Use go install instead of go get in Makefile

Makefile

@@ -16,16 +16,20 @@ BUILD_ARGS ?=
 # Architectures to build images for.
 BUILD_PLATFORMS ?= linux/amd64
 
+# Architecture to use envtest with
+ENVTEST_ARCH ?= amd64
+
 all: manager
 
 # Download the envtest binaries to testbin
 ENVTEST_ASSETS_DIR=$(shell pwd)/testbin
 ENVTEST_KUBERNETES_VERSION?=latest
 install-envtest: setup-envtest
-	$(SETUP_ENVTEST) use $(ENVTEST_KUBERNETES_VERSION) --bin-dir=$(ENVTEST_ASSETS_DIR)
+	mkdir -p ${ENVTEST_ASSETS_DIR}
+	$(ENVTEST) use $(ENVTEST_KUBERNETES_VERSION) --arch=$(ENVTEST_ARCH) --bin-dir=$(ENVTEST_ASSETS_DIR)
 
 # Run controller tests
-KUBEBUILDER_ASSETS?="$(shell $(SETUP_ENVTEST) use -i $(ENVTEST_KUBERNETES_VERSION) --bin-dir=$(ENVTEST_ASSETS_DIR) -p path)"
+KUBEBUILDER_ASSETS?="$(shell $(ENVTEST) --arch=$(ENVTEST_ARCH) use -i $(ENVTEST_KUBERNETES_VERSION) --bin-dir=$(ENVTEST_ASSETS_DIR) -p path)"
 test: generate fmt vet manifests api-docs download-crd-deps install-envtest
 	KUBEBUILDER_ASSETS=$(KUBEBUILDER_ASSETS) go test ./controllers/...  -v -coverprofile cover.out
 
@@ -76,7 +80,7 @@ manifests: controller-gen
 
 # Generate API reference documentation
 api-docs: gen-crd-api-reference-docs
-	$(API_REF_GEN) -api-dir=./api/v1beta2 -config=./hack/api-docs/config.json -template-dir=./hack/api-docs/template -out-file=./docs/api/kustomize.md
+	$(GEN_CRD_API_REFERENCE_DOCS) -api-dir=./api/v1beta2 -config=./hack/api-docs/config.json -template-dir=./hack/api-docs/template -out-file=./docs/api/kustomize.md
 
 # Run go mod tidy
 tidy:
@@ -113,50 +117,33 @@ docker-push:
 docker-deploy:
 	kubectl -n flux-system set image deployment/kustomize-controller manager=${IMG}
 
-# find or download controller-gen
-# download controller-gen if necessary
-controller-gen:
-ifeq (, $(shell which controller-gen))
-	@{ \
-	set -e ;\
-	CONTROLLER_GEN_TMP_DIR=$$(mktemp -d) ;\
-	cd $$CONTROLLER_GEN_TMP_DIR ;\
-	go mod init tmp ;\
-	go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.7.0 ;\
-	rm -rf $$CONTROLLER_GEN_TMP_DIR ;\
-	}
-CONTROLLER_GEN=$(GOBIN)/controller-gen
-else
-CONTROLLER_GEN=$(shell which controller-gen)
-endif
+# Find or download controller-gen
+CONTROLLER_GEN = $(shell pwd)/bin/controller-gen
+.PHONY: controller-gen
+controller-gen: ## Download controller-gen locally if necessary.
+	$(call go-install-tool,$(CONTROLLER_GEN),sigs.k8s.io/controller-tools/cmd/controller-gen@v0.7.0)
 
 # Find or download gen-crd-api-reference-docs
+GEN_CRD_API_REFERENCE_DOCS = $(shell pwd)/bin/gen-crd-api-reference-docs
+.PHONY: gen-crd-api-reference-docs
 gen-crd-api-reference-docs:
-ifeq (, $(shell which gen-crd-api-reference-docs))
-	@{ \
-	set -e ;\
-	API_REF_GEN_TMP_DIR=$$(mktemp -d) ;\
-	cd $$API_REF_GEN_TMP_DIR ;\
-	go mod init tmp ;\
-	go get github.com/ahmetb/gen-crd-api-reference-docs@v0.2.0 ;\
-	rm -rf $$API_REF_GEN_TMP_DIR ;\
-	}
-API_REF_GEN=$(GOBIN)/gen-crd-api-reference-docs
-else
-API_REF_GEN=$(shell which gen-crd-api-reference-docs)
-endif
-
-setup-envtest:
-ifeq (, $(shell which setup-envtest))
-	@{ \
-	set -e ;\
-	SETUP_ENVTEST_TMP_DIR=$$(mktemp -d) ;\
-	cd $$SETUP_ENVTEST_TMP_DIR ;\
-	go mod init tmp ;\
-	go get sigs.k8s.io/controller-runtime/tools/setup-envtest@latest ;\
-	rm -rf $$SETUP_ENVTEST_TMP_DIR ;\
-	}
-SETUP_ENVTEST=$(GOBIN)/setup-envtest
-else
-SETUP_ENVTEST=$(shell which setup-envtest)
-endif
+	$(call go-install-tool,$(GEN_CRD_API_REFERENCE_DOCS),github.com/ahmetb/gen-crd-api-reference-docs@v0.3.0)
+
+ENVTEST = $(shell pwd)/bin/setup-envtest
+.PHONY: envtest
+setup-envtest: ## Download envtest-setup locally if necessary.
+	$(call go-install-tool,$(ENVTEST),sigs.k8s.io/controller-runtime/tools/setup-envtest@latest)
+
+# go-install-tool will 'go install' any package $2 and install it to $1.
+PROJECT_DIR := $(shell dirname $(abspath $(lastword $(MAKEFILE_LIST))))
+define go-install-tool
+@[ -f $(1) ] || { \
+set -e ;\
+TMP_DIR=$$(mktemp -d) ;\
+cd $$TMP_DIR ;\
+go mod init tmp ;\
+echo "Downloading $(2)" ;\
+GOBIN=$(PROJECT_DIR)/bin go install $(2) ;\
+rm -rf $$TMP_DIR ;\
+}
+endef