Merge pull request #4009 from spectrocloud/support-aks-custom-dns-prefix

Support for custom dns prefix for aks clusters
kubernetes-sigs · Oct 4, 2023 · 44cb72a · 44cb72a
2 parents 0406a5b + 24c7651
commit 44cb72a
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Showing 9 changed files with 209 additions and 3 deletions.
diff --git a/api/v1beta1/azuremanagedcontrolplane_default.go b/api/v1beta1/azuremanagedcontrolplane_default.go
@@ -164,3 +164,9 @@ func (m *AzureManagedControlPlane) setDefaultOIDCIssuerProfile() {
 		m.Spec.OIDCIssuerProfile.Enabled = ptr.To(false)
 	}
 }
+
+func (m *AzureManagedControlPlane) setDefaultDNSPrefix() {
+	if m.Spec.DNSPrefix == nil {
+		m.Spec.DNSPrefix = ptr.To(m.Name)
+	}
+}
diff --git a/api/v1beta1/azuremanagedcontrolplane_types.go b/api/v1beta1/azuremanagedcontrolplane_types.go
@@ -213,6 +213,11 @@ type AzureManagedControlPlaneSpec struct {
 	// OIDCIssuerProfile is the OIDC issuer profile of the Managed Cluster.
 	// +optional
 	OIDCIssuerProfile *OIDCIssuerProfile `json:"oidcIssuerProfile,omitempty"`
+
+	// DNSPrefix allows the user to customize dns prefix.
+	// Immutable.
+	// +optional
+	DNSPrefix *string `json:"dnsPrefix,omitempty"`
 }
 
 // HTTPProxyConfig is the HTTP proxy configuration for the cluster.

diff --git a/api/v1beta1/azuremanagedcontrolplane_webhook.go b/api/v1beta1/azuremanagedcontrolplane_webhook.go
@@ -108,6 +108,7 @@ func (mw *azureManagedControlPlaneWebhook) Default(ctx context.Context, obj runt
 	m.setDefaultSku()
 	m.setDefaultAutoScalerProfile()
 	m.setDefaultOIDCIssuerProfile()
+	m.setDefaultDNSPrefix()
 
 	return nil
 }
@@ -246,6 +247,14 @@ func (mw *azureManagedControlPlaneWebhook) ValidateUpdate(ctx context.Context, o
 		}
 	}
 
+	if err := webhookutils.ValidateImmutable(
+		field.NewPath("Spec", "DNSPrefix"),
+		m.Spec.DNSPrefix,
+		old.Spec.DNSPrefix,
+	); err != nil {
+		allErrs = append(allErrs, err)
+	}
+
 	// Consider removing this once moves out of preview
 	// Updating outboundType after cluster creation (PREVIEW)
 	// https://learn.microsoft.com/en-us/azure/aks/egress-outboundtype#updating-outboundtype-after-cluster-creation-preview
@@ -296,6 +305,7 @@ func (m *AzureManagedControlPlane) Validate(cli client.Client) error {
 		m.validateAutoScalerProfile,
 		m.validateIdentity,
 		m.validateNetworkPluginMode,
+		m.validateDNSPrefix,
 	}
 
 	var errs []error
@@ -308,6 +318,26 @@ func (m *AzureManagedControlPlane) Validate(cli client.Client) error {
 	return kerrors.NewAggregate(errs)
 }
 
+func (m *AzureManagedControlPlane) validateDNSPrefix(_ client.Client) error {
+	if m.Spec.DNSPrefix == nil {
+		return nil
+	}
+
+	// Regex pattern for DNS prefix validation
+	// 1. Between 1 and 54 characters long: {1,54}
+	// 2. Alphanumerics and hyphens: [a-zA-Z0-9-]
+	// 3. Start and end with alphanumeric: ^[a-zA-Z0-9].*[a-zA-Z0-9]$
+	pattern := `^[a-zA-Z0-9][a-zA-Z0-9-]{0,52}[a-zA-Z0-9]$`
+	regex := regexp.MustCompile(pattern)
+	if regex.MatchString(ptr.Deref(m.Spec.DNSPrefix, "")) {
+		return nil
+	}
+	allErrs := field.ErrorList{
+		field.Invalid(field.NewPath("Spec", "DNSPrefix"), *m.Spec.DNSPrefix, "DNSPrefix is invalid, does not match regex: "+pattern),
+	}
+	return kerrors.NewAggregate(allErrs.ToAggregate().Errors())
+}
+
 // validateVersion validates the Kubernetes version.
 func (m *AzureManagedControlPlane) validateVersion(_ client.Client) error {
 	if !kubeSemver.MatchString(m.Spec.Version) {

