capi provider interface: add bootstrap delete hook

Adds a hook to execute provider-specific behvavior during
bootstrap destroy. This hook should be used to handle any
bootstrap resources that are not deleted in the default
behavior of deleting the capi machine.

The intended first use case of this is to delete aws
security rules for ssh to the bootstrap node. This
use case does not have any relationship to the
machine deletion; so I have opted for the simplest
execution of running this command serially before
the call to destroy the capi machine. If needed,
this command could be run post machine destroy or
even to run concurrently.

Author: patrickdillon

pkg/infrastructure/clusterapi/clusterapi.go

@@ -378,6 +378,17 @@ func (i *InfraProvider) DestroyBootstrap(ctx context.Context, dir string) error
 		}
 	}
 
+	if p, ok := i.impl.(BootstrapDestroyer); ok {
+		bootstrapDestoryInput := BootstrapDestroyInput{
+			Client:   sys.Client(),
+			Metadata: *metadata,
+		}
+
+		if err = p.DestroyBootstrap(ctx, bootstrapDestoryInput); err != nil {
+			return fmt.Errorf("failed during the destroy bootstrap hook: %w", err)
+		}
+	}
+
 	machineName := capiutils.GenerateBoostrapMachineName(metadata.InfraID)
 	machineNamespace := capiutils.Namespace
 	if err := sys.Client().Delete(ctx, &clusterv1.Machine{

pkg/infrastructure/clusterapi/types.go

@@ -10,6 +10,7 @@ import (
 	"github.com/openshift/installer/pkg/asset/machines"
 	"github.com/openshift/installer/pkg/asset/manifests"
 	"github.com/openshift/installer/pkg/asset/rhcos"
+	"github.com/openshift/installer/pkg/types"
 )
 
 // Provider is the base interface that cloud platforms
@@ -87,3 +88,15 @@ type PostProvisionInput struct {
 	InstallConfig *installconfig.InstallConfig
 	InfraID       string
 }
+
+// BootstrapDestroyer allows platform-specific behavior when
+// destroying bootstrap resources.
+type BootstrapDestroyer interface {
+	DestroyBootstrap(ctx context.Context, in BootstrapDestroyInput) error
+}
+
+// BootstrapDestroyInput collects args passed to the DestroyBootstrap hook.
+type BootstrapDestroyInput struct {
+	Client   client.Client
+	Metadata types.ClusterMetadata
+}