Add initial widget example

.dockerignore

@@ -0,0 +1,4 @@
+# More info: https://docs.docker.com/engine/reference/builder/#dockerignore-file
+# Ignore build and test binaries.
+bin/
+testbin/

.gitignore

@@ -18,3 +18,5 @@ vendor/
 .idea
 
 hack/tools
+
+bin/

Dockerfile

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+# Build the manager binary
+FROM golang:1.17 as builder
+
+WORKDIR /workspace
+# Copy the Go Modules manifests
+COPY go.mod go.mod
+COPY go.sum go.sum
+# cache deps before building and copying source so that we don't need to re-download as much
+# and so that source changes don't invalidate our downloaded layer
+RUN go mod download
+
+# Copy the go source
+COPY main.go main.go
+COPY api/ api/
+COPY controllers/ controllers/
+
+# Build
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
+
+# Use distroless as minimal base image to package the manager binary
+# Refer to https://github.com/GoogleContainerTools/distroless for more details
+FROM gcr.io/distroless/static:nonroot
+WORKDIR /
+COPY --from=builder /workspace/manager .
+USER 65532:65532
+
+ENTRYPOINT ["/manager"]

Makefile

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+
+# Image URL to use all building/pushing image targets
+IMG ?= controller:latest
+# ENVTEST_K8S_VERSION refers to the version of kubebuilder assets to be downloaded by envtest binary.
+ENVTEST_K8S_VERSION = 1.23
+
+# Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
+ifeq (,$(shell go env GOBIN))
+GOBIN=$(shell go env GOPATH)/bin
+else
+GOBIN=$(shell go env GOBIN)
+endif
+
+# Setting SHELL to bash allows bash commands to be executed by recipes.
+# This is a requirement for 'setup-envtest.sh' in the test target.
+# Options are set to exit when a recipe line exits non-zero or a piped command fails.
+SHELL = /usr/bin/env bash -o pipefail
+.SHELLFLAGS = -ec
+
+.PHONY: all
+all: build
+
+# kcp specific
+APIEXPORT_PREFIX ?= today
+
+##@ General
+
+# The help target prints out all targets with their descriptions organized
+# beneath their categories. The categories are represented by '##@' and the
+# target descriptions by '##'. The awk commands is responsible for reading the
+# entire set of makefiles included in this invocation, looking for lines of the
+# file as xyz: ## something, and then pretty-format the target and help. Then,
+# if there's a line with ##@ something, that gets pretty-printed as a category.
+# More info on the usage of ANSI control characters for terminal formatting:
+# https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_parameters
+# More info on the awk command:
+# http://linuxcommand.org/lc3_adv_awk.php
+
+.PHONY: help
+help: ## Display this help.
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n"} /^[a-zA-Z_0-9-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+
+##@ Development
+
+.PHONY: manifests
+manifests: controller-gen ## Generate WebhookConfiguration, ClusterRole and CustomResourceDefinition objects.
+	$(CONTROLLER_GEN) rbac:roleName=manager-role crd webhook paths="./..." output:crd:artifacts:config=config/crd/bases
+
+.PHONY: apiresourceschemas
+apiresourceschemas: kustomize ## Convert CRDs from config/crds to APIResourceSchemas. Specify APIEXPORT_PREFIX as needed.
+	$(KUSTOMIZE) build config/crd | kubectl kcp crd snapshot -f - --prefix $(APIEXPORT_PREFIX) > config/kcp/$(APIEXPORT_PREFIX).apiresourceschemas.yaml
+
+.PHONY: generate
+generate: controller-gen ## Generate code containing DeepCopy, DeepCopyInto, and DeepCopyObject method implementations.