diff --git a/api/v1beta1/azuremanagedcontrolplane_webhook_test.go b/api/v1beta1/azuremanagedcontrolplane_webhook_test.go
@@ -59,6 +59,8 @@ func TestDefaultingWebhook(t *testing.T) {
 	g.Expect(amcp.Spec.SKU.Tier).To(Equal(FreeManagedControlPlaneTier))
 	g.Expect(amcp.Spec.Identity.Type).To(Equal(ManagedControlPlaneIdentityTypeSystemAssigned))
 	g.Expect(*amcp.Spec.OIDCIssuerProfile.Enabled).To(BeFalse())
+	g.Expect(amcp.Spec.DNSPrefix).ToNot(BeNil())
+	g.Expect(*amcp.Spec.DNSPrefix).To(Equal(amcp.Name))
 
 	t.Logf("Testing amcp defaulting webhook with baseline")
 	netPlug := "kubenet"
@@ -76,6 +78,7 @@ func TestDefaultingWebhook(t *testing.T) {
 	amcp.Spec.OIDCIssuerProfile = &OIDCIssuerProfile{
 		Enabled: ptr.To(true),
 	}
+	amcp.Spec.DNSPrefix = ptr.To("test-prefix")
 
 	err = mcpw.Default(context.Background(), amcp)
 	g.Expect(err).NotTo(HaveOccurred())
@@ -89,7 +92,8 @@ func TestDefaultingWebhook(t *testing.T) {
 	g.Expect(amcp.Spec.VirtualNetwork.Subnet.Name).To(Equal("fooSubnetName"))
 	g.Expect(amcp.Spec.SKU.Tier).To(Equal(StandardManagedControlPlaneTier))
 	g.Expect(*amcp.Spec.OIDCIssuerProfile.Enabled).To(BeTrue())
-
+	g.Expect(amcp.Spec.DNSPrefix).ToNot(BeNil())
+	g.Expect(*amcp.Spec.DNSPrefix).To(Equal("test-prefix"))
 	t.Logf("Testing amcp defaulting webhook with overlay")
 	amcp = &AzureManagedControlPlane{
 		ObjectMeta: metav1.ObjectMeta{
@@ -778,6 +782,76 @@ func TestAzureManagedControlPlane_ValidateCreate(t *testing.T) {
 			wantErr:  true,
 			errorLen: 1,
 		},
+		{
+			name: "Testing inValid DNSPrefix for starting with invalid characters",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("-thisi$"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "Testing inValid DNSPrefix with more then 54 characters",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("thisisaverylong$^clusternameconsistingofmorethan54characterswhichshouldbeinvalid"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "Testing inValid DNSPrefix with underscore",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("no_underscore"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "Testing inValid DNSPrefix with special characters",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("no-dollar$@%"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "Testing Valid DNSPrefix with hyphen characters",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("hyphen-allowed"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "Testing Valid DNSPrefix with hyphen characters",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("palette-test07"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "Testing valid DNSPrefix ",
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("thisisavlerylongclu7l0sternam3leconsistingofmorethan54"),
+					Version:   "v1.17.8",
+				},
+			},
+			wantErr: false,
+		},
 		{
 			name: "invalid name with microsoft",
 			amcp: &AzureManagedControlPlane{
@@ -1609,6 +1683,86 @@ func TestAzureManagedControlPlane_ValidateUpdate(t *testing.T) {
 			},
 			wantErr: false,
 		},
+		{
+			name: "AzureManagedControlPlane DNSPrefix is immutable error",
+			oldAMCP: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("capz-aks-1"),
+					Version:   "v1.18.0",
+				},
+			},
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("capz-aks"),
+					Version:   "v1.18.0",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "AzureManagedControlPlane DNSPrefix is immutable no error",
+			oldAMCP: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("capz-aks"),
+					Version:   "v1.18.0",
+				},
+			},
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("capz-aks"),
+					Version:   "v1.18.0",
+				},
+			},
+			wantErr: false,
+		},
+		{
+			name: "AzureManagedControlPlane DNSPrefix is immutable error nil -> capz-aks",
+			oldAMCP: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: nil,
+					Version:   "v1.18.0",
+				},
+			},
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To("capz-aks"),
+					Version:   "v1.18.0",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "AzureManagedControlPlane DNSPrefix is immutable error nil -> empty",
+			oldAMCP: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: nil,
+					Version:   "v1.18.0",
+				},
+			},
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: ptr.To(""),
+					Version:   "v1.18.0",
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "AzureManagedControlPlane DNSPrefix is immutable no error nil -> nil",
+			oldAMCP: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: nil,
+					Version:   "v1.18.0",
+				},
+			},
+			amcp: &AzureManagedControlPlane{
+				Spec: AzureManagedControlPlaneSpec{
+					DNSPrefix: nil,
+					Version:   "v1.18.0",
+				},
+			},
+			wantErr: false,
+		},
 	}
 	client := mockClient{ReturnError: false}
 	for _, tc := range tests {

