NE-1323: Add AWS RoleARN for Shared VPC support

Adds the ability to specify a RoleARN to create Route 53 DNS records in a different AWS Account. Supports Shared VPC scenario. `api/v1beta1/externaldns_types.go`: Add RoleARN API `api/v1beta1/webhook_test.go`: Add RoleARN WebHook Validation test `api/v1beta1/zz_generated.deepcopy.go`: Generated `bundle/manifests/externaldns.olm.openshift.io_externaldnses.yaml`: Generated `config/crd/bases/externaldns.olm.openshift.io_externaldnses.yaml`: Generated `pkg/operator/controller/externaldns/credentials_request.go`: Add sts:AssumeRole to credential requests `pkg/operator/controller/externaldns/deployment_test.go`: Unit test `desiredExternalDNSDeployment` `pkg/operator/controller/externaldns/pod.go`: Add --aws-assume-role argument with RoleARN value
openshift · Jul 17, 2023 · b4e7cbc · b4e7cbc
1 parent 0cd8bee
commit b4e7cbc
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Showing 12 changed files with 243 additions and 7 deletions.
diff --git a/api/v1beta1/externaldns_types.go b/api/v1beta1/externaldns_types.go
@@ -254,9 +254,16 @@ type ExternalDNSAWSProviderOptions struct {
 	// https://github.com/kubernetes-sigs/external-dns/blob/master/docs/tutorials/aws.md
 	// for more information.
 	//
-	// +kubebuilder:validation:Required
-	// +required
+	// +kubebuilder:validation:Optional
+	// +optional
 	Credentials SecretReference `json:"credentials"`
+
+	// RoleARN contains the ARN of a IAM role that will be assumed when using the AWS API.
+	// It provides the ability to use a hosted zone in another AWS account.
+	//
+	// +kubebuilder:validation:Optional
+	// +optional
+	RoleARN *string `json:"roleARN,omitempty"`
 	// TODO: Additionally support access for:
 	// - kiam/kube2iam enabled clusters ("iam.amazonaws.com/role" POD's annotation to assume IAM role)
 	// - EKS clusters ("eks.amazonaws.com/role-arn" ServiceAccount's annotation to assume IAM role)

diff --git a/api/v1beta1/externaldns_webhook.go b/api/v1beta1/externaldns_webhook.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"regexp"
 
+	"github.com/aws/aws-sdk-go/aws/arn"
 	"k8s.io/apimachinery/pkg/runtime"
 
 	utilErrors "k8s.io/apimachinery/pkg/util/errors"
@@ -69,6 +70,7 @@ func (r *ExternalDNS) validate(old runtime.Object) error {
 		r.validateFilters(),
 		r.validateSources(old),
 		r.validateHostnameAnnotationPolicy(),
+		r.validateAWSRoleARN(),
 		r.validateProviderCredentials(),
 	})
 }
@@ -155,3 +157,13 @@ func (r *ExternalDNS) validateProviderCredentials() error {
 	}
 	return nil
 }
+
+func (r *ExternalDNS) validateAWSRoleARN() error {
+	// Ensure we have a valid arn if it is specified.
+	provider := r.Spec.Provider
+	if provider.AWS != nil && provider.AWS.RoleARN != nil && !arn.IsARN(*provider.AWS.RoleARN) {
+		return errors.New(fmt.Sprintf("arn %s is not a valid AWS ARN", *provider.AWS.RoleARN))
+	}
+
+	return nil
+}
diff --git a/api/v1beta1/webhook_test.go b/api/v1beta1/webhook_test.go
@@ -52,6 +52,29 @@ var _ = Describe("ExternalDNS admission webhook when platform is OCP", func() {
 				err := k8sClient.Create(context.Background(), resource)
 				Expect(err).Should(Succeed())
 			})
+			It("valid RoleARN", func() {
+				resource := makeExternalDNS("test-valid-rolearn-openshift", nil)
+				resource.Spec.Provider = ExternalDNSProvider{
+					Type: ProviderTypeAWS,
+					AWS: &ExternalDNSAWSProviderOptions{
+						RoleARN: pointer.String("arn:aws:iam::123456789012:role/foo"),
+					},
+				}
+				err := k8sClient.Create(context.Background(), resource)
+				Expect(err).Should(Succeed())
+			})
+			It("invalid RoleARN rejected", func() {
+				resource := makeExternalDNS("test-invalid-rolearn-openshift", nil)
+				resource.Spec.Provider = ExternalDNSProvider{
+					Type: ProviderTypeAWS,
+					AWS: &ExternalDNSAWSProviderOptions{
+						RoleARN: pointer.String("arn:aws:iam:bad123456789012:role/foo"),
+					},
+				}
+				err := k8sClient.Create(context.Background(), resource)
+				Expect(err).ShouldNot(Succeed())
+				Expect(err.Error()).Should(ContainSubstring(`arn arn:aws:iam:bad123456789012:role/foo is not a valid AWS ARN`))
+			})
 		})
 		Context("resource with Azure provider", func() {
 			It("ignores when provider Azure credentials are not specified", func() {
@@ -175,6 +198,31 @@ var _ = Describe("ExternalDNS admission webhook", func() {
 			Expect(err).ShouldNot(Succeed())
 			Expect(err.Error()).Should(ContainSubstring("credentials secret must be specified when provider type is AWS"))
 		})
+		It("valid RoleARN", func() {
+			resource := makeExternalDNS("test-valid-rolearn", nil)
+			resource.Spec.Provider = ExternalDNSProvider{
+				Type: ProviderTypeAWS,
+				AWS: &ExternalDNSAWSProviderOptions{
+					RoleARN:     pointer.String("arn:aws:iam::123456789012:role/foo"),
+					Credentials: SecretReference{Name: "credentials"},
+				},
+			}
+			err := k8sClient.Create(context.Background(), resource)
+			Expect(err).Should(Succeed())
+		})
+		It("invalid RoleARN rejected", func() {
+			resource := makeExternalDNS("test-invalid-rolearn", nil)
+			resource.Spec.Provider = ExternalDNSProvider{
+				Type: ProviderTypeAWS,
+				AWS: &ExternalDNSAWSProviderOptions{
+					RoleARN:     pointer.String("arn:aws:iam:bad123456789012:role/foo"),
+					Credentials: SecretReference{Name: "credentials"},
+				},
+			}
+			err := k8sClient.Create(context.Background(), resource)
+			Expect(err).ShouldNot(Succeed())
+			Expect(err.Error()).Should(ContainSubstring(`arn arn:aws:iam:bad123456789012:role/foo is not a valid AWS ARN`))
+		})
 	})
 
