kops/pkg/model/awsmodel/api_loadbalancer.go

492 lines
14 KiB
Go

/*
Copyright 2019 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package awsmodel
import (
"fmt"
"sort"
"time"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/klog/v2"
"k8s.io/kops/pkg/apis/kops"
"k8s.io/kops/pkg/dns"
"k8s.io/kops/upup/pkg/fi"
"k8s.io/kops/upup/pkg/fi/cloudup/awstasks"
)
// LoadBalancerDefaultIdleTimeout is the default idle time for the ELB
const LoadBalancerDefaultIdleTimeout = 5 * time.Minute
// APILoadBalancerBuilder builds a LoadBalancer for accessing the API
type APILoadBalancerBuilder struct {
*AWSModelContext
Lifecycle *fi.Lifecycle
SecurityLifecycle *fi.Lifecycle
}
var _ fi.ModelBuilder = &APILoadBalancerBuilder{}
// Build is responsible for building the KubeAPI tasks for the aws model
func (b *APILoadBalancerBuilder) Build(c *fi.ModelBuilderContext) error {
// Configuration where an ELB fronts the API
if !b.UseLoadBalancerForAPI() {
return nil
}
lbSpec := b.Cluster.Spec.API.LoadBalancer
if lbSpec == nil {
// Skipping API ELB creation; not requested in Spec
return nil
}
switch lbSpec.Type {
case kops.LoadBalancerTypeInternal, kops.LoadBalancerTypePublic:
// OK
default:
return fmt.Errorf("unhandled LoadBalancer type %q", lbSpec.Type)
}
// Compute the subnets - only one per zone, and then break ties based on chooseBestSubnetForELB
var elbSubnets []*awstasks.Subnet
{
subnetsByZone := make(map[string][]*kops.ClusterSubnetSpec)
for i := range b.Cluster.Spec.Subnets {
subnet := &b.Cluster.Spec.Subnets[i]
switch subnet.Type {
case kops.SubnetTypePublic, kops.SubnetTypeUtility:
if lbSpec.Type != kops.LoadBalancerTypePublic {
continue
}
case kops.SubnetTypePrivate:
if lbSpec.Type != kops.LoadBalancerTypeInternal {
continue
}
default:
return fmt.Errorf("subnet %q had unknown type %q", subnet.Name, subnet.Type)
}
subnetsByZone[subnet.Zone] = append(subnetsByZone[subnet.Zone], subnet)
}
for zone, subnets := range subnetsByZone {
subnet := b.chooseBestSubnetForELB(zone, subnets)
elbSubnets = append(elbSubnets, b.LinkToSubnet(subnet))
}
}
var clb *awstasks.ClassicLoadBalancer
var nlb *awstasks.NetworkLoadBalancer
{
loadBalancerName := b.LBName32("api")
idleTimeout := LoadBalancerDefaultIdleTimeout
if lbSpec.IdleTimeoutSeconds != nil {
idleTimeout = time.Second * time.Duration(*lbSpec.IdleTimeoutSeconds)
}
listeners := map[string]*awstasks.ClassicLoadBalancerListener{
"443": {InstancePort: 443},
}
nlbListeners := []*awstasks.NetworkLoadBalancerListener{
{
Port: 443,
TargetGroupName: b.NLBTargetGroupName("tcp"),
},
}
if lbSpec.SSLCertificate != "" {
listeners["443"].SSLCertificateID = lbSpec.SSLCertificate
nlbListeners[0].Port = 8443
nlbListener := &awstasks.NetworkLoadBalancerListener{
Port: 443,
TargetGroupName: b.NLBTargetGroupName("tls"),
SSLCertificateID: lbSpec.SSLCertificate,
}
if lbSpec.SSLPolicy != nil {
nlbListener.SSLPolicy = *lbSpec.SSLPolicy
}
nlbListeners = append(nlbListeners, nlbListener)
}
if lbSpec.SecurityGroupOverride != nil {
klog.V(1).Infof("WARNING: You are overwriting the Load Balancers, Security Group. When this is done you are responsible for ensure the correct rules!")
