introduce runtime-openapi-gen to generate openapi spec on release

* openapi-gen: modified upstream openapi-gen to generate zz_generated.openapi.go files
* runtime-openapi-gen consumes runtime SDK catalog and generated openapi spec to generate openapi yaml spec

Co-authored-by: Stefan Bueringer <[email protected]>
Co-authored-by: Christian Schlotter <[email protected]>

.golangci.yml

@@ -263,6 +263,7 @@ run:
   - e2e
   skip-files:
   - "zz_generated.*\\.go$"
+  - "vendored_openapi\\.go$"
   skip-dirs:
   - third_party
   allow-parallel-runners: true

Makefile

@@ -118,6 +118,16 @@ KPROMO_PKG := sigs.k8s.io/promo-tools/v3/cmd/kpromo
 CONVERSION_VERIFIER_BIN := conversion-verifier
 CONVERSION_VERIFIER := $(abspath $(TOOLS_BIN_DIR)/$(CONVERSION_VERIFIER_BIN))
 
+OPENAPI_GEN_VER := 5e7f5fd
+OPENAPI_GEN_BIN := openapi-gen
+# We are intentionally using the binary without version suffix, to avoid the version
+# in generated files.
+OPENAPI_GEN := $(abspath $(TOOLS_BIN_DIR)/$(OPENAPI_GEN_BIN))
+OPENAPI_GEN_PKG := k8s.io/kube-openapi/cmd/openapi-gen
+
+RUNTIME_OPENAPI_GEN_BIN := runtime-openapi-gen
+RUNTIME_OPENAPI_GEN := $(abspath $(TOOLS_BIN_DIR)/$(RUNTIME_OPENAPI_GEN_BIN))
+
 TILT_PREPARE_BIN := tilt-prepare
 TILT_PREPARE := $(abspath $(TOOLS_BIN_DIR)/$(TILT_PREPARE_BIN))
 
@@ -179,8 +189,8 @@ help:  # Display this help
 ALL_GENERATE_MODULES = core kubeadm-bootstrap kubeadm-control-plane
 
 .PHONY: generate
-generate: ## Run all generate-manifests-*, generate-go-deepcopy-*, generate-go-conversions-* targets
-	$(MAKE) generate-modules generate-manifests generate-go-deepcopy generate-go-conversions
+generate: ## Run all generate-manifests-*, generate-go-deepcopy-*, generate-go-conversions-* and generate-go-openapi targets
+	$(MAKE) generate-modules generate-manifests generate-go-deepcopy generate-go-conversions generate-go-openapi
 	$(MAKE) -C $(CAPD_DIR) generate
 
 .PHONY: generate-manifests
@@ -328,6 +338,18 @@ generate-go-conversions-kubeadm-control-plane: $(CONVERSION_GEN) ## Generate con
 		--output-file-base=zz_generated.conversion $(CONVERSION_GEN_OUTPUT_BASE) \
 		--go-header-file=./hack/boilerplate/boilerplate.generatego.txt
 
+.PHONY: generate-go-openapi
+generate-go-openapi: $(OPENAPI_GEN) $(CONTROLLER_GEN) ## Generate openapi go code for runtime SDK
+	@for pkg in "api/v1beta1" "$(EXP_DIR)/runtime/hooks/api/v1alpha1"; do \
+		$(MAKE) clean-generated-openapi-definitions SRC_DIRS="./$${pkg}"; \
+		echo "** Generating openapi schema for types in ./$${pkg} **"; \
+		$(OPENAPI_GEN) \
+			--input-dirs=./$${pkg} \
+			--output-file-base=zz_generated.openapi \
+			--output-package=sigs.k8s.io/cluster-api/$${pkg} \
+			--go-header-file=./hack/boilerplate/boilerplate.generatego.txt; \
+	done
+
 .PHONY: generate-modules
 generate-modules: ## Run go mod tidy to ensure modules are up to date
 	go mod tidy
@@ -590,7 +612,7 @@ manifest-modification: # Set the manifest images to the staging/production bucke
 	$(MAKE) set-manifest-pull-policy PULL_POLICY=IfNotPresent TARGET_RESOURCE="./controlplane/kubeadm/config/default/manager_pull_policy.yaml"
 
