Go to Qiita Advent Calendar 2024 Top
LoginSignup
34
29

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?

More than 5 years have passed since last update.

エーピーコミュニケーションズAdvent Calendar 2018

Day 18
@cyberblack28(Yutaka Ichikawa)

WordPress環境を作る Kubernetes編

Last updated at Posted at 2018-12-17

RKE(Rancher Kubernetes Engine) を使用して、Kubernetesクラスタを構築して、WordPressをデプロイします。HostPathによるPV,PVCの作成、WordPressのPodを削除してセルフヒーリングされるか、replicas数を変更してスケールアウトできるかなど確認してみたいと思います。

図2.png

1.RKE(Rancher Kubernetes Engine) Serverの構築

1.Instance(rke-server)準備

項目 入力概要
名前 rke-server
リージョン asia-northeast1(東京)
ゾーン asia-northeast1-b
マシンタイプ vCPUx1
ブートディスク Ubuntu 16.04 LTS
ディスクサイズ80GB
ファイアウォール HTTP トラフィックを許可する、HTTPS トラフィックを許可するの両方をチェックします。

2.Kubernetes ClusterのNode用鍵ペア（公開鍵と秘密鍵）の作成

作成したインスタンスのLinuxサーバにログインして、以下のコマンドを実行します。
パスフレーズは何も入れず、Enterキーを押下します。

コマンド
$ ssh-keygen -t rsa -f ~/.ssh/id_rsa -C ubuntu
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:1oC/51l1s4p/KI9Nq5S4g/us8jmKok5rJw7F10ZuA78 root
The key's randomart image is:
+---[RSA 2048]----+
|                 |
|       .         |
|    . o .        |
| .   * . o       |
|  o . B S .   ...|
| . . o + .. .. .o|
|..    E o..o.... |
|o+.... oo+o+=.o. |
|*++. .+==+++=*.  |
+----[SHA256]-----+

3.秘密鍵のパーミッション変更

コマンド
$ chmod 600 .ssh/id_rsa

4.公開鍵の確認

コマンド
$ cat .ssh/id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCnt8H8BHO3+klKBaf8dR6X6wPsNbMZQe1Zp+BTMV34oNd724V9bhu3P0UV8JjzSdI6ocZCxX8kwaMOY+c9Km8PBjzYyEPUlXN2y4eJBGi48lq91ZRushpXr/xaUSu8cqEmxD3/fzBdN0T4PxK8A6l71zjPOkh1vklLcMiQzSV64VsrT6KvJcglEHSxgHK9A5EMGErkWNcXgKwGjnVn4k4j5SkK19EQ9A4tqKD79rfEvvcZCUGiiGsEu8HdfKNVxKeUXs53YjXs3MXeiW6XbjRbMvY/PRicT//rsGMwNVZOS7kvGvNOHWmmsw5gFNJ9UBLg2M7RUo+RUwKnnpsA/Lzr ubuntu

※公開鍵の内容を別途テキスト保存しておきましょう。
※こちらのものではなく各自の公開鍵を利用します。

2.k8s-clusterサーバの構築

1.Instance(k8s-cluster)準備

項目 入力概要
名前 k8s-cluster
リージョン asia-northeast1(東京)
ゾーン asia-northeast1-b
マシンタイプ vCPUx1
ブートディスク Ubuntu 16.04 LTS
ディスクサイズ80GB
ファイアウォール HTTP トラフィックを許可する、HTTPS トラフィックを許可するの両方をチェックします。

GCP(Google Cloud Platform)のGCE(Google Compute Engine)でインスタンスを作成する際に、公開鍵を登録できるので利用します。
※他のクラウドでも同じことができる場合は利用してください。こうした設定がない場合はサーバ起動後に公開鍵を登録してください。

image.png

2.rke-serverからk8s-clusterへリモート接続

コマンド
$ ssh -l ubuntu k8s-clusterサーバのグローバルIPアドレス
sts.
Welcome to Ubuntu 16.04.5 LTS (GNU/Linux 4.15.0-1025-gcp x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

  Get cloud support with Ubuntu Advantage Cloud Guest:
    http://www.ubuntu.com/business/services/cloud

0 packages can be updated.
0 updates are security updates.