}
tags := b.CloudTags(loadBalancerName, false)
for k, v := range b.Cluster.Spec.CloudLabels {
tags[k] = v
}
// Override the returned name to be the expected ELB name
tags["Name"] = "api." + b.ClusterName()
name := b.NLBName("api")
nlb = &awstasks.NetworkLoadBalancer{
Name: &name,
Lifecycle: b.Lifecycle,
LoadBalancerName: fi.String(loadBalancerName),
Subnets: elbSubnets,
Listeners: nlbListeners,
TargetGroups: make([]*awstasks.TargetGroup, 0),
Tags: tags,
VPC: b.LinkToVPC(),
Type: fi.String("network"),
}
clb = &awstasks.ClassicLoadBalancer{
Name: fi.String("api." + b.ClusterName()),
Lifecycle: b.Lifecycle,
LoadBalancerName: fi.String(loadBalancerName),
SecurityGroups: []*awstasks.SecurityGroup{
b.LinkToELBSecurityGroup("api"),
},
Subnets: elbSubnets,
Listeners: listeners,
// Configure fast-recovery health-checks
HealthCheck: &awstasks.ClassicLoadBalancerHealthCheck{
Target: fi.String("SSL:443"),
Timeout: fi.Int64(5),
Interval: fi.Int64(10),
HealthyThreshold: fi.Int64(2),
UnhealthyThreshold: fi.Int64(2),
},
ConnectionSettings: &awstasks.ClassicLoadBalancerConnectionSettings{
IdleTimeout: fi.Int64(int64(idleTimeout.Seconds())),
},
Tags: tags,
}
if lbSpec.CrossZoneLoadBalancing == nil {
lbSpec.CrossZoneLoadBalancing = fi.Bool(false)
}
clb.CrossZoneLoadBalancing = &awstasks.ClassicLoadBalancerCrossZoneLoadBalancing{
Enabled: lbSpec.CrossZoneLoadBalancing,
}
nlb.CrossZoneLoadBalancing = lbSpec.CrossZoneLoadBalancing
switch lbSpec.Type {
case kops.LoadBalancerTypeInternal:
clb.Scheme = fi.String("internal")
nlb.Scheme = fi.String("internal")
case kops.LoadBalancerTypePublic:
clb.Scheme = nil
nlb.Scheme = nil
default:
return fmt.Errorf("unknown load balancer Type: %q", lbSpec.Type)
}
if b.APILoadBalancerClass() == kops.LoadBalancerClassClassic {
c.AddTask(clb)
} else if b.APILoadBalancerClass() == kops.LoadBalancerClassNetwork {
tcpGroupName := b.NLBTargetGroupName("tcp")
tcpGroupTags := b.CloudTags(tcpGroupName, false)
// Override the returned name to be the expected NLB TG name
tcpGroupTags["Name"] = tcpGroupName
tg := &awstasks.TargetGroup{
Name: fi.String(tcpGroupName),
VPC: b.LinkToVPC(),
Tags: tcpGroupTags,
Protocol: fi.String("TCP"),
Port: fi.Int64(443),
HealthyThreshold: fi.Int64(2),
UnhealthyThreshold: fi.Int64(2),
Shared: fi.Bool(false),
}
c.AddTask(tg)
nlb.TargetGroups = append(nlb.TargetGroups, tg)
if lbSpec.SSLCertificate != "" {
tlsGroupName := b.NLBTargetGroupName("tls")
tlsGroupTags := b.CloudTags(tlsGroupName, false)
// Override the returned name to be the expected NLB TG name
tlsGroupTags["Name"] = tlsGroupName
secondaryTG := &awstasks.TargetGroup{
Name: fi.String(tlsGroupName),
VPC: b.LinkToVPC(),
Tags: tlsGroupTags,
Protocol: fi.String("TLS"),
Port: fi.Int64(443),
HealthyThreshold: fi.Int64(2),
UnhealthyThreshold: fi.Int64(2),
Shared: fi.Bool(false),
}
c.AddTask(secondaryTG)
nlb.TargetGroups = append(nlb.TargetGroups, secondaryTG)
}
sort.Stable(awstasks.OrderTargetGroupsByName(nlb.TargetGroups))
c.AddTask(nlb)
}
}
var lbSG *awstasks.SecurityGroup
{
lbSG = &awstasks.SecurityGroup{
Name: fi.String(b.ELBSecurityGroupName("api")),
