Replaces imports with v1alpha4 types

- Replace v1alpha3 imports with v1alpha4 ones
- Removes v1alpha2 types
  Updates PROJECT files for core and bootstrap
  Update the manifests to remove v1alpha2 types
  Remove refs of v1alpha2 from Makefile
- Removes v1alpha3 webhooks from manager
- Updates code-gen Makefile targets
  Before running the conversion-gen, we delete the existing generated
  files to ensure clean generation of API conversion code.

Signed-off-by: Sagar Muchhal <muchhals@vmware.com>
Co-authored-by: Vince Prignano <vince@vincepri.com>

Makefile

@@ -231,8 +231,8 @@ generate-go-core: $(CONTROLLER_GEN) $(CONVERSION_GEN)
 		paths=./$(EXP_DIR)/api/... \
 		paths=./$(EXP_DIR)/addons/api/... \
 		paths=./cmd/clusterctl/...
+	$(MAKE) clean-generated-conversions SRC_DIRS="./api/v1alpha3,./$(EXP_DIR)/api/v1alpha3,./$(EXP_DIR)/addons/api/v1alpha3"
 	$(CONVERSION_GEN) \
-		--input-dirs=./api/v1alpha2 \
 		--input-dirs=./api/v1alpha3 \
 		--input-dirs=./$(EXP_DIR)/api/v1alpha3 \
 		--input-dirs=./$(EXP_DIR)/addons/api/v1alpha3 \
@@ -246,8 +246,8 @@ generate-go-kubeadm-bootstrap: $(CONTROLLER_GEN) $(CONVERSION_GEN) ## Runs Go re
 		object:headerFile=./hack/boilerplate/boilerplate.generatego.txt \
 		paths=./bootstrap/kubeadm/api/... \
 		paths=./bootstrap/kubeadm/types/...
+	$(MAKE) clean-generated-conversions SRC_DIRS="./bootstrap/kubeadm/api"
 	$(CONVERSION_GEN) \
-		--input-dirs=./bootstrap/kubeadm/api/v1alpha2 \
 		--input-dirs=./bootstrap/kubeadm/api/v1alpha3 \
 		--build-tag=ignore_autogenerated_kubeadm_bootstrap_v1alpha3 \
 		--extra-peer-dirs=sigs.k8s.io/cluster-api/api/v1alpha3 \
@@ -259,6 +259,7 @@ generate-go-kubeadm-control-plane: $(CONTROLLER_GEN) $(CONVERSION_GEN) ## Runs G
 	$(CONTROLLER_GEN) \
 		object:headerFile=./hack/boilerplate/boilerplate.generatego.txt \
 		paths=./controlplane/kubeadm/api/...
+	$(MAKE) clean-generated-conversions SRC_DIRS="./controlplane/kubeadm/api"
 	$(CONVERSION_GEN) \
 		--input-dirs=./controlplane/kubeadm/api/v1alpha3 \
 		--build-tag=ignore_autogenerated_kubeadm_controlplane_v1alpha3 \
@@ -626,3 +627,6 @@ diagrams: ## Build proposal diagrams
 serve-book: ## Build and serve the book with live-reloading enabled
 	$(MAKE) -C docs/book serve
 
+.PHONY: clean-generated-conversions
+clean-generated-conversions: ## Remove files generated by conversion-gen from the mentioned dirs
+	(IFS=','; for i in $(SRC_DIRS); do find $$i -type f -name 'zz_generated.conversion*' -exec rm -f {} \;; done)

PROJECT

@@ -2,18 +2,6 @@ version: "2"
 domain: x-k8s.io
 repo: sigs.k8s.io/cluster-api
 resources:
-- group: cluster
-  version: v1alpha2
-  kind: Cluster
-- group: cluster
-  version: v1alpha2
-  kind: Machine
-- group: cluster
-  version: v1alpha2
-  kind: MachineSet
-- group: cluster
-  version: v1alpha2
-  kind: MachineDeployment
 - group: cluster
   version: v1alpha3
   kind: Cluster