New release '18.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.



The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.
ubuntu@k8s-cluster:~$

3.Dockerをインストール

コマンド
$ curl https://releases.rancher.com/install-docker/17.03.sh | sh
・
・省略
・
 Go version:   go1.7.5
 Git commit:   f5ec1e2
 Built:        Tue Jun 27 03:35:14 2017
 OS/Arch:      linux/amd64
Server:
 Version:      17.03.2-ce
 API version:  1.27 (minimum version 1.12)
 Go version:   go1.7.5
 Git commit:   f5ec1e2
 Built:        Tue Jun 27 03:35:14 2017
 OS/Arch:      linux/amd64
 Experimental: false
If you would like to use Docker as a non-root user, you should now consider
adding your user to the "docker" group with something like:
  sudo usermod -aG docker ubuntu
Remember that you will have to log out and back in for this to take effect!
WARNING: Adding a user to the "docker" group will grant the ability to run
         containers which can be used to obtain root privileges on the
         docker host.
         Refer to https://docs.docker.com/engine/security/security/#docker-
daemon-attack-surface
         for more information.

4.sudo無効化

コマンド
$ sudo usermod -aG docker ubuntu

5.リモートログインサーバからexitします。

コマンド
$ exit
logout
Connection to 104.198.89.202 closed.

3.RKE環境の構築

1.RKEのインストール

a.GitHubからRKEをダウンロード

コマンド
$ wget https://github.com/rancher/rke/releases/download/v0.1.13/rke_linux-amd64
256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20181208%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181208T133911Z&X-Amz-Expires=300&X-Amz-Signature=17ad3b2d3405c18337928d6294f22bb6026bfc6eb37399677ba843829246a6da&X-Amz-SignedHeaders=host&actor_id=0&response-content-disposition=attachment%3B%20filename%3Drke_linux-amd64&response-content-type=application%2Foctet-stream [following]
--2018-12-08 13:39:11--  https://github-production-release-asset-2e65be.s3.amazonaws.com/108337180/f04efa00-f806-11e8-8975-37ab922b79cb?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20181208%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181208T133911Z&X-Amz-Expires=300&X-Amz-Signature=17ad3b2d3405c18337928d6294f22bb6026bfc6eb37399677ba843829246a6da&X-Amz-SignedHeaders=host&actor_id=0&response-content-disposition=attachment%3B%20filename%3Drke_linux-amd64&response-content-type=application%2Foctet-stream
Resolving github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)... 52.216.169.211
Connecting to github-production-release-asset-2e65be.s3.amazonaws.com (github-production-release-asset-2e65be.s3.amazonaws.com)|52.216.169.211|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 32536526 (31M) [application/octet-stream]
Saving to: ‘rke_linux-amd64’

rke_linux-amd64    100%[===============>]  31.03M  11.8MB/s    in 2.6s    

2018-12-08 13:39:15 (11.8 MB/s) - ‘rke_linux-amd64’ saved [32536526/32536526]

b.rke_linux-amd64ファイルのリネーム

コマンド
$ mv rke_linux-amd64 rke

c.rkeファイルに実行権を付与

コマンド
# chmod +x rke

d.rkeコマンドの実行

コマンド
# ./rke
NAME:
   rke - Rancher Kubernetes Engine, an extremely simple, lightning fast Kubernetes installer that works everywhere

USAGE:
   rke [global options] command [command options] [arguments...]
   
VERSION:
   v0.1.13
   
AUTHOR(S):
   Rancher Labs, Inc. 
   
