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Merged
merged 4 commits into from
Aug 4, 2021
Merged

Discovery subnets by available ip addresses #2146

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f190d04
discovery subnet by the count of available ip address
oliviassss Jul 26, 2021
88108ef
update unit test for subnet_resolver
oliviassss Jul 28, 2021
8925c89
filter subnets before iterating subnetsByAZ
oliviassss Jul 30, 2021
857ce64
decouple buildLoadBalancerSubnets from buildLoadBalancerSubnetMappings
oliviassss Aug 4, 2021
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2 changes: 2 additions & 0 deletions pkg/ingress/model_build_load_balancer.go
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Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@ import (

const (
resourceIDLoadBalancer = "LoadBalancer"
minimalAvailableIPAddressCount = int64(8)
)

func (t *defaultModelBuildTask) buildLoadBalancer(ctx context.Context, listenPortConfigByPort map[int64]listenPortConfig) (*elbv2model.LoadBalancer, error) {
Expand Down Expand Up @@ -218,6 +219,7 @@ func (t *defaultModelBuildTask) buildLoadBalancerSubnetMappings(ctx context.Cont
chosenSubnets, err := t.subnetsResolver.ResolveViaDiscovery(ctx,
networking.WithSubnetsResolveLBType(elbv2model.LoadBalancerTypeApplication),
networking.WithSubnetsResolveLBScheme(scheme),
networking.WithSubnetsResolveAvailableIPAddressCount(minimalAvailableIPAddressCount),
)
if err != nil {
return nil, errors.Wrap(err, "couldn't auto-discover subnets")
Expand Down
23 changes: 22 additions & 1 deletion pkg/networking/subnet_resolver.go
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,8 @@ type SubnetsResolveOptions struct {
// The Load Balancer Scheme.
// By default, it's internet-facing.
LBScheme elbv2model.LoadBalancerScheme
// count of available ip addresses
AvailableIPAddressCount int64
}

// ApplyOptions applies slice of SubnetsResolveOption.
Expand Down Expand Up @@ -75,6 +77,13 @@ func WithSubnetsResolveLBScheme(lbScheme elbv2model.LoadBalancerScheme) SubnetsR
}
}

// WithSubnetsResolveAvailableIPAddressCount generates a option that configures AvailableIPAddressCount.
func WithSubnetsResolveAvailableIPAddressCount(AvailableIPAddressCount int64) SubnetsResolveOption {
return func(opts *SubnetsResolveOptions) {
opts.AvailableIPAddressCount = AvailableIPAddressCount
}
}

// SubnetsResolver is responsible for resolve EC2 Subnets for Load Balancers.
type SubnetsResolver interface {
// ResolveViaDiscovery resolve subnets by auto discover matching subnets.
Expand Down Expand Up @@ -143,7 +152,8 @@ func (r *defaultSubnetsResolver) ResolveViaDiscovery(ctx context.Context, opts .
subnets = append(subnets, subnet)
}
}
subnetsByAZ := mapSDKSubnetsByAZ(subnets)
filteredSubnets := r.filterSubnetsByAvailableIPAddress(subnets, resolveOpts.AvailableIPAddressCount)
subnetsByAZ := mapSDKSubnetsByAZ(filteredSubnets)
chosenSubnets := make([]*ec2sdk.Subnet, 0, len(subnetsByAZ))
for az, subnets := range subnetsByAZ {
if len(subnets) == 1 {
Expand Down Expand Up @@ -370,3 +380,14 @@ func sortSubnetsByID(subnets []*ec2sdk.Subnet) {
return awssdk.StringValue(subnets[i].SubnetId) < awssdk.StringValue(subnets[j].SubnetId)
})
}