Lifecycle: b.SecurityLifecycle,
Description: fi.String("Security group for api ELB"),
RemoveExtraRules: []string{"port=443"},
VPC: b.LinkToVPC(),
}
lbSG.Tags = b.CloudTags(*lbSG.Name, false)
if lbSpec.SecurityGroupOverride != nil {
lbSG.ID = fi.String(*lbSpec.SecurityGroupOverride)
lbSG.Shared = fi.Bool(true)
}
c.AddTask(lbSG)
}
// Allow traffic from ELB to egress freely
if b.APILoadBalancerClass() == kops.LoadBalancerClassClassic {
t := &awstasks.SecurityGroupRule{
Name: fi.String("api-elb-egress"),
Lifecycle: b.SecurityLifecycle,
CIDR: fi.String("0.0.0.0/0"),
Egress: fi.Bool(true),
SecurityGroup: lbSG,
}
c.AddTask(t)
}
// Allow traffic into the ELB from KubernetesAPIAccess CIDRs
if b.APILoadBalancerClass() == kops.LoadBalancerClassClassic {
for _, cidr := range b.Cluster.Spec.KubernetesAPIAccess {
t := &awstasks.SecurityGroupRule{
Name: fi.String("https-api-elb-" + cidr),
Lifecycle: b.SecurityLifecycle,
CIDR: fi.String(cidr),
FromPort: fi.Int64(443),
Protocol: fi.String("tcp"),
SecurityGroup: lbSG,
ToPort: fi.Int64(443),
}
c.AddTask(t)
// Allow ICMP traffic required for PMTU discovery
c.AddTask(&awstasks.SecurityGroupRule{
Name: fi.String("icmp-pmtu-api-elb-" + cidr),
Lifecycle: b.SecurityLifecycle,
CIDR: fi.String(cidr),
FromPort: fi.Int64(3),
Protocol: fi.String("icmp"),
SecurityGroup: lbSG,
ToPort: fi.Int64(4),
})
}
}
masterGroups, err := b.GetSecurityGroups(kops.InstanceGroupRoleMaster)
if err != nil {
return err
}
if b.APILoadBalancerClass() == kops.LoadBalancerClassNetwork {
for _, cidr := range b.Cluster.Spec.KubernetesAPIAccess {
for _, masterGroup := range masterGroups {
t := &awstasks.SecurityGroupRule{
Name: fi.String(fmt.Sprintf("https-api-elb-%s", cidr)),
Lifecycle: b.SecurityLifecycle,
CIDR: fi.String(cidr),
FromPort: fi.Int64(443),
Protocol: fi.String("tcp"),
SecurityGroup: masterGroup.Task,
ToPort: fi.Int64(443),
}
c.AddTask(t)
// Allow ICMP traffic required for PMTU discovery
c.AddTask(&awstasks.SecurityGroupRule{
Name: fi.String("icmp-pmtu-api-elb-" + cidr),
Lifecycle: b.SecurityLifecycle,
CIDR: fi.String(cidr),
FromPort: fi.Int64(3),
Protocol: fi.String("icmp"),
SecurityGroup: masterGroup.Task,
ToPort: fi.Int64(4),
})
if b.Cluster.Spec.API != nil && b.Cluster.Spec.API.LoadBalancer != nil && b.Cluster.Spec.API.LoadBalancer.SSLCertificate != "" {
// Allow access to masters on secondary port through NLB
c.AddTask(&awstasks.SecurityGroupRule{
Name: fi.String(fmt.Sprintf("tcp-api-%s", cidr)),
Lifecycle: b.SecurityLifecycle,
CIDR: fi.String(cidr),
FromPort: fi.Int64(8443),
Protocol: fi.String("tcp"),
SecurityGroup: masterGroup.Task,
ToPort: fi.Int64(8443),
})
}
}
}
}
// Add precreated additional security groups to the ELB
if b.APILoadBalancerClass() == kops.LoadBalancerClassClassic {
for _, id := range b.Cluster.Spec.API.LoadBalancer.AdditionalSecurityGroups {
t := &awstasks.SecurityGroup{
Name: fi.String(id),
Lifecycle: b.SecurityLifecycle,
ID: fi.String(id),
Shared: fi.Bool(true),
}
if err := c.EnsureTask(t); err != nil {
return err
}
clb.SecurityGroups = append(clb.SecurityGroups, t)
}
}
