kindとは
Kubernetes in Dockerの略でDockerコンテナを複数個起動し、そのコンテナをKubernetesNodeとして利用することで、複数台構成のKubernetesクラスタを構築する。
作成する環境
以下の環境（Master1台、Worker1台のKubernetesClusterを1台)を作成する。
※VPS契約しなくてもMacやWindowsのローカルでできると思われます。
使用した環境のバージョン纏め
[root@xxxxxxxx ~]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
[root@xxxxxxxx ~]# docker version
Client: Docker Engine - Community
Version: 20.10.1
API version: 1.41
Go version: go1.13.15
Git commit: 831ebea
Built: Tue Dec 15 04:37:17 2020
OS/Arch: linux/amd64
Context: default
Experimental: true
Server: Docker Engine - Community
Engine:
Version: 20.10.1
API version: 1.41 (minimum version 1.12)
Go version: go1.13.15
Git commit: f001486
Built: Tue Dec 15 04:35:42 2020
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.4.3
GitCommit: 269548fa27e0089a8b8278fc4fc781d7f65a939b
runc:
Version: 1.0.0-rc92
GitCommit: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
docker-init:
Version: 0.19.0
GitCommit: de40ad0
[root@xxxxxxxx ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.0", GitCommit:"70132b0f130acc0bed193d9ba59dd186f0e634cf", GitTreeState:"clean", BuildDate:"2019-12-07T21:20:10Z", GoVersion:"go1.13.4", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.2", GitCommit:"52c56ce7a8272c798dbc29846288d7cd9fbae032", GitTreeState:"clean", BuildDate:"2020-06-03T04:00:21Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
[root@xxxxxxxx ~]# kind version
kind v0.7.0 go1.13.6 linux/amd64
1.初期設定、インストール
1−1. VPS初期設定（セキュリティ上の理由等で必要であれば）
・ユーザ作成
・sshd周りの設定（rootログイン禁止等）
・証明書配置
etc...
1−2. Docker インストール
(※参考URL)[https://qiita.com/ymasaoka/items/b6c3ffea060bcd237478]
1−3. kubectl のインストール [※参考URL]（https://tech-lab.sios.jp/archives/19226)
chmod +x ./kubectl
mv ./kubectl /usr/local/bin/
ls -l /usr/local/bin/kubectl
kubectl version
※以下エラー出るが無視
The connection to the server localhost:8080 was refused - did you specify the right host or port?
1−4. kind のインストール [※参考URL]（https://tech-lab.sios.jp/archives/19226)
curl -Lo ./kind "https://github.com/kubernetes-sigs/kind/releases/download/v0.7.0/kind-$(uname)-amd64"
chmod +x ./kind
mv ./kind /usr/local/bin/
ls -l /usr/local/bin/kind
kind version
2. 単一ノード (Master 1台構成)のkubernetesクラスタ作成
2−1. kubernetesクラスタ作成コマンド実行
[root@xxxxxxxx ~]# kind create cluster
Creating cluster "kind" ...
✓ Ensuring node image (kindest/node:v1.17.0) 🖼
✓ Preparing nodes 📦
✓ Writing configuration 📜
✓ Starting control-plane 🕹️
✓ Installing CNI 🔌
✓ Installing StorageClass 💾
Set kubectl context to "kind-kind"
You can now use your cluster with:
kubectl cluster-info --context kind-kind
Thanks for using kind! 😊
2−2. 確認
[root@xxxxxxxx ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
9cc673f1e968 kindest/node:v1.17.0 "/usr/local/bin/entr…" 2 minutes ago Up 2 minutes 127.0.0.1:49157->6443/tcp kind-control-plane
2−3.コンテキスト設定
※コンテキストを設定し指定することで、kubectlコマンドの対象のkubernetesクラスタを指定することができる
[root@xxxxxxxx ~]# kubectl cluster-info --context kind-kind
Kubernetes master is running at https://127.0.0.1:49157
KubeDNS is running at https://127.0.0.1:49157/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
2−4. kubernetesクラスタ起動確認
[root@xxxxxxxx ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
kind-control-plane Ready master 5m58s v1.17.0
2−5. kubernetesクラスタ削除
[root@xxxxxxxx ~]# kind delete cluster
Deleting cluster "kind" ...
[root@xxxxxxxx ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@xxxxxxxx ~]# kubectl get node
The connection to the server localhost:8080 was refused - did you specify the right host or port?
3. 複数ノード (Master 1台、Worker1台構成)のkubernetesクラスタ作成
3−1. yamlファイル作成
※apiVersion,imageのバージョンが合っていないと失敗する
kind.yaml
apiVersion: kind.x-k8s.io/v1alpha4
kind: Cluster
nodes:
- role: control-plane
image: kindest/node:v1.18.2
- role: worker
image: kindest/node:v1.18.2
3−2. kubernetesクラスタ作成コマンド実行
[root@xxxxxxxx ~]# kind create cluster --config kind.yaml --name kindclluster
Creating cluster "kindclluster" ...
✓ Ensuring node image (kindest/node:v1.18.2) 🖼
✓ Preparing nodes 📦 📦
✓ Writing configuration 📜
✓ Starting control-plane 🕹️
✓ Installing CNI 🔌
✓ Installing StorageClass 💾
✓ Joining worker nodes 🚜
Set kubectl context to "kind-kindclluster"
You can now use your cluster with:
kubectl cluster-info --context kind-kindclluster
Have a nice day! 👋
3−3. 確認
[root@xxxxxxxx ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
bc55874ac1ff kindest/node:v1.18.2 "/usr/local/bin/entr…" About a minute ago Up About a minute kindclluster-worker
57fd25bbbeba kindest/node:v1.18.2 "/usr/local/bin/entr…" About a minute ago Up About a minute 127.0.0.1:49158->6443/tcp kindclluster-control-plane
[root@xxxxxxxx ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
kindclluster-control-plane Ready master 72s v1.18.2
kindclluster-worker Ready <none> 37s v1.18.2
3−4. kubernetesクラスタ削除
[root@xxxxxxxx ~]# kind delete cluster
Deleting cluster "kind" ...
[root@xxxxxxxx ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@xxxxxxxx ~]# kubectl get node
The connection to the server localhost:8080 was refused - did you specify the right host or port?
4. nginxpodデプロイ
kubectl create deployment nginx --image=nginx
kubectl create service nodeport nginx --tcp=8080:80 service/nginx created
kubectl port-forward --address localhost svc/nginx 8080:8080
curl 127.0.0.1:8080
以上