Add Azure Stack as a valid environment

Adds AzureStack as a valid cloud environment. The value
"HybridEnvironment" is the value provided by the Azure autorest
package. It would be possible to have a different user-facing
value, such as AzureStackCloud, but internally within the code
it is necessary to check for the value "HybridEnvironment"
returned by autorest. This commit opts to use a single value,
rather than separate user-facing and internal values.

Author: patrickdillon

api/v1beta1/types_class.go

@@ -48,6 +48,7 @@ type AzureClusterClassSpec struct {
 	// - GermanCloud: "AzureGermanCloud"
 	// - PublicCloud: "AzurePublicCloud"
 	// - USGovernmentCloud: "AzureUSGovernmentCloud"
+	// - StackCloud: "HybridEnvironment"
 	//
 	// Note that values other than the default must also be accompanied by corresponding changes to the
 	// aso-controller-settings Secret to configure ASO to refer to the non-Public cloud. ASO currently does
@@ -186,6 +187,7 @@ type AzureManagedControlPlaneClassSpec struct {
 	// - PublicCloud: "AzurePublicCloud"
 	// - USGovernmentCloud: "AzureUSGovernmentCloud"
 	//
+	//
 	// Note that values other than the default must also be accompanied by corresponding changes to the
 	// aso-controller-settings Secret to configure ASO to refer to the non-Public cloud. ASO currently does
 	// not support referring to multiple different clouds in a single installation. The following fields must

azure/defaults.go

@@ -45,6 +45,8 @@ const (
 	ChinaCloudName = "AzureChinaCloud"
 	// USGovernmentCloudName is the name of the Azure US Government cloud.
 	USGovernmentCloudName = "AzureUSGovernmentCloud"
+	// StackCloudName is the name for Azure Stack hybrid cloud environments.
+	StackCloudName = "HybridEnvironment"
 )
 
 const (