processedAZs[sn.AvailabilityZone] = true

if ngw, ok := existing[sn.GetResourceID()]; ok {
if len(ngw.NatGatewayAddresses) > 0 && ngw.NatGatewayAddresses[0].PublicIp != nil {
natGatewaysIPs = append(natGatewaysIPs, *ngw.NatGatewayAddresses[0].PublicIp)
Expand Down
139 changes: 99 additions & 40 deletions pkg/cloud/services/network/natgateways_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -183,7 +183,7 @@ func TestReconcileNatGateways(t *testing.T) {
},
},
{
name: "two public & 1 private subnet, and one NAT gateway exists",
name: "two public & 1 private subnet, and one NAT gateway exists, should not create additional NAT gateway",
input: []infrav1.SubnetSpec{
{
ID: "subnet-1",
Expand Down Expand Up @@ -224,10 +224,74 @@ func TestReconcileNatGateways(t *testing.T) {
{
NatGatewayId: aws.String("gateway"),
SubnetId: aws.String("subnet-1"),
Tags: []types.Tag{
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/role"),
Value: aws.String("common"),
},
{
Key: aws.String("Name"),
Value: aws.String("test-cluster-nat"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/cluster/test-cluster"),
Value: aws.String("owned"),
},
},
},
},
}, nil)

// Should not create any new NAT gateways because subnet-3 (public subnet in us-east-1b) has no private subnets
m.DescribeAddresses(context.TODO(), gomock.Any()).Times(0)
m.AllocateAddress(context.TODO(), gomock.Any()).Times(0)
m.CreateNatGateway(context.TODO(), gomock.Any()).Times(0)
},
},
{
name: "multiple AZs with private subnets, should create one NAT gateway per AZ",
input: []infrav1.SubnetSpec{
{
ID: "subnet-1",
AvailabilityZone: "us-east-1a",
CidrBlock: "10.0.10.0/24",
IsPublic: true,
},
{
ID: "subnet-2",
AvailabilityZone: "us-east-1a",
CidrBlock: "10.0.12.0/24",
IsPublic: false,
},
{
ID: "subnet-3",
AvailabilityZone: "us-east-1b",
CidrBlock: "10.0.13.0/24",
IsPublic: true,
},
{
ID: "subnet-4",
AvailabilityZone: "us-east-1b",
CidrBlock: "10.0.14.0/24",
IsPublic: false,
},
},
expect: func(m *mocks.MockEC2APIMockRecorder) {
m.DescribeNatGateways(context.TODO(),
gomock.Eq(&ec2.DescribeNatGatewaysInput{
Filter: []types.Filter{
{
Name: aws.String("vpc-id"),
Values: []string{subnetsVPCID},
},
{
Name: aws.String("state"),
Values: []string{"pending", "available"},
},
},
}),
gomock.Any()).Return(&ec2.DescribeNatGatewaysOutput{}, nil)

m.DescribeAddresses(context.TODO(), gomock.Any()).
Return(&ec2.DescribeAddressesOutput{}, nil)

Expand All @@ -254,51 +318,46 @@ func TestReconcileNatGateways(t *testing.T) {
},
}).Return(&ec2.AllocateAddressOutput{
AllocationId: aws.String(ElasticIPAllocationID),
}, nil)
}, nil).Times(2)

m.CreateNatGateway(context.TODO(), &ec2.CreateNatGatewayInput{
AllocationId: aws.String(ElasticIPAllocationID),
SubnetId: aws.String("subnet-3"),
TagSpecifications: []types.TagSpecification{
{
ResourceType: types.ResourceTypeNatgateway,
Tags: []types.Tag{
{
Key: aws.String("Name"),
Value: aws.String("test-cluster-nat"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/cluster/test-cluster"),
Value: aws.String("owned"),
},
{
Key: aws.String("sigs.k8s.io/cluster-api-provider-aws/role"),
Value: aws.String("common"),
},
},
// Should create NAT gateways for both AZs since both have private subnets
m.CreateNatGateway(context.TODO(), gomock.Any()).
Return(&ec2.CreateNatGatewayOutput{
NatGateway: &types.NatGateway{
NatGatewayId: aws.String("natgateway-1"),
SubnetId: aws.String("subnet-1"),
},
},
}).Return(&ec2.CreateNatGatewayOutput{
NatGateway: &types.NatGateway{
NatGatewayId: aws.String("natgateway"),
SubnetId: aws.String("subnet-3"),
},
}, nil)
}, nil)

m.DescribeNatGateways(gomock.Any(), &ec2.DescribeNatGatewaysInput{
NatGatewayIds: []string{"natgateway"},
}, gomock.Any()).Return(&ec2.DescribeNatGatewaysOutput{
NatGateways: []types.NatGateway{
{
State: types.NatGatewayStateAvailable,
NatGatewayId: aws.String("natgateway"),
m.CreateNatGateway(context.TODO(), gomock.Any()).
Return(&ec2.CreateNatGatewayOutput{
NatGateway: &types.NatGateway{
NatGatewayId: aws.String("natgateway-2"),
SubnetId: aws.String("subnet-3"),
},
},
}, nil)
}, nil)

m.DescribeNatGateways(gomock.Any(), gomock.Any(), gomock.Any()).
Return(&ec2.DescribeNatGatewaysOutput{
NatGateways: []types.NatGateway{
{
State: types.NatGatewayStateAvailable,
NatGatewayId: aws.String("natgateway-1"),
SubnetId: aws.String("subnet-1"),
},
},
}, nil)

m.CreateTags(context.TODO(), gomock.AssignableToTypeOf(&ec2.CreateTagsInput{})).
Return(nil, nil).Times(1)
m.DescribeNatGateways(gomock.Any(), gomock.Any(), gomock.Any()).
Return(&ec2.DescribeNatGatewaysOutput{
NatGateways: []types.NatGateway{
{
State: types.NatGatewayStateAvailable,
NatGatewayId: aws.String("natgateway-2"),
SubnetId: aws.String("subnet-3"),
},
},
}, nil)
},
},
{
Expand Down