chore: dynamic cluster CIDR resolution

pkg/controllers/nodeclass/controller.go

@@ -87,6 +87,9 @@ func (c *Controller) Reconcile(ctx context.Context, nodeClass *v1beta1.EC2NodeCl
 		c.resolveAMIs(ctx, nodeClass),
 		c.resolveInstanceProfile(ctx, nodeClass),
 	)
+	if lo.FromPtr(nodeClass.Spec.AMIFamily) == v1beta1.AMIFamilyAL2023 {
+		err = multierr.Append(err, c.launchTemplateProvider.ResolveClusterCIDR(ctx))
+	}
 	if !equality.Semantic.DeepEqual(stored, nodeClass) {
 		statusCopy := nodeClass.DeepCopy()
 		if patchErr := c.kubeClient.Patch(ctx, nodeClass, client.MergeFrom(stored)); err != nil {

pkg/fake/eksapi.go

@@ -20,6 +20,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/request"
 	"github.com/aws/aws-sdk-go/service/eks"
 	"github.com/aws/aws-sdk-go/service/eks/eksiface"
+	"github.com/samber/lo"
 )
 
 const ()
@@ -35,6 +36,10 @@ type EKSAPI struct {
 	EKSAPIBehavior
 }
 
+func NewEKSAPI() *EKSAPI {
+	return &EKSAPI{}
+}
+
 // Reset must be called between tests otherwise tests will pollute
 // each other.
 func (s *EKSAPI) Reset() {
@@ -43,6 +48,12 @@ func (s *EKSAPI) Reset() {
 
 func (s *EKSAPI) DescribeClusterWithContext(_ context.Context, input *eks.DescribeClusterInput, _ ...request.Option) (*eks.DescribeClusterOutput, error) {
 	return s.DescribeClusterBehavior.Invoke(input, func(*eks.DescribeClusterInput) (*eks.DescribeClusterOutput, error) {
-		return nil, nil
+		return &eks.DescribeClusterOutput{
+			Cluster: &eks.Cluster{
+				KubernetesNetworkConfig: &eks.KubernetesNetworkConfigResponse{
+					ServiceIpv4Cidr: lo.ToPtr("10.100.0.0/16"),
+				},
+			},
+		}, nil
 	})
 }

pkg/operator/operator.go

@@ -122,12 +122,6 @@ func NewOperator(ctx context.Context, operator *operator.Operator) (context.Cont
 	} else {
 		logging.FromContext(ctx).With("cluster-endpoint", clusterEndpoint).Debugf("discovered cluster endpoint")
 	}
-	clusterCIDR, err := ResolveClusterCIDR(ctx, eks.New(sess))
-	if err != nil {
-		logging.FromContext(ctx).Fatalf("unable to detect the cluster CIDR, %s", err)
-	} else {
-		logging.FromContext(ctx).With("cluster-cidr", clusterCIDR).Debugf("discovered cluster CIDR")
-	}
 	// We perform best-effort on resolving the kube-dns IP
 	kubeDNSIP, err := kubeDNSIP(ctx, operator.KubernetesInterface)
 	if err != nil {
@@ -155,6 +149,7 @@ func NewOperator(ctx context.Context, operator *operator.Operator) (context.Cont
 		ctx,
 		cache.New(awscache.DefaultTTL, awscache.DefaultCleanupInterval),
 		ec2api,
+		eks.New(sess),
 		amiResolver,
 		securityGroupProvider,
 		subnetProvider,
@@ -163,7 +158,6 @@ func NewOperator(ctx context.Context, operator *operator.Operator) (context.Cont
 		operator.Elected(),
 		kubeDNSIP,
 		clusterEndpoint,
-		clusterCIDR,
 	)
 	instanceTypeProvider := instancetype.NewProvider(
 		*sess.Config.Region,
@@ -241,23 +235,6 @@ func ResolveClusterEndpoint(ctx context.Context, eksAPI eksiface.EKSAPI) (string
 	return *out.Cluster.Endpoint, nil
 }
 
-func ResolveClusterCIDR(ctx context.Context, eksAPI eksiface.EKSAPI) (string, error) {
-	out, err := eksAPI.DescribeClusterWithContext(ctx, &eks.DescribeClusterInput{
-		Name: aws.String(options.FromContext(ctx).ClusterName),
-	})
-	if err != nil {
-		return "", fmt.Errorf("failed to resolve cluster CIDR, %w", err)
-	}
-
-	if ipv4CIDR := out.Cluster.KubernetesNetworkConfig.ServiceIpv4Cidr; ipv4CIDR != nil {
-		return *ipv4CIDR, nil
-	}
-	if ipv6CIDR := out.Cluster.KubernetesNetworkConfig.ServiceIpv6Cidr; ipv6CIDR != nil {
-		return *ipv6CIDR, nil
-	}
-	return "", fmt.Errorf("failed to resolve cluster CIDR")
-}
-
 func getCABundle(ctx context.Context, restConfig *rest.Config) (*string, error) {
 	// Discover CA Bundle from the REST client. We could alternatively
 	// have used the simpler client-go InClusterConfig() method.