 	Context("resource with Azure provider", func() {

diff --git a/api/v1beta1/zz_generated.deepcopy.go b/api/v1beta1/zz_generated.deepcopy.go
diff --git a/bundle/manifests/externaldns.olm.openshift.io_externaldnses.yaml b/bundle/manifests/externaldns.olm.openshift.io_externaldnses.yaml
@@ -582,8 +582,11 @@ spec:
                         required:
                         - name
                         type: object
-                    required:
-                    - credentials
+                      roleARN:
+                        description: RoleARN contains the ARN of a IAM role that will
+                          be assumed when using the AWS API. It provides the ability
+                          to use a hosted zone in another AWS account.
+                        type: string
                     type: object
                   azure:
                     description: Azure describes provider configuration options specific

diff --git a/config/crd/bases/externaldns.olm.openshift.io_externaldnses.yaml b/config/crd/bases/externaldns.olm.openshift.io_externaldnses.yaml
@@ -584,8 +584,11 @@ spec:
                         required:
                         - name
                         type: object
-                    required:
-                    - credentials
+                      roleARN:
+                        description: RoleARN contains the ARN of a IAM role that will
+                          be assumed when using the AWS API. It provides the ability
+                          to use a hosted zone in another AWS account.
+                        type: string
                     type: object
                   azure:
                     description: Azure describes provider configuration options specific

diff --git a/pkg/operator/controller/externaldns/credentials_request.go b/pkg/operator/controller/externaldns/credentials_request.go
@@ -248,6 +248,7 @@ func createProviderConfig(externalDNS *operatorv1beta1.ExternalDNS, platformStat
 							"route53:ListHostedZones",
 							"route53:ListResourceRecordSets",
 							"tag:GetResources",
+							"sts:AssumeRole",
 						},
 						Resource: "*",
 					},

diff --git a/pkg/operator/controller/externaldns/credentials_request_test.go b/pkg/operator/controller/externaldns/credentials_request_test.go
@@ -285,6 +285,7 @@ func desiredAWSProviderSpec() runtime.Object {
 					"route53:ListHostedZones",
 					"route53:ListResourceRecordSets",
 					"tag:GetResources",
+					"sts:AssumeRole",
 				},
 				Resource: "*",
 			},
@@ -311,6 +312,7 @@ func desiredAWSProviderSpecGovARN() runtime.Object {
 					"route53:ListHostedZones",
 					"route53:ListResourceRecordSets",
 					"tag:GetResources",
+					"sts:AssumeRole",
 				},
 				Resource: "*",
 			},