func (r *defaultSubnetsResolver) filterSubnetsByAvailableIPAddress(subnets []*ec2sdk.Subnet, availableIPAddressCount int64) []*ec2sdk.Subnet {
filteredSubnets := make([]*ec2sdk.Subnet, 0, len(subnets))
for _, subnet := range subnets {
if awssdk.Int64Value(subnet.AvailableIpAddressCount) >= availableIPAddressCount {
filteredSubnets = append(filteredSubnets, subnet)
}
}
r.logger.V(4).Info("Subnets filtered by Available IP Address: ", filteredSubnets)
return filteredSubnets
}
106 changes: 106 additions & 0 deletions pkg/networking/subnet_resolver_test.go
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Expand Up @@ -35,6 +35,9 @@ func Test_defaultSubnetsResolver_ResolveViaDiscovery(t *testing.T) {
type args struct {
opts []SubnetsResolveOption
}
const (
minimalAvailableIPAddressCount = int64(8)
)
tests := []struct {
name string
fields fields
Expand Down Expand Up @@ -886,6 +889,109 @@ func Test_defaultSubnetsResolver_ResolveViaDiscovery(t *testing.T) {
},
},
},
{
name: "subnets with insufficient available ip addresses get ignored",
fields: fields{
vpcID: "vpc-1",
clusterName: "kube-cluster",
describeSubnetsAsListCalls: []describeSubnetsAsListCall{
{
input: &ec2sdk.DescribeSubnetsInput{
Filters: []*ec2sdk.Filter{
{
Name: awssdk.String("tag:kubernetes.io/role/elb"),
Values: awssdk.StringSlice([]string{"", "1"}),
},
{
Name: awssdk.String("vpc-id"),
Values: awssdk.StringSlice([]string{"vpc-1"}),
},
},
},
output: []*ec2sdk.Subnet{
{
SubnetId: awssdk.String("subnet-1"),
AvailabilityZone: awssdk.String("us-west-2a"),
AvailabilityZoneId: awssdk.String("usw2-az1"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(0),
},
{
SubnetId: awssdk.String("subnet-3"),
AvailabilityZone: awssdk.String("us-west-2a"),
AvailabilityZoneId: awssdk.String("usw2-az1"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(8),
},
{
SubnetId: awssdk.String("subnet-4"),
AvailabilityZone: awssdk.String("us-west-2b"),
AvailabilityZoneId: awssdk.String("usw2-az2"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(25),
},
{
SubnetId: awssdk.String("subnet-2"),
AvailabilityZone: awssdk.String("us-west-2a"),
AvailabilityZoneId: awssdk.String("usw2-az1"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(2),
},
{
SubnetId: awssdk.String("subnet-5"),
AvailabilityZone: awssdk.String("us-west-2b"),
AvailabilityZoneId: awssdk.String("usw2-az2"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(10),
},
},
},
},
fetchAZInfosCalls: []fetchAZInfosCall{
{
availabilityZoneIDs: []string{"usw2-az1"},
azInfoByAZID: map[string]ec2sdk.AvailabilityZone{
"usw2-az1": {
ZoneId: awssdk.String("usw2-az1"),
ZoneType: awssdk.String("availability-zone"),
},
},
},
{
availabilityZoneIDs: []string{"usw2-az2"},
azInfoByAZID: map[string]ec2sdk.AvailabilityZone{
"usw2-az2": {
ZoneId: awssdk.String("usw2-az2"),
ZoneType: awssdk.String("availability-zone"),
},
},
},
},
},
args: args{
opts: []SubnetsResolveOption{
WithSubnetsResolveLBType(elbv2model.LoadBalancerTypeNetwork),
WithSubnetsResolveLBScheme(elbv2model.LoadBalancerSchemeInternetFacing),
WithSubnetsResolveAvailableIPAddressCount(minimalAvailableIPAddressCount),
},
},
want: []*ec2sdk.Subnet{
{
SubnetId: awssdk.String("subnet-3"),
AvailabilityZone: awssdk.String("us-west-2a"),
AvailabilityZoneId: awssdk.String("usw2-az1"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(8),
},
{
SubnetId: awssdk.String("subnet-4"),
AvailabilityZone: awssdk.String("us-west-2b"),
AvailabilityZoneId: awssdk.String("usw2-az2"),
VpcId: awssdk.String("vpc-1"),
AvailableIpAddressCount: awssdk.Int64(25),
},
},
},
}

for _, tt := range tests {
Expand Down
13 changes: 13 additions & 0 deletions pkg/service/model_build_load_balancer.go
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Expand Up @@ -27,6 +27,7 @@ const (
lbAttrsAccessLogsS3Prefix = "access_logs.s3.prefix"
lbAttrsLoadBalancingCrossZoneEnabled = "load_balancing.cross_zone.enabled"
resourceIDLoadBalancer = "LoadBalancer"
minimalAvailableIPAddressCount = int64(8)
)

func (t *defaultModelBuildTask) buildLoadBalancer(ctx context.Context, scheme elbv2model.LoadBalancerScheme) error {
Expand Down Expand Up @@ -267,6 +268,18 @@ func (t *defaultModelBuildTask) buildLoadBalancerSubnets(ctx context.Context, sc
)
}

// for internet-facing Load Balancers, the subnets mush have at least 8 available IP addresses;
// for internal Load Balancers, this is only required if private ip address is not assigned
var privateIpv4Addresses []string
ipv4Configured := t.annotationParser.ParseStringSliceAnnotation(annotations.SvcLBSuffixPrivateIpv4Addresses, &privateIpv4Addresses, t.service.Annotations)
if (scheme == elbv2model.LoadBalancerSchemeInternetFacing) ||
((scheme == elbv2model.LoadBalancerSchemeInternal) && !ipv4Configured) {
return t.subnetsResolver.ResolveViaDiscovery(ctx,
networking.WithSubnetsResolveLBType(elbv2model.LoadBalancerTypeNetwork),
networking.WithSubnetsResolveLBScheme(scheme),
networking.WithSubnetsResolveAvailableIPAddressCount(minimalAvailableIPAddressCount),
)
}
return t.subnetsResolver.ResolveViaDiscovery(ctx,
networking.WithSubnetsResolveLBType(elbv2model.LoadBalancerTypeNetwork),
networking.WithSubnetsResolveLBScheme(scheme),
Expand Down