demo

README

Demo application

A demo K8s controller that listens for the custom resources based on the following CRD. Based on https://itnext.io/how-to-generate-client-codes-for-kubernetes-custom-resource-definitions-crd-b4b9907769ba and https://github.com/kubernetes/sample-controller

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: hellotypes.foo.com
spec:
  group: foo.com
  scope: Namespaced
  versions:
  - name: v1
    served: true
    storage: true
    schema:
      openAPIV3Schema:
        type: object
        properties:
          spec:
            type: object
            properties:
              message:
                type: string
          status:
            type: object
            properties:
              availableReplicas:
                type: integer
    subresources:
      status: {}
    additionalPrinterColumns:
    - name: Replicas
      type: string
      jsonPath: .status.availableReplicas
  names:
    kind: HelloType
    shortNames:
    - ht
    plural: hellotypes
    singular: hellotype

To generate your own code

1. Install the following tools to your GOBIN directory.

     $ go install k8s.io/code-generator/cmd/client-gen@latest
     $ go install k8s.io/code-generator/cmd/applyconfiguration-gen@latest
     $ go install k8s.io/code-generator/cmd/conversion-gen@latest
     $ go install k8s.io/code-generator/cmd/deepcopy-gen@latest
     $ go install k8s.io/code-generator/cmd/defaulter-gen@latest
     $ go install k8s.io/code-generator/cmd/go-to-protobuf@latest
     $ go install k8s.io/code-generator/cmd/informer-gen@latest
     $ go install k8s.io/code-generator/cmd/prerelease-lifecycle-gen@latest
     $ go install k8s.io/code-generator/cmd/register-gen@latest
   

2. Clone the kubernetes code-generator repository
   1. cd ~
   2. mkdir -p go/src/k8s.io
   3. cd go/src/k8s.io
   4. git clone https://github.com/kubernetes/code-generator.git
   5. cd code-generator
   6. git checkout v0.29.2
3. Follow this guide to create the superman/demo repo with the golang code in the appropriate files:
   1. pkg/apis/foo/v1/doc.go
   2. pkg/apis/foo/v1/register.go
   3. pkg/apis/foo/v1/types.go
4. In your demo repo
   1. go mod init
   2. git init
   3. git add .
   4. git commit -m "check in all demo files"
5. Run the following to generate the k8s required code:

     /go/src/k8s.io/code-generator/generate-groups.sh all "github.com/superman/demo/pkg/client" "github.com/superman/demo/pkg/apis" foo:v1 --go-header-file ~/go/src/k8s.io/code-generator/examples/hack/boilerplate.go.txt
   

6. Copy the generated code that was generated to github.com/ inside of your repo to the top level demo folder
   1. cp -R github.com/jacob-delgado/demo/pkg .
   2. rm -rf github.com
7. go mod tidy
8. git add .
9. git commit -m "check in generated files"

Running this repository

1. Install Skaffold.
2. Install kind
3. From your command line

     $ skaffold dev