Improve SubnetDHCPConfig validation rule (#976) (#978)

Subnet controller will update the SubnetSpec as the following when
either accessMode or ipv4SubnetSize is not provided.
```
spec:
  accessMode: Public
  ipv4SubnetSize: 64
  subnetDHCPConfig:{}
```
Thus we need another validation rule on subnetDHCPConfig to prevent
subnetDHCPConfig being updated from no mode specified to
DHCPServer/DHCPRelay mode.

Signed-off-by: Yanjun Zhou <[email protected]>

build/yaml/crd/vpc/crd.nsx.vmware.com_subnets.yaml

@@ -98,6 +98,10 @@ spec:
                         to other modes
                       rule: oldSelf!='DHCPDeactivated' || oldSelf==self
                 type: object
+                x-kubernetes-validations:
+                - message: subnetDHCPConfig cannot switch from DHCPDeactivated to
+                    other modes
+                  rule: has(oldSelf.mode) || !has(self.mode) || self.mode=='DHCPDeactivated'
             type: object
             x-kubernetes-validations:
             - message: subnetDHCPConfig cannot switch from DHCPDeactivated to other

build/yaml/crd/vpc/crd.nsx.vmware.com_subnetsets.yaml

@@ -88,6 +88,10 @@ spec:
                         to other modes
                       rule: oldSelf!='DHCPDeactivated' || oldSelf==self
                 type: object
+                x-kubernetes-validations:
+                - message: subnetDHCPConfig cannot switch from DHCPDeactivated to
+                    other modes
+                  rule: has(oldSelf.mode) || !has(self.mode) || self.mode=='DHCPDeactivated'
             type: object
             x-kubernetes-validations:
             - message: subnetDHCPConfig cannot switch from DHCPDeactivated to other

pkg/apis/vpc/v1alpha1/subnet_types.go

@@ -40,13 +40,15 @@ type SubnetSpec struct {
 	// +kubebuilder:validation:XValidation:rule="self == oldSelf",message="Value is immutable"
 	IPAddresses []string `json:"ipAddresses,omitempty"`
 
-	// DHCP mode of a SubnetSet cannot switch from DHCPDeactivated to DHCPServer or DHCPRelay.
+	// DHCP mode of a Subnet cannot switch from DHCPDeactivated to DHCPServer or DHCPRelay.
 	// If subnetDHCPConfig is not set, the DHCP mode is DHCPDeactivated by default.
-	// In order to enforce this rule, two XValidation rules are defined.
-	// The rule in SubnetSetSpec prevents the condition that subnetDHCPConfig is not set in
-	// old SubnetSetSpec while the new SubnetSetSpec specifies a field other than DHCPDeactivated.
-	// The rule in SubnetDHCPConfig prevents the mode changing from empty or
-	// DHCPDeactivated to DHCPServer or DHCPRelay.
+	// In order to enforce this rule, three XValidation rules are defined.
+	// The rule on SubnetSpec prevents the condition that subnetDHCPConfig is not set in
+	// old SubnetSpec while the new SubnetSpec specifies a Mode other than DHCPDeactivated.
+	// The rule on SubnetDHCPConfig prevents the condition that Mode is not set in old
+	// SubnetDHCPConfig while the new one specifies a Mode other than DHCPDeactivated.
+	// The rule on SubnetDHCPConfig.Mode prevents the Mode changing from DHCPDeactivated
+	// to DHCPServer or DHCPRelay.
 
 	// DHCP configuration for Subnet.
 	SubnetDHCPConfig SubnetDHCPConfig `json:"subnetDHCPConfig,omitempty"`
@@ -90,6 +92,7 @@ type SubnetList struct {
 }
 
 // SubnetDHCPConfig is DHCP configuration for Subnet.
+// +kubebuilder:validation:XValidation:rule="has(oldSelf.mode) || !has(self.mode) || self.mode=='DHCPDeactivated'", message="subnetDHCPConfig cannot switch from DHCPDeactivated to other modes"
 type SubnetDHCPConfig struct {
 	// DHCP Mode. DHCPDeactivated will be used if it is not defined.
 	// It cannot switch from DHCPDeactivated to DHCPServer or DHCPRelay.

pkg/apis/vpc/v1alpha1/subnetset_types.go

@@ -23,11 +23,13 @@ type SubnetSetSpec struct {
 	AccessMode AccessMode `json:"accessMode,omitempty"`
 	// DHCP mode of a SubnetSet cannot switch from DHCPDeactivated to DHCPServer or DHCPRelay.
 	// If subnetDHCPConfig is not set, the DHCP mode is DHCPDeactivated by default.
-	// In order to enforce this rule, two XValidation rules are defined.
-	// The rule in SubnetSetSpec prevents the condition that subnetDHCPConfig is not set in
-	// old SubnetSetSpec while the new SubnetSetSpec specifies a field other than DHCPDeactivated.
-	// The rule in SubnetDHCPConfig prevents the mode changing from empty or
-	// DHCPDeactivated to DHCPServer or DHCPRelay.
+	// In order to enforce this rule, three XValidation rules are defined.
+	// The rule on SubnetSetSpec prevents the condition that subnetDHCPConfig is not set in
+	// old SubnetSetSpec while the new SubnetSetSpec specifies a Mode other than DHCPDeactivated.
+	// The rule on SubnetDHCPConfig prevents the condition that Mode is not set in old
+	// SubnetDHCPConfig while the new one specifies a Mode other than DHCPDeactivated.
+	// The rule on SubnetDHCPConfig.Mode prevents the Mode changing from DHCPDeactivated
+	// to DHCPServer or DHCPRelay.
 
 	// Subnet DHCP configuration.
 	SubnetDHCPConfig SubnetDHCPConfig `json:"subnetDHCPConfig,omitempty"`