+	$(CONTROLLER_GEN) object:headerFile="hack/boilerplate.go.txt" paths="./..."
+
+.PHONY: fmt
+fmt: ## Run go fmt against code.
+	go fmt ./...
+
+.PHONY: vet
+vet: ## Run go vet against code.
+	go vet ./...
+
+.PHONY: test
+test: manifests generate fmt vet envtest ## Run tests.
+	KUBEBUILDER_ASSETS="$(shell $(ENVTEST) use $(ENVTEST_K8S_VERSION) -p path)" go test ./... -coverprofile cover.out
+
+##@ Build
+
+.PHONY: build
+build: generate fmt vet ## Build manager binary.
+	go build -o bin/manager main.go
+
+NAME_PREFIX ?= controller-runtime-example-
+APIEXPORT_NAME ?= data.my.domain
+
+.PHONY: run
+run: manifests generate fmt vet ## Run a controller from your host.
+	go run ./main.go $(NAME_PREFIX)$(APIEXPORT_NAME)
+
+.PHONY: docker-build
+docker-build: test ## Build docker image with the manager.
+	docker build -t ${IMG} .
+
+.PHONY: docker-push
+docker-push: ## Push docker image with the manager.
+	docker push ${IMG}
+
+##@ Deployment
+
+ifndef ignore-not-found
+  ignore-not-found = false
+endif
+
+.PHONY: install
+install: manifests kustomize ## Install APIResourceSchemas and APIExport into kcp (using $KUBECONFIG or ~/.kube/config).
+	kustomize build config/kcp | kubectl apply -f -
+
+.PHONY: uninstall
+uninstall: manifests kustomize ## Uninstall APIResourceSchemas and APIExport from kcp (using $KUBECONFIG or ~/.kube/config). Call with ignore-not-found=true to ignore resource not found errors during deletion.
+	kustomize build config/kcp | kubectl delete --ignore-not-found=$(ignore-not-found) -f -
+
+.PHONY: deploy
+deploy: manifests kustomize ## Deploy controller
+	cd config/manager && $(KUSTOMIZE) edit set image controller=${IMG}
+	$(KUSTOMIZE) build config/default | kubectl apply -f -
+
+.PHONY: undeploy
+undeploy: ## Undeploy controller. Call with ignore-not-found=true to ignore resource not found errors during deletion.
+	$(KUSTOMIZE) build config/default | kubectl delete --ignore-not-found=$(ignore-not-found) -f -
+
+##@ Build Dependencies
+
+## Location to install dependencies to
+LOCALBIN ?= $(shell pwd)/bin
+$(LOCALBIN):
+	mkdir -p $(LOCALBIN)
+
+## Tool Binaries
+KUSTOMIZE ?= $(LOCALBIN)/kustomize
+CONTROLLER_GEN ?= $(LOCALBIN)/controller-gen
+ENVTEST ?= $(LOCALBIN)/setup-envtest
+
+## Tool Versions
+KUSTOMIZE_VERSION ?= v3.8.7
+CONTROLLER_TOOLS_VERSION ?= v0.8.0
+
+KUSTOMIZE_INSTALL_SCRIPT ?= "https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/hack/install_kustomize.sh"
+.PHONY: kustomize
+kustomize: $(KUSTOMIZE) ## Download kustomize locally if necessary.
+$(KUSTOMIZE): $(LOCALBIN)
+	curl -s $(KUSTOMIZE_INSTALL_SCRIPT) | bash -s -- $(subst v,,$(KUSTOMIZE_VERSION)) $(LOCALBIN)
+
+.PHONY: controller-gen
+controller-gen: $(CONTROLLER_GEN) ## Download controller-gen locally if necessary.
+$(CONTROLLER_GEN): $(LOCALBIN)
+	GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-tools/cmd/controller-gen@$(CONTROLLER_TOOLS_VERSION)
+
+.PHONY: envtest
+envtest: $(ENVTEST) ## Download envtest-setup locally if necessary.
+$(ENVTEST): $(LOCALBIN)
+	GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-runtime/tools/setup-envtest@latest

PROJECT

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+domain: my.domain
+layout:
+- go.kubebuilder.io/v3
+projectName: controller-runtime-example
+repo: github.com/kcp-dev/controller-runtime-example
+resources:
+- api:
+    crdVersion: v1
+    namespaced: true
+  controller: true
+  domain: my.domain
+  group: data
+  kind: Widget
+  path: github.com/kcp-dev/controller-runtime-example/api/v1alpha1
+  version: v1alpha1
+version: "3"

