What’s in a basic project?

When scaffolding out a new project, Kubebuilder provides us with a fewbasic pieces of boilerplate.

Build Infrastructure

First up, basic infrastructure for building your project:

go.mod: A new Go module matching our project, with basic dependencies 
  1. module tutorial.kubebuilder.io/project
  3. go 1.12
  5. require (
  6.     github.com/go-logr/logr v0.1.0
  7.     github.com/gogo/protobuf v1.2.1 // indirect
  8.     github.com/json-iterator/go v1.1.6 // indirect
  9.     github.com/modern-go/reflect2 v1.0.1 // indirect
  10.     github.com/onsi/ginkgo v1.8.0 // indirect
  11.     github.com/onsi/gomega v1.5.0 // indirect
  12.     github.com/robfig/cron v1.1.0
  13.     github.com/spf13/pflag v1.0.3 // indirect
  14.     golang.org/x/net v0.0.0-20190501004415-9ce7a6920f09 // indirect
  15.     golang.org/x/sys v0.0.0-20190429190828-d89cdac9e872 // indirect
  16.     golang.org/x/text v0.3.2 // indirect
  17.     gopkg.in/yaml.v2 v2.2.2 // indirect
  18.     k8s.io/api v0.0.0-20190409021203-6e4e0e4f393b
  19.     k8s.io/apimachinery v0.0.0-20190404173353-6a84e37a896d
  20.     k8s.io/client-go v11.0.1-0.20190409021438-1a26190bd76a+incompatible
  21.     sigs.k8s.io/controller-runtime v0.2.0-beta.4
  22. )
Makefile: Make targets for building and deploying your controller 
  2. # Image URL to use all building/pushing image targets
  3. IMG ?= controller:latest
  4. # Produce CRDs that work back to Kubernetes 1.11 (no version conversion)
  5. CRD_OPTIONS ?= "crd:trivialVersions=true"
  7. all: manager
  9. # Run tests
  10. test: generate fmt vet manifests
  11.     go test ./api/… ./controllers/… -coverprofile cover.out
  13. # Build manager binary
  14. manager: generate fmt vet
  15.     go build -o bin/manager main.go
  17. # Run against the configured Kubernetes cluster in ~/.kube/config
  18. run: generate fmt vet
  19.     go run ./main.go
  21. # Install CRDs into a cluster
  22. install: manifests
  23.     kubectl apply -f config/crd/bases
  25. # Deploy controller in the configured Kubernetes cluster in ~/.kube/config
  26. deploy: manifests
  27.     kubectl apply -f config/crd/bases
  28.     kustomize build config/default | kubectl apply -f -
  30. # Generate manifests e.g. CRD, RBAC etc.
  31. manifests: controller-gen
  32.     $(CONTROLLER_GEN) $(CRD_OPTIONS) rbac:roleName=manager-role webhook paths="./api/…;./controllers/…" output:crd:artifacts:config=config/crd/bases
  34. # Run go fmt against code
  35. fmt:
  36.     go fmt ./…
  38. # Run go vet against code
  39. vet:
  40.     go vet ./…
  42. # Generate code
  43. generate: controller-gen
  44.     $(CONTROLLER_GEN) object:headerFile=./hack/boilerplate.go.txt paths=./api/…
  46. # Build the docker image
  47. docker-build: test
  48.     docker build . -t ${IMG}
  49.     @echo "updating kustomize image patch file for manager resource"
  50.     sed -i'' -e 's@image: .*@image: '"${IMG}"'@' ./config/default/manager_image_patch.yaml
  52. # Push the docker image
  53. docker-push:
  54.     docker push ${IMG}
  56. # find or download controller-gen
  57. # download controller-gen if necessary
  58. controller-gen:
  59. ifeq (, $(shell which controller-gen))
  60.     go get sigs.k8s.io/controller-tools/cmd/controller-gen@v0.2.0-beta.3
  61. CONTROLLER_GEN=$(shell go env GOPATH)/bin/controller-gen
  62. else
  63. CONTROLLER_GEN=$(shell which controller-gen)
  64. endif
PROJECT: Kubebuilder metadata for scaffolding new components 
  1. version: "2"
  2. domain: tutorial.kubebuilder.io
  3. repo: tutorial.kubebuilder.io/project

Launch Configuration

We also get launch configurations under theconfig/directory. Right now, it just containsKustomize YAML definitions required tolaunch our controller on a cluster, but once we get started writing ourcontroller, it’ll also hold our CustomResourceDefinitions, RBACconfiguration, and WebhookConfigurations.

config/default contains a Kustomize base for launchingthe controller in a standard configuration.

Each other directory contains a different piece of configuration,refactored out into its own base:

  • config/manager: launch your controllers as pods in thecluster

  • config/rbac: permissions required to run yourcontrollers under their own service account

The Entrypoint

Last, but certainly not least, Kubebuilder scaffolds out the basicentrypoint of our project: main.go. Let’s take a look at that next…