COMMANDS:
     up       Bring the cluster up
     remove   Teardown the cluster and clean cluster nodes
     version  Show cluster Kubernetes version
     config   Setup cluster configuration
     etcd     etcd snapshot save/restore operations in k8s cluster
     help, h  Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --debug, -d    Debug logging
   --help, -h     show help
   --version, -v  print the version

4.RKEでkubernetesクラスタの構築

1.cluster.ymlの作成

コマンド
# vim cluster.yml
----------------------------------------------------
nodes:
    - address: k8s-clusterのクローバルIPアドレス
      user: root
      role:
        - controlplane
        - etcd
        - worker
network:
    plugin: canal
ingress:
    provider: nginx
----------------------------------------------------
Esc + :wq

2.kubernetes clusterの構築

コマンド
# ./rke up
INFO[0000] Building Kubernetes cluster 
・
・省略
・ 
INFO[0153] Finished building Kubernetes cluster successfully

3.kubectl configの準備

コマンド
# mkdir .kube
# cp kube_config_cluster.yml ~/.kube/config

5.kubectlコマンドのインストール

1.kubectl(linux用)をダウンロード

コマンド
$ curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 54.6M  100 54.6M    0     0  38.9M      0  0:00:01  0:00:01 --:--:-- 38.9M

2.実行権限の付与

コマンド
$ chmod +x ./kubectl

3.kubectlファイルの移動

コマンド
$ sudo mv ./kubectl /usr/local/bin/kubectl

4.kubectlコマンドの実行

コマンド
$ kubectl version
Client Version: version.Info{Major:"1", Minor:"13", GitVersion:"v1.13.0", GitCommit:"ddf47ac13c1a9483ea035a79cd7c10005ff21a6d", GitTreeState:"clean", BuildDate:"2018-12-03T21:04:45Z", GoVersion:"go1.11.2", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"11", GitVersion:"v1.11.5", GitCommit:"753b2dbc622f5cc417845f0ff8a77f539a4213ea", GitTreeState:"clean", BuildDate:"2018-11-26T14:31:35Z", GoVersion:"go1.10.3", Compiler:"gc", Platform:"linux/amd64"}

5.kubernetes clusterのNode確認

コマンド
$ kubectl get nodes
NAME             STATUS   ROLES                      AGE   VERSION
104.198.89.202   Ready    controlplane,etcd,worker   8m    v1.11.5

6.WordPress on Kubernetes

1.MySQLのデプロイ

a.データベースのパスワードを格納する Kubernetes シークレットを作成

passwordには、任意のパスワードを指定します。

コマンド
# kubectl create secret generic mysql --from-literal=password=wordpress123@@@
secret/mysql created

b.「mysql-pv.yml」の作成

コマンド
# vim mysql-pv.yml
-----------------------------------------------------
apiVersion: v1
kind: PersistentVolume
metadata:
  name: mysql-pv
  labels:
    type: local
spec:
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Recycle
  hostPath:
    path: /tmp/data/mysql
-----------------------------------------------------
Esc + :wq

c.pvの作成

コマンド
# kubectl create -f mysql-pv.yml
persistentvolume/mysql-pv created

d.「mysql-pvc.yml」の作成

コマンド
# vim mysql-pvc.yml
-----------------------------------------------------
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pvc
  labels:
    app: wordpress
    tier: mysql
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
-----------------------------------------------------
Esc + :wq

e.pvcの作成

コマンド
# kubectl create -f mysql-pvc.yml
persistentvolumeclaim/mysql-pvc created

f.pvとpvcの確認

コマンド
# kubectl get pvc,pv
NAME                              STATUS   VOLUME     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
persistentvolumeclaim/mysql-pvc   Bound    mysql-pv   20Gi       RWO                           2m

NAME                        CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM               STORAGECLASS   REASON   AGE
persistentvolume/mysql-pv   20Gi       RWO            Recycle          Bound    default/mysql-pvc                           2m

g.「mysql.yml」の作成

コマンド
# vim mysql.yml
-----------------------------------------------------
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mysql
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
        - image: mysql:5.7
          name: mysql
          env:
            - name: MYSQL_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  name: mysql
                  key: password
          ports:
            - containerPort: 3306
              name: mysql
          volumeMounts:
            - name: mysql-local-storage
              mountPath: /var/lib/mysql
      volumes:
        - name: mysql-local-storage
          persistentVolumeClaim:
            claimName: mysql-pvc
-----------------------------------------------------
Esc + :wq

h.MySQLのdeploymentの作成

コマンド
# kubectl create -f mysql.yml
deployment.extensions/mysql created

i.podの確認

コマンド
# kubectl get pod -l app=mysql
NAME                     READY   STATUS    RESTARTS   AGE
mysql-7fb595fb84-dnn9w   1/1     Running   0          14s