README.md

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+# controller-runtime-example
+An example project that is multi-cluster aware and works with [kcp](https://github.com/kcp-dev/kcp)
+
+## Description
+This repository contains an example project that works with APIExports and multiple kcp workspaces. It demonstrates
+two reconcilers:
+
+1. ConfigMap
+   1. Get a ConfigMap for the key from the queue, from the correct logical cluster
+   2. If the ConfigMap has labels["name"], set labels["response"] = "hello-$name" and save the changes
+   3. List all ConfigMaps in the logical cluster and log each one's namespace and name
+   4. If the ConfigMap from step 1 has data["namespace"] set, create a namespace whose name is the data value.
+   5. If the ConfigMap from step 1 has data["secretData"] set, create a secret in the same namespace as the ConfigMap,
+      with an owner reference to the ConfigMap, and data["dataFromCM"] set to the data value.
+
+2. Widget
+   1. Show how to list all Widget instances across all logical clusters
+   2. Get a Widget for the key from the queue, from the correct logical cluster
+   3. List all Widgets in the same logical cluster
+   4. Count the number of Widgets (list length)
+   5. Make sure `.status.total` matches the current count (via a `patch`)
+
+## Getting Started
+
+### Running on kcp
+
+1. Build and push your image to the location specified by `IMG`:
+
+```sh
+make docker-build docker-push IMG=<some-registry>/controller-runtime-example:tag
+```
+
+1. Deploy the controller to kcp with the image specified by `IMG`:
+
+```sh
+make deploy IMG=<some-registry>/controller-runtime-example:tag
+```
+
+### Uninstall resources
+To delete the resources from kcp:
+
+```sh
+make uninstall
+```
+
+### Undeploy controller
+Undeploy the controller from kcp:
+
+```sh
+make undeploy
+```
+
+## Contributing
+See [CONTRIBUTING.md](CONTRIBUTING.md)
+
+### How it works
+This project aims to follow the Kubernetes [Operator pattern](https://kubernetes.io/docs/concepts/extend-kubernetes/operator/)
+
+It uses [Controllers](https://kubernetes.io/docs/concepts/architecture/controller/) 
+which provides a reconcile function responsible for synchronizing resources until the desired state is reached. 
+
+### Test It Out
+1. Install the required resources into kcp:
+
+```sh
+make install
+```
+
+2. Run your controller (this will run in the foreground, so switch to a new terminal if you want to leave it running):
+
+```sh
+make run
+```
+
+**NOTE:** You can also run this in one step by running: `make install run`
+
+### Modifying the API definitions
+If you are editing the API definitions, regenerate the manifests using:
+
+```sh
+make manifests apiresourceschemas
+```
+
+**NOTE:** Run `make --help` for more information on all potential `make` targets
+
+More information can be found via the [Kubebuilder Documentation](https://book.kubebuilder.io/introduction.html)
+
+## License
+
+Copyright 2022.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+

api/v1alpha1/groupversion_info.go

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+/*
+Copyright 2022.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package v1alpha1 contains API Schema definitions for the data v1alpha1 API group
+//+kubebuilder:object:generate=true
+//+groupName=data.my.domain
+package v1alpha1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"sigs.k8s.io/controller-runtime/pkg/scheme"
+)
+
+var (
+	// GroupVersion is group version used to register these objects
+	GroupVersion = schema.GroupVersion{Group: "data.my.domain", Version: "v1alpha1"}
+
+	// SchemeBuilder is used to add go types to the GroupVersionKind scheme
+	SchemeBuilder = &scheme.Builder{GroupVersion: GroupVersion}
+
+	// AddToScheme adds the types in this group-version to the given scheme.
+	AddToScheme = SchemeBuilder.AddToScheme
+)

api/v1alpha1/widget_types.go

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+/*
+Copyright 2022.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// WidgetSpec defines the desired state of Widget
+type WidgetSpec struct {
+	Foo string `json:"foo,omitempty"`
+}
+
+// WidgetStatus defines the observed state of Widget
+type WidgetStatus struct {
+	Total int `json:"total,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+// +kubebuilder:subresource:status
+
+// Widget is the Schema for the widgets API
+type Widget struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   WidgetSpec   `json:"spec,omitempty"`
+	Status WidgetStatus `json:"status,omitempty"`
+}
+
+// +kubebuilder:object:root=true
+
+// WidgetList contains a list of Widget
+type WidgetList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []Widget `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&Widget{}, &WidgetList{})
+}