diff --git a/api/v1beta1/zz_generated.deepcopy.go b/api/v1beta1/zz_generated.deepcopy.go
diff --git a/azure/scope/managedcontrolplane.go b/azure/scope/managedcontrolplane.go
@@ -482,6 +482,7 @@ func (s *ManagedControlPlaneScope) ManagedClusterSpec() azure.ResourceSpecGetter
 		Identity:                    s.ControlPlane.Spec.Identity,
 		KubeletUserAssignedIdentity: s.ControlPlane.Spec.KubeletUserAssignedIdentity,
 		NetworkPluginMode:           s.ControlPlane.Spec.NetworkPluginMode,
+		DNSPrefix:                   s.ControlPlane.Spec.DNSPrefix,
 	}
 
 	if s.ControlPlane.Spec.SSHPublicKey != nil {

diff --git a/azure/services/managedclusters/spec.go b/azure/services/managedclusters/spec.go
@@ -122,6 +122,9 @@ type ManagedClusterSpec struct {
 
 	// OIDCIssuerProfile is the OIDC issuer profile of the Managed Cluster.
 	OIDCIssuerProfile *OIDCIssuerProfile
+
+	// DNSPrefix allows the user to customize dns prefix.
+	DNSPrefix *string
 }
 
 // HTTPProxyConfig is the HTTP proxy configuration for the cluster.
@@ -326,7 +329,7 @@ func (s *ManagedClusterSpec) Parameters(ctx context.Context, existing interface{
 		Properties: &armcontainerservice.ManagedClusterProperties{
 			NodeResourceGroup: &s.NodeResourceGroup,
 			EnableRBAC:        ptr.To(true),
-			DNSPrefix:         &s.Name,
+			DNSPrefix:         s.DNSPrefix,
 			KubernetesVersion: &s.Version,
 
 			ServicePrincipalProfile: &armcontainerservice.ManagedClusterServicePrincipalProfile{

diff --git a/azure/services/managedclusters/spec_test.go b/azure/services/managedclusters/spec_test.go
@@ -589,7 +589,6 @@ func getSampleManagedCluster() armcontainerservice.ManagedCluster {
 	return armcontainerservice.ManagedCluster{
 		Properties: &armcontainerservice.ManagedClusterProperties{
 			KubernetesVersion: ptr.To("v1.22.0"),
-			DNSPrefix:         ptr.To("test-managedcluster"),
 			AgentPoolProfiles: []*armcontainerservice.ManagedClusterAgentPoolProfile{
 				{
 					Name:         ptr.To("test-agentpool-0"),

diff --git a/config/crd/bases/infrastructure.cluster.x-k8s.io_azuremanagedcontrolplanes.yaml b/config/crd/bases/infrastructure.cluster.x-k8s.io_azuremanagedcontrolplanes.yaml
@@ -239,6 +239,9 @@ spec:
                 - host
                 - port
                 type: object
+              dnsPrefix:
+                description: DNSPrefix allows the user to customize dns prefix. Immutable.
+                type: string
               dnsServiceIP:
                 description: DNSServiceIP is an IP address assigned to the Kubernetes
                   DNS service. It must be within the Kubernetes service address range