pkg/providers/amifamily/bootstrap/bootstrap.go

@@ -34,7 +34,7 @@ import (
 type Options struct {
 	ClusterName             string
 	ClusterEndpoint         string
-	ClusterCIDR             string
+	ClusterCIDR             *string
 	KubeletConfig           *corev1beta1.KubeletConfiguration
 	Taints                  []core.Taint      `hash:"set"`
 	Labels                  map[string]string `hash:"set"`

pkg/providers/amifamily/bootstrap/nodeadm.go

@@ -65,7 +65,7 @@ func (n Nodeadm) getNodeConfigYAML() (string, error) {
 			Cluster: admv1alpha1.ClusterDetails{
 				Name:              n.ClusterName,
 				APIServerEndpoint: n.ClusterEndpoint,
-				CIDR:              n.ClusterCIDR,
+				CIDR:              lo.FromPtr(n.ClusterCIDR),
 			},
 		},
 	}

pkg/providers/amifamily/resolver.go

@@ -50,7 +50,7 @@ type Resolver struct {
 type Options struct {
 	ClusterName         string
 	ClusterEndpoint     string
-	ClusterCIDR         string
+	ClusterCIDR         *string
 	InstanceProfile     string
 	CABundle            *string `hash:"ignore"`
 	InstanceStorePolicy *v1beta1.InstanceStorePolicy

pkg/providers/launchtemplate/launchtemplate.go

@@ -29,6 +29,8 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/ec2"
 	"github.com/aws/aws-sdk-go/service/ec2/ec2iface"
+	"github.com/aws/aws-sdk-go/service/eks"
+	"github.com/aws/aws-sdk-go/service/eks/eksiface"
 	"github.com/mitchellh/hashstructure/v2"
 	"github.com/patrickmn/go-cache"
 	"github.com/samber/lo"
@@ -64,6 +66,7 @@ type LaunchTemplate struct {
 type Provider struct {
 	sync.Mutex
 	ec2api                  ec2iface.EC2API
+	eksapi                  eksiface.EKSAPI
 	amiFamily               *amifamily.Resolver
 	securityGroupProvider   *securitygroup.Provider
 	subnetProvider          *subnet.Provider
@@ -73,14 +76,15 @@ type Provider struct {
 	KubeDNSIP               net.IP
 	CABundle                *string
 	ClusterEndpoint         string
-	ClusterCIDR             string
+	ClusterCIDR             *string
 }
 
-func NewProvider(ctx context.Context, cache *cache.Cache, ec2api ec2iface.EC2API, amiFamily *amifamily.Resolver,
+func NewProvider(ctx context.Context, cache *cache.Cache, ec2api ec2iface.EC2API, eksapi eksiface.EKSAPI, amiFamily *amifamily.Resolver,
 	securityGroupProvider *securitygroup.Provider, subnetProvider *subnet.Provider, instanceProfileProvider *instanceprofile.Provider,
-	caBundle *string, startAsync <-chan struct{}, kubeDNSIP net.IP, clusterEndpoint string, clusterCIDR string) *Provider {
+	caBundle *string, startAsync <-chan struct{}, kubeDNSIP net.IP, clusterEndpoint string) *Provider {
 	l := &Provider{
 		ec2api:                  ec2api,
+		eksapi:                  eksapi,
 		amiFamily:               amiFamily,
 		securityGroupProvider:   securityGroupProvider,
 		subnetProvider:          subnetProvider,
@@ -90,7 +94,6 @@ func NewProvider(ctx context.Context, cache *cache.Cache, ec2api ec2iface.EC2API
 		cm:                      pretty.NewChangeMonitor(),
 		KubeDNSIP:               kubeDNSIP,
 		ClusterEndpoint:         clusterEndpoint,
-		ClusterCIDR:             clusterCIDR,
 	}
 	l.cache.OnEvicted(l.cachedEvictedFunc(ctx))
 	go func() {
@@ -427,3 +430,24 @@ func (p *Provider) DeleteLaunchTemplates(ctx context.Context, nodeClass *v1beta1
 	}
 	return nil
 }
+
+func (p *Provider) ResolveClusterCIDR(ctx context.Context) error {
+	if p.ClusterCIDR != nil {
+		return nil
+	}
+	out, err := p.eksapi.DescribeClusterWithContext(ctx, &eks.DescribeClusterInput{
+		Name: aws.String(options.FromContext(ctx).ClusterName),
+	})
+	if err != nil {
+		return fmt.Errorf("failed to resolve cluster CIDR, %w", err)
+	}
+	if ipv4CIDR := out.Cluster.KubernetesNetworkConfig.ServiceIpv4Cidr; ipv4CIDR != nil {
+		p.ClusterCIDR = ipv4CIDR
+		return nil
+	}
+	if ipv6CIDR := out.Cluster.KubernetesNetworkConfig.ServiceIpv6Cidr; ipv6CIDR != nil {
+		p.ClusterCIDR = ipv6CIDR
+		return nil
+	}
+	return fmt.Errorf("failed to resolve cluster CIDR")
+}

pkg/test/environment.go

@@ -82,6 +82,7 @@ type Environment struct {
 func NewEnvironment(ctx context.Context, env *coretest.Environment) *Environment {
 	// API
 	ec2api := fake.NewEC2API()
+	eksapi := fake.NewEKSAPI()
 	ssmapi := fake.NewSSMAPI()
 	iamapi := fake.NewIAMAPI()
 
@@ -110,6 +111,7 @@ func NewEnvironment(ctx context.Context, env *coretest.Environment) *Environment
 			ctx,
 			launchTemplateCache,
 			ec2api,
+			eksapi,
 			amiResolver,
 			securityGroupProvider,
 			subnetProvider,
@@ -118,7 +120,6 @@ func NewEnvironment(ctx context.Context, env *coretest.Environment) *Environment
 			make(chan struct{}),
 			net.ParseIP("10.0.100.10"),
 			"https://test-cluster",
-			"10.100.0.0/16",
 		)
 	instanceProvider :=
 		instance.NewProvider(ctx,