Scaling and changing deployments¶

We are going to open up the client-deployment.yaml file:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: client-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      component: web
  template:
    metadata:
      labels:
        component: web
    spec:
      containers:
        - name: client
          image: deiveris/multi-client
          ports:
            - containerPort: 3000

And modify the port that previously failed on pod update:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: client-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      component: web
  template:
    metadata:
      labels:
        component: web
    spec:
      containers:
        - name: client
          image: deiveris/multi-client
          ports:
            - containerPort: 9999

$ kubectl apply -f client-deployment.yaml 
deployment.apps/client-deployment configured
$ kubectl get pods
NAME                                 READY   STATUS    RESTARTS   AGE
client-deployment-69f476d99b-s4trm   1/1     Running   0          18s
$ kubectl get deployments 
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
client-deployment   1/1     1            1           10m

$ kubectl describe pods 

Name:               client-deployment-69f476d99b-s4trm
Namespace:          default
Priority:           0
PriorityClassName:  <none>
Node:               minikube/10.0.2.15
Start Time:         Sun, 17 Mar 2019 17:08:31 +0200
Labels:             component=web
                    pod-template-hash=69f476d99b
Annotations:        <none>
Status:             Running
IP:                 172.17.0.5
Controlled By:      ReplicaSet/client-deployment-69f476d99b
Containers:
  client:
    Container ID:   docker://7c59d43a6cd56c8eabfca5230f1fe2929b52debf49b58ff7d0022c6e8031ac93
    Image:          deiveris/multi-client
    Image ID:       docker-pullable://deiveris/multi-client@sha256:51c71c0006401fcb25f15b0bf809b58e0f5a3885271b3d655fe1ed685a2f64f9
    Port:           9999/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Sun, 17 Mar 2019 17:08:34 +0200
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-vq8qh (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-vq8qh:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-vq8qh
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  85s   default-scheduler  Successfully assigned default/client-deployment-69f476d99b-s4trm to minikube
  Normal  Pulling    84s   kubelet, minikube  pulling image "deiveris/multi-client"
  Normal  Pulled     83s   kubelet, minikube  Successfully pulled image "deiveris/multi-client"
  Normal  Created    83s   kubelet, minikube  Created container
  Normal  Started    82s   kubelet, minikube  Started container

We can see that the pod is working on the port 9999.

If we change the replicas: 5

$ kubectl get deployments
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
client-deployment   5/5     5            5           13m
$ kubectl get pods
NAME                                 READY   STATUS    RESTARTS   AGE
client-deployment-69f476d99b-9dzd5   1/1     Running   0          25s
client-deployment-69f476d99b-ct94h   1/1     Running   0          25s
client-deployment-69f476d99b-lwbcj   1/1     Running   0          25s
client-deployment-69f476d99b-nt5mz   1/1     Running   0          25s
client-deployment-69f476d99b-s4trm   1/1     Running   0          3m7s