shu-mutou / k8s-hands-on-with-kind

Kubernetes sandbox

Setup

1. Use official kind

• Run get-kind.sh [-i <kind version>] [-n <kindest/node version>]
  • Download specified version of kind and latest version of kubectl.
  • Then, copy them as kind-[version] and kubectl-[latest version] into tools directory.
  • Also, create symbolic links kind for specified version of kind and kubectl for kubectl-[latest version] into tools directory.
  • Furthermore, create config file for kind with specified version of kindest/node image, i.e. kubernetes version, as ./tmp/kind.yaml.
• Options:
  • Specify kind version and kindest/node version with hash from release site for kind
  • kind version
    • Default: v0.11.0
  • kindest/node version
    • Default: kindest/node:v1.21.1@sha256:fae9a58f17f18f06aeac9772ca8b5ac680ebbed985e266f711d936e91d113bad

1'. Use custom kind (optional)

• Clone kind source code with git clone https://github.com/kubernetes-sigs/kind.
• Change code and commit them into your specified branch.
• Run build-kind.sh [-s <source code directory>] [-b <branch>] [-n <kindest/node version>]
  • Build kind from source code.
  • Then, copy it as kind-[branch] into tools directory.
  • Also, create symbolic link kind for kind-[branch] into tools directory.
• Options
  • branch
    • Default: master
  • kind source directory
    • Default: ${GOPATH}/src/github.com/kubernetes-sigs/kind
  • kindest/node version
    • Specify applicable version of kindest/node for your kind branch with hash from release site for kind.
    • Default: kindest/node:v1.21.1@sha256:fae9a58f17f18f06aeac9772ca8b5ac680ebbed985e266f711d936e91d113bad

2. Use custom Kubernetes (optional)

NOTE: Kubernetes v1.21.0 or later needs docker buildx to build. And docker buildx needs docker ce v19.03 or later. In ubuntu 20.04, the version of docker is v19.03.x but not enabled buildx. If so, setup buildx as followings.

mkdir -p ${HOME}/.docker/cli-plugins
wget -nc -O ${HOME}/.docker/cli-plugins/docker-buildx https://github.com/docker/buildx/releases/download/v0.5.1/buildx-v0.5.1.linux-amd64`
chmod +x ${HOME}/.docker/cli-plugins/docker-buildx

Also, create ${HOME}/.docker/config.json add {"experimental": "enabled"} into it.

• Clone kubernetes source code with git clone https://github.com/kubernetes/kubernetes.
• Change code and commit them into your specified branch.
• Run build-node-image.sh [-s <source code directory>] [-b <branch>]
  • Build all of kubernetes components from kubernetes source code.
  • Then, build kubernetes container image for kind node as kindest/node:[branch] into local docker host.
  • Also, copy built kubectl to kubectl-[branch] in tools directory.
  • Furthermore, create symbolic link kubectl for kubectl-[branch] into tools directory.
• Options
  • branch
    • Default: master
  • kubernetes source directory
    • Default: ${GOPATH}/src/github.com/kubernetes/kubernetes

Run Kubernetes with kind

• Run ./run-kind.sh [-c <kind config file>] [-x]
  • Create kubernetes cluster with specified version of kind and kindest/node.
  • Also, create ./kubectl.sh as alias of symbolic link kubectl that run with kubeconfig for created cluster.
• Options:
  • kind config
    • Config for kind cluster.
    • Default: ./tmp/kind.yaml
  • x
    • Ignore deploying Kubernetes Dashboard
    • Default: deploying Kubernetes Dashboard

Exercise 1 - enough for common application developer

• Deploy nginx

  ./kubectl.sh create deployment nginx --image=nginx:1.15 --port=80
  

  Confirm with following:

  ./kubectl.sh get deploy,pod
  

• Expose nginx

  ./kubectl.sh expose deployment nginx --type=NodePort --port=80 -oyaml --dry-run=client > tmp/nginx.svc.yaml
  

  Add nodePort: 30001 under ports in tmp/nginx.svc.yaml, then run following:

  ./kubectl.sh apply -f tmp/nginx.svc.yaml
  

  Confirm with following:

  ./kubectl.sh get svc -owide
  

• Access nginx with browser http://localhost:30001
• Create PersistentVolume and PersistentVolumeClaim.

  mkdir -p volume/nginx
  ./kubectl.sh apply -f example/pv.yaml
  ./kubectl.sh apply -f example/pvc.yaml
  

  Confirm with following:

  ./kubectl.sh get pv,pvc
  

• Use PersistentVolumeClaim for web root directory in nginx deployment.

  ./kubectl.sh get deployment nginx -oyaml > tmp/nginx.deploy.yaml
  

  Add followings:

  .....
  spec:
    .....
    template:
      .....
      spec:
        .....
        containers:
          .....
          volumeMounts:
          - mountPath: "/usr/share/nginx/html"
            name: nginx-volume
        volumes:
        - name: nginx-volume
          persistentVolumeClaim:
            claimName: nginx-pvc
  .....
  

  Then run following:

  ./kubectl.sh apply -f tmp/nginx.deploy.yaml
  

  Confirm with following:

  ./kubectl.sh get pv,pvc,pod
  

• Add volume/nginx/index.html.

  echo "Hello!" > volume/nginx/index.html
  

  Then confirm http://localhost:30001 via browser.

Exercise 2 - required for CKAD

• Scheduling pods for Ingress controller. Confirm current labels attached in nodes.

  ./kubectl.sh get nodes --show-labels
  

  Set label into control-plane node for Ingress controller.

  ./kubectl.sh label nodes kind-cluster-control-plane ingress-ready='true'
  

  Note: ingress-ready='true' is used in the following manifest for ingress-nginx-controller. The pod for Ingress controller will be scheduled by this label. Confirm labels added in control-plane nodes.

  ./kubectl.sh get nodes kind-cluster-control-plane --show-labels
  

• Install Ingress NGINX Controller

  wget -nc -O tmp/ingress-nginx-controller.yaml https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/provider/kind/deploy.yaml
  

  And add nodePort: 30080 and nodePort: 30443 into ingress-nginx-controller Service. Then install it:

  ./kubectl.sh apply -f tmp/ingress-nginx-controller.yaml
  

• Create Ingress for nginx Service via nginx-ingress-controller and modify nginx Service. See example/nginx-ingress.yaml, create test/ directory for Ingress nginx-ingress, and create index.html file into it.

  mkdir -p volume/nginx/test
  echo "Here is /test/ via Ingress" > volume/nginx/test/index.html
  

  Then run following:

  ./kubectl.sh apply -f example/nginx-ingress.yaml
  

• Access nginx http://localhost:30080/test/ via Ingress.

TBD

• Rollout deployment
  • Update image
  • History
  • Restart
  • Undo

References for kind

• Configure file for kind
  • Configure directory for Persistent Volume
  • Configure port for NodePort
• Ingress NGINX
• LoadBalancer with metallb