Fix CoreDNS scheduling on Fargate failing when component label in selector (#8357)

Update cluster creation with Fargate to support adding a CoreDNS profile with the selector label `eks.amazonaws.com/component: coredns`.
Closes issue #8355

Author: naclonts

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/aws/aws-sdk-go-v2 v1.36.3
 	github.com/aws/aws-sdk-go-v2/config v1.29.12
 	github.com/aws/aws-sdk-go-v2/credentials v1.17.65
-	github.com/aws/aws-sdk-go-v2/service/autoscaling v1.52.3
+	github.com/aws/aws-sdk-go-v2/service/autoscaling v1.52.4
 	github.com/aws/aws-sdk-go-v2/service/cloudformation v1.59.2
 	github.com/aws/aws-sdk-go-v2/service/cloudtrail v1.48.4
 	github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs v1.47.3

go.sum

@@ -124,8 +124,8 @@ github.com/aws/aws-sdk-go-v2/internal/ini v1.8.3 h1:bIqFDwgGXXN1Kpp99pDOdKMTTb5d
 github.com/aws/aws-sdk-go-v2/internal/ini v1.8.3/go.mod h1:H5O/EsxDWyU+LP/V8i5sm8cxoZgc2fdNR9bxlOFrQTo=
 github.com/aws/aws-sdk-go-v2/internal/v4a v1.3.33 h1:/frG8aV09yhCVSOEC2pzktflJJO48NwY3xntHBwxHiA=
 github.com/aws/aws-sdk-go-v2/internal/v4a v1.3.33/go.mod h1:8vwASlAcV366M+qxZnjNzCjeastk1Rt1bpSRaGZanGU=
-github.com/aws/aws-sdk-go-v2/service/autoscaling v1.52.3 h1:QsKdBxtC8csnKt5BbV7D1op4Nf13p2YkTJIkppaCakw=
-github.com/aws/aws-sdk-go-v2/service/autoscaling v1.52.3/go.mod h1:CDqMoc3KRdZJ8qziW96J35lKH01Wq3B2aihtHj2JbRs=
+github.com/aws/aws-sdk-go-v2/service/autoscaling v1.52.4 h1:vzLD0FyNU4uxf2QE5UDG0jSEitiJXbVEUwf2Sk3usF4=
+github.com/aws/aws-sdk-go-v2/service/autoscaling v1.52.4/go.mod h1:CDqMoc3KRdZJ8qziW96J35lKH01Wq3B2aihtHj2JbRs=
 github.com/aws/aws-sdk-go-v2/service/cloudformation v1.59.2 h1:o9cuZdZlI9VWMqsNa2mnf2IRsFAROHnaYA1BW3lHGuY=
 github.com/aws/aws-sdk-go-v2/service/cloudformation v1.59.2/go.mod h1:penaZKzGmqHGZId4EUCBIW/f9l4Y7hQ5NKd45yoCYuI=
 github.com/aws/aws-sdk-go-v2/service/cloudtrail v1.48.4 h1:pQpinmWv9jEisDR6/DccOf2cXdAf/CAwQ39nfJfJDlE=

pkg/fargate/coredns/coredns.go

@@ -43,7 +43,7 @@ func IsSchedulableOnFargate(profiles []*api.FargateProfile) bool {
 }
 
 func selectsCoreDNS(selector api.FargateProfileSelector) bool {
-	return selector.Namespace == Namespace && len(selector.Labels) == 0
+	return selector.Namespace == Namespace && (len(selector.Labels) == 0 || selector.Labels["eks.amazonaws.com/component"] == Name)
 }
 
 // IsScheduledOnFargate checks if EKS' coredns is scheduled onto Fargate.

pkg/fargate/coredns/coredns_test.go

@@ -73,6 +73,20 @@ var (
 		},
 	}
 
+	profileSelectingCoreDNSWithComponentLabel = []*api.FargateProfile{
+		{
+			Name: "selecting-coredns-with-label",
+			Selectors: []api.FargateProfileSelector{
+				{
+					Namespace: "kube-system",
+					Labels: map[string]string{
+						"eks.amazonaws.com/component": "coredns",
+					},
+				},
+			},
+		},
+	}
+
 	profileNotSelectingCoreDNSBecauseOfNamespace = []*api.FargateProfile{
 		{
 			Name: "not-selecting-coredns-because-of-namespace",
@@ -97,6 +111,10 @@ var _ = Describe("coredns", func() {
 			Expect(coredns.IsSchedulableOnFargate(multipleProfilesWithOneSelectingCoreDNS)).To(BeTrue())
 		})
 
+		It("should return true when a Fargate profile matches kube-system and has the CoreDNS component label", func() {
+			Expect(coredns.IsSchedulableOnFargate(profileSelectingCoreDNSWithComponentLabel)).To(BeTrue())
+		})
+
 		It("should return true when provided the default Fargate profile", func() {
 			cfg := api.NewClusterConfig()
 			cfg.SetDefaultFargateProfile()