// Allow HTTPS to the master instances from the ELB
if b.APILoadBalancerClass() == kops.LoadBalancerClassClassic {
for _, masterGroup := range masterGroups {
suffix := masterGroup.Suffix
c.AddTask(&awstasks.SecurityGroupRule{
Name: fi.String(fmt.Sprintf("https-elb-to-master%s", suffix)),
Lifecycle: b.SecurityLifecycle,
FromPort: fi.Int64(443),
Protocol: fi.String("tcp"),
SecurityGroup: masterGroup.Task,
SourceGroup: lbSG,
ToPort: fi.Int64(443),
})
}
} else if b.APILoadBalancerClass() == kops.LoadBalancerClassNetwork {
for _, masterGroup := range masterGroups {
suffix := masterGroup.Suffix
c.AddTask(&awstasks.SecurityGroupRule{
Name: fi.String(fmt.Sprintf("https-elb-to-master%s", suffix)),
Lifecycle: b.SecurityLifecycle,
FromPort: fi.Int64(443),
Protocol: fi.String("tcp"),
SecurityGroup: masterGroup.Task,
ToPort: fi.Int64(443),
CIDR: fi.String(b.Cluster.Spec.NetworkCIDR),
})
for _, cidr := range b.Cluster.Spec.AdditionalNetworkCIDRs {
c.AddTask(&awstasks.SecurityGroupRule{
Name: fi.String(fmt.Sprintf("https-lb-to-master%s-%s", suffix, cidr)),
Lifecycle: b.SecurityLifecycle,
FromPort: fi.Int64(443),
Protocol: fi.String("tcp"),
SecurityGroup: masterGroup.Task,
ToPort: fi.Int64(443),
CIDR: fi.String(cidr),
})
}
}
}
if dns.IsGossipHostname(b.Cluster.Name) || b.UsePrivateDNS() {
// Ensure the LB hostname is included in the TLS certificate,
// if we're not going to use an alias for it
clb.ForAPIServer = true
nlb.ForAPIServer = true
}
return nil
}
type scoredSubnet struct {
score int
subnet *kops.ClusterSubnetSpec
}
type ByScoreDescending []*scoredSubnet
func (a ByScoreDescending) Len() int { return len(a) }
func (a ByScoreDescending) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByScoreDescending) Less(i, j int) bool {
if a[i].score != a[j].score {
// ! to sort highest score first
return !(a[i].score < a[j].score)
}
// Use name to break ties consistently
return a[i].subnet.Name < a[j].subnet.Name
}
// Choose between subnets in a zone.
// We have already applied the rules to match internal subnets to internal ELBs and vice-versa for public-facing ELBs.
// For internal ELBs: we prefer the master subnets
// For public facing ELBs: we prefer the utility subnets
func (b *APILoadBalancerBuilder) chooseBestSubnetForELB(zone string, subnets []*kops.ClusterSubnetSpec) *kops.ClusterSubnetSpec {
if len(subnets) == 0 {
return nil
}
if len(subnets) == 1 {
return subnets[0]
}
migSubnets := sets.NewString()
for _, ig := range b.MasterInstanceGroups() {
for _, subnet := range ig.Spec.Subnets {
migSubnets.Insert(subnet)
}
}
var scoredSubnets []*scoredSubnet
for _, subnet := range subnets {
score := 0
if migSubnets.Has(subnet.Name) {
score += 1
}
if subnet.Type == kops.SubnetTypeUtility {
score += 1
}
scoredSubnets = append(scoredSubnets, &scoredSubnet{
score: score,
subnet: subnet,
})
}
sort.Sort(ByScoreDescending(scoredSubnets))
if scoredSubnets[0].score == scoredSubnets[1].score {
klog.V(2).Infof("Making arbitrary choice between subnets in zone %q to attach to ELB (%q vs %q)", zone, scoredSubnets[0].subnet.Name, scoredSubnets[1].subnet.Name)
}
return scoredSubnets[0].subnet
}