diff --git a/pkg/operator/controller/externaldns/deployment_test.go b/pkg/operator/controller/externaldns/deployment_test.go
@@ -1783,6 +1783,55 @@ func TestDesiredExternalDNSDeployment(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:             "RoleARN set AWS Route",
+			inputExternalDNS: testAWSExternalDNSRoleARN(operatorv1beta1.SourceTypeRoute, "arn:aws:iam:123456789012:role/foo"),
+			expectedTemplatePodSpec: corev1.PodSpec{
+				ServiceAccountName: test.OperandName,
+				NodeSelector: map[string]string{
+					osLabel:             linuxOS,
+					masterNodeRoleLabel: "",
+				},
+				Tolerations: []corev1.Toleration{
+					{
+						Key:      masterNodeRoleLabel,
+						Operator: corev1.TolerationOpExists,
+						Effect:   corev1.TaintEffectNoSchedule,
+					},
+				},
+				Containers: []corev1.Container{
+					{
+						Name:  ExternalDNSContainerName,
+						Image: test.OperandImage,
+						Args: []string{
+							"--aws-assume-role=arn:aws:iam:123456789012:role/foo",
+							"--metrics-address=127.0.0.1:7979",
+							"--txt-owner-id=external-dns-test",
+							"--zone-id-filter=my-dns-public-zone",
+							"--provider=aws",
+							"--source=openshift-route",
+							"--policy=sync",
+							"--registry=txt",
+							"--log-level=debug",
+							"--ignore-hostname-annotation",
+							`--fqdn-template={{""}}`,
+							"--txt-prefix=external-dns-",
+						},
+						SecurityContext: &corev1.SecurityContext{
+							Capabilities: &corev1.Capabilities{
+								Drop: []corev1.Capability{allCapabilities},
+							},
+							Privileged:               pointer.Bool(false),
+							RunAsNonRoot:             pointer.Bool(true),
+							AllowPrivilegeEscalation: pointer.Bool(false),
+							SeccompProfile: &corev1.SeccompProfile{
+								Type: corev1.SeccompProfileTypeRuntimeDefault,
+							},
+						},
+					},
+				},
+			},
+		},
 		{
 			name:             "Nominal Azure Route",
 			inputSecretName:  azureSecret,
@@ -5317,6 +5366,14 @@ func testAWSExternalDNSDomainFilter(zones []string, source operatorv1beta1.Exter
 	return extdns
 }
 
+func testAWSExternalDNSRoleARN(source operatorv1beta1.ExternalDNSSourceType, roleARN string) *operatorv1beta1.ExternalDNS {
+	extdns := testCreateDNSFromSourceWRTCloudProvider(source, operatorv1beta1.ProviderTypeAWS, nil, "")
+	extdns.Spec.Provider.AWS = &operatorv1beta1.ExternalDNSAWSProviderOptions{
+		RoleARN: pointer.String(roleARN),
+	}
+	return extdns
+}
+
 func testPlatformStatusGCP(projectID string) *configv1.PlatformStatus {
 	return &configv1.PlatformStatus{
 		Type: configv1.GCPPlatformType,

diff --git a/pkg/operator/controller/externaldns/pod.go b/pkg/operator/controller/externaldns/pod.go
@@ -194,6 +194,10 @@ func (b *externalDNSContainerBuilder) fillProviderAgnosticFields(seq int, zone s
 		args = append(args, "--ignore-hostname-annotation")
 	}
 
+	if b.externalDNS.Spec.Provider.AWS != nil && b.externalDNS.Spec.Provider.AWS.RoleARN != nil {
+		args = append(args, fmt.Sprintf("--aws-assume-role=%s", *b.externalDNS.Spec.Provider.AWS.RoleARN))
+	}
+
 	if len(b.externalDNS.Spec.Source.FQDNTemplate) > 0 {
 		args = append(args, fmt.Sprintf("--fqdn-template=%s", strings.Join(b.externalDNS.Spec.Source.FQDNTemplate, ",")))
 	} else {

diff --git a/vendor/github.com/aws/aws-sdk-go/aws/arn/arn.go b/vendor/github.com/aws/aws-sdk-go/aws/arn/arn.go
diff --git a/vendor/modules.txt b/vendor/modules.txt
@@ -39,6 +39,7 @@ github.com/asaskevich/govalidator
 # github.com/aws/aws-sdk-go v1.41.6
 ## explicit; go 1.11
 github.com/aws/aws-sdk-go/aws
+github.com/aws/aws-sdk-go/aws/arn
 github.com/aws/aws-sdk-go/aws/awserr
 github.com/aws/aws-sdk-go/aws/awsutil
 github.com/aws/aws-sdk-go/aws/client