====== 19 Kubernetes Scale ======

====== 1.nginx用意 ======
<code|my-nginx.yaml>
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
spec:
  selector:
    matchLabels:
      run: my-nginx
  replicas: 1
  template:
    metadata:
      labels:
        run: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx
        ports:
        - containerPort: 80
</code>

===== デプロイ =====

  kubectl create -f my-nginx.yaml

===== 確認 =====

<code>
# kubectl get deployments.apps my-nginx 
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
my-nginx   1/1     1            1           5m19s

# kubectl get pod -l run=my-nginx
NAME                       READY   STATUS    RESTARTS   AGE
my-nginx-cf54cdbf7-jd8xc   1/1     Running   0          2m23s
</code>

===== スケールを増やす =====

  kubectl scale deployment  my-nginx --replicas=3

==== 確認 ====

Podが3つに増えている

<code>
# kubectl get deployments.apps my-nginx 
NAME       READY   UP-TO-DATE   AVAILABLE   AGE
my-nginx   3/3     3            3           6m13s

# kubectl get pod -l run=my-nginx
NAME                       READY   STATUS    RESTARTS   AGE
my-nginx-cf54cdbf7-hgbdl   1/1     Running   0          27s
my-nginx-cf54cdbf7-j5lmk   1/1     Running   0          27s
my-nginx-cf54cdbf7-jd8xc   1/1     Running   0          6m32s
</code>


===== スケールを減らす =====

  kubectl scale deployment  my-nginx --replicas=1



==== 確認 ====

Podが1つに減っている

<code>
# kubectl get pod -l run=my-nginx
NAME                       READY   STATUS    RESTARTS   AGE
my-nginx-cf54cdbf7-jd8xc   1/1     Running   0          7m19s

# kubectl get pod -l run=my-nginx
NAME                       READY   STATUS    RESTARTS   AGE
my-nginx-cf54cdbf7-jd8xc   1/1     Running   0          7m39s
</code>

{{tag>Kubernetes Scale}}