 .PHONY: release-manifests
-release-manifests: $(RELEASE_DIR) $(KUSTOMIZE) ## Build the manifests to publish with a release
+release-manifests: $(RELEASE_DIR) $(KUSTOMIZE) $(RUNTIME_OPENAPI_GEN) ## Build the manifests to publish with a release
 	# Build core-components.
 	$(KUSTOMIZE) build config/default > $(RELEASE_DIR)/core-components.yaml
 	# Build bootstrap-components.
@@ -607,6 +629,9 @@ release-manifests: $(RELEASE_DIR) $(KUSTOMIZE) ## Build the manifests to publish
 	# Add metadata to the release artifacts
 	cp metadata.yaml $(RELEASE_DIR)/metadata.yaml
 
+	# Generate OpenAPI specification.
+	$(RUNTIME_OPENAPI_GEN) --version $(RELEASE_TAG) --output-file $(RELEASE_DIR)/runtime-sdk-openapi.yaml
+
 .PHONY: release-manifests-dev
 release-manifests-dev: ## Build the development manifests and copies them in the release folder
 	# Release CAPD components and add them to the release dir
@@ -761,6 +786,10 @@ clean-release-git: ## Restores the git files usually modified during a release
 clean-generated-conversions: ## Remove files generated by conversion-gen from the mentioned dirs. Example SRC_DIRS="./api/v1alpha4"
 	(IFS=','; for i in $(SRC_DIRS); do find $$i -type f -name 'zz_generated.conversion*' -exec rm -f {} \;; done)
 
+.PHONY: clean-generated-openapi-definitions
+clean-generated-openapi-definitions: ## Remove files generated by openapi-gen from the mentioned dirs. Example SRC_DIRS="./api/v1alpha4"
+	(IFS=','; for i in $(SRC_DIRS); do find $$i -type f -name 'zz_generated.openapi*' -exec rm -f {} \;; done)
+
 ## --------------------------------------
 ## Hack / Tools
 ## --------------------------------------
@@ -773,6 +802,12 @@ $(CONTROLLER_GEN_BIN): $(CONTROLLER_GEN) ## Build a local copy of controller-gen
 .PHONY: $(CONVERSION_GEN_BIN)
 $(CONVERSION_GEN_BIN): $(CONVERSION_GEN) ## Build a local copy of conversion-gen.
 
+.PHONY: $(OPENAPI_GEN_BIN)
+$(OPENAPI_GEN_BIN): $(OPENAPI_GEN) ## Build a local copy of openapi-gen.
+
+.PHONY: $(RUNTIME_OPENAPI_GEN_BIN)
+$(RUNTIME_OPENAPI_GEN_BIN): $(RUNTIME_OPENAPI_GEN) ## Build a local copy of runtime-openapi-gen.
+
 .PHONY: $(CONVERSION_VERIFIER_BIN)
 $(CONVERSION_VERIFIER_BIN): $(CONVERSION_VERIFIER) ## Build a local copy of conversion-verifier.
 
@@ -812,6 +847,15 @@ $(CONVERSION_GEN): # Build conversion-gen from tools folder.
 $(CONVERSION_VERIFIER): $(TOOLS_DIR)/go.mod # Build conversion-verifier from tools folder.
 	cd $(TOOLS_DIR); go build -tags=tools -o $(BIN_DIR)/$(CONVERSION_VERIFIER_BIN) sigs.k8s.io/cluster-api/hack/tools/conversion-verifier
 
+.PHONY: $(OPENAPI_GEN)
+$(OPENAPI_GEN): # Build openapi-gen from tools folder.
+	GOBIN=$(TOOLS_BIN_DIR) $(GO_INSTALL) $(OPENAPI_GEN_PKG) $(OPENAPI_GEN_BIN) $(OPENAPI_GEN_VER)
+
+## We are forcing a rebuilt of runtime-openapi-gen via PHONY so that we're always using an up-to-date version.
+.PHONY: $(RUNTIME_OPENAPI_GEN)
+$(RUNTIME_OPENAPI_GEN): $(TOOLS_DIR)/go.mod # Build openapi-gen from tools folder.
+	cd $(TOOLS_DIR); go build -tags=tools -o $(BIN_DIR)/$(RUNTIME_OPENAPI_GEN_BIN) sigs.k8s.io/cluster-api/hack/tools/runtime-openapi-gen
+
 $(GOTESTSUM): # Build gotestsum from tools folder.
 	GOBIN=$(TOOLS_BIN_DIR) $(GO_INSTALL) $(GOTESTSUM_PKG) $(GOTESTSUM_BIN) $(GOTESTSUM_VER)
 

api/v1beta1/doc.go

@@ -15,4 +15,5 @@ limitations under the License.
 */
 
 // Package v1beta1 contains the v1beta1 API implementation.
+// +k8s:openapi-gen=true
 package v1beta1