j.「mysql-service.yml」の作成

コマンド
# vim mysql-service.yml
-----------------------------------------------------
apiVersion: v1
kind: Service
metadata:
  name: mysql
  labels:
    app: mysql
spec:
  type: ClusterIP
  ports:
    - port: 3306
  selector:
    app: mysql
-----------------------------------------------------
Esc + :wq

k.serviceの作成

コマンド
kubectl create -f mysql-service.yml
service/mysql created

l.serviceの確認

コマンド
# kubectl get service mysql
NAME    TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
mysql   ClusterIP   10.43.82.149   <none>        3306/TCP   47s

2.WordPressのデプロイ

a.「wordpress-pv.yml」の作成

コマンド
# vim wordpress-pv.yml
-----------------------------------------------------
apiVersion: v1
kind: PersistentVolume
metadata:
  name: wordpress-pv
  labels:
    type: local
spec:
  capacity:
    storage: 20Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Recycle
  hostPath:
    path: /tmp/data/wordpress
-----------------------------------------------------
Esc + :wq

b.pvの作成

コマンド
# kubectl create -f wordpress-pv.yml
persistentvolume/wordpress-pv created

c.「wordpress-pvc.yml」の作成

コマンド
# vim wordpress-pvc.yml
-----------------------------------------------------
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: wordpress-pvc
  labels:
    app: wordpress
    tier: wordpress
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 20Gi
-----------------------------------------------------
Esc + :wq

d.pvcの作成

コマンド
# kubectl create -f wordpress-pvc.yml
persistentvolumeclaim/wordpress-pvc created

e.pvとpvcの確認

コマンド
# kubectl get pvc,pv
NAME                                  STATUS   VOLUME         CAPACITY   ACCESS MODES   STORAGECLASS   AGE
persistentvolumeclaim/mysql-pvc       Bound    mysql-pv       20Gi       RWO                           12m
persistentvolumeclaim/wordpress-pvc   Bound    wordpress-pv   20Gi       RWO                           1m

NAME                            CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                   STORAGECLASS   REASON   AGE
persistentvolume/mysql-pv       20Gi       RWO            Recycle          Bound    default/mysql-pvc                               12m
persistentvolume/wordpress-pv   20Gi       RWO            Recycle          Bound    default/wordpress-pvc                           3m

f.「wordpress.yml」の作成

コマンド
# vim wordpress.yml
-----------------------------------------------------
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: wordpress
  labels:
    app: wordpress
spec:
  replicas: 1
  selector:
    matchLabels:
      app: wordpress
  template:
    metadata:
      labels:
        app: wordpress
    spec:
      containers:
        - image: wordpress
          name: wordpress
          env:
          - name: WORDPRESS_DB_HOST
            value: mysql:3306
          - name: WORDPRESS_DB_PASSWORD
            valueFrom:
              secretKeyRef:
                name: mysql
                key: password
          ports:
            - containerPort: 80
              name: wordpress
          volumeMounts:
            - name: wordpress-local-storage
              mountPath: /var/www/html
      volumes:
        - name: wordpress-local-storage
          persistentVolumeClaim:
            claimName: wordpress-pvc
-----------------------------------------------------
Esc + :wq

g.WordPressのdeploymentの作成

コマンド
# kubectl create -f wordpress.yml
deployment.extensions/wordpress created

h.podの確認

コマンド
# kubectl get pod -l app=wordpress
NAME                        READY   STATUS    RESTARTS   AGE
wordpress-f5db5bccc-42z6p   1/1     Running   0          41s

i.「wordpress-service.yml」の作成

コマンド
# vim wordpress-service.yml
-----------------------------------------------------
apiVersion: v1
kind: Service
metadata:
  labels:
    app: wordpress
  name: wordpress
spec:
  type: NodePort
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  selector:
    app: wordpress
-----------------------------------------------------
Esc + :wq

j.serviceの作成

コマンド
# kubectl create -f wordpress-service.yml
service/wordpress created

k.serviceの確認

コマンド
# kubectl get svc -l app=wordpress
NAME        TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
wordpress   LoadBalancer   10.43.102.184   <pending>     80:30983/TCP   2m

この後、ブラウザでアクセスする際に利用するNodePortは、80:の後のポート番号になります。

3.WordPressにアクセス

a.Kubernetes MasterIPの確認

コマンド
# kubectl cluster-info
Kubernetes master is running at https://133.223.1.160:6443
KubeDNS is running at https://133.223.1.160:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.

b.Chromeブラウザを起動してアクセス

image.png

4.Podの自動修復（セルフヒーリング）

a.WordPressのPod状況を確認

コマンド
# kubectl get pod
NAME                        READY   STATUS    RESTARTS   AGE
mysql-7fb595fb84-q4csx      1/1     Running   0          20m
wordpress-f5db5bccc-5hgc5   1/1     Running   0          19m

b.WordPressのPodを削除

コマンド
# kubectl delete pod -l app=wordpress
pod "wordpress-f5db5bccc-5hgc5" deleted

c.WordPressのPod名の確認

Pod削除前と名前が変わり、新たなPodが作られています。

コマンド
# kubectl get pod
NAME                        READY   STATUS    RESTARTS   AGE
mysql-7fb595fb84-q4csx      1/1     Running   0          23m
wordpress-f5db5bccc-ds8wk   1/1     Running   0          1m

5.Podのスケールアウト

a.WordPressのPodを10個増やす

コマンド
# kubectl scale deployment wordpress --replicas 10
deployment.extensions/wordpress scaled

b.WordPressのPod状況を確認

コマンド
# kubectl get pod
NAME                        READY   STATUS    RESTARTS   AGE
mysql-7fb595fb84-q4csx      1/1     Running   0          30m
wordpress-f5db5bccc-95pwv   1/1     Running   0          37s
wordpress-f5db5bccc-dr44d   1/1     Running   0          36s
wordpress-f5db5bccc-ds8wk   1/1     Running   0          7m
wordpress-f5db5bccc-dx8xs   1/1     Running   0          37s
wordpress-f5db5bccc-hfqpc   1/1     Running   0          37s
wordpress-f5db5bccc-jcz7t   1/1     Running   0          36s
wordpress-f5db5bccc-l5vq9   1/1     Running   0          36s
wordpress-f5db5bccc-lf24s   1/1     Running   0          36s
wordpress-f5db5bccc-pznkd   1/1     Running   0          36s
wordpress-f5db5bccc-qg6kk   1/1     Running   0          36s

「wordpress.yml」内のreplicasの数値を変更して、kubectl applyコマンドを実行しても同じ結果となります。

6.クリーンアップ

a.deploymentの削除

コマンド
# kubectl delete -f wordpress.yml
deployment.extensions "wordpress" deleted
# kubectl delete -f mysql.yml
deployment.extensions "mysql" deleted

b.serviceの削除

コマンド
# kubectl delete -f wordpress-service.yml
service "wordpress" deleted
# kubectl delete -f mysql-service.yml
service "mysql" deleted

d.pvcの削除

コマンド
# kubectl delete -f wordpress-pvc.yml
persistentvolumeclaim "wordpress-pvc" deleted
# kubectl delete -f mysql-pvc.yml
persistentvolumeclaim "mysql-pvc" deleted

f.pvの削除

コマンド
# kubectl delete -f wordpress-pv.yml
persistentvolume "wordpress-pv" deleted
# kubectl delete -f mysql-pv.yml
persistentvolume "mysql-pv" deleted

g.podの確認

コマンド
# kubectl get pod -l app=wordpress
No resources found.
# kubectl get pod -l app=mysql
No resources found.

h.serviceの確認

コマンド
# kubectl get svc -l app=wordpress
No resources found.
# kubectl get svc -l app=mysql
No resources found.

i.pv,pvcの確認

コマンド
# kubectl get pvc,pv
No resources found.

7.Documents

34
29
1

Register as a new user and use Qiita more conveniently

  1. You get articles that match your needs
  2. You can efficiently read back useful information
  3. You can use dark theme
What you can do with signing up
Sign upLogin
34
29

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?