CKA Tip 2: Imperative Command with kubectl

[Pod]

 

- Create an NGINX Pod

kubectl run nginx --image=nginx

 

- Generate POD Manifest YAML file (-o yaml). Don't create it(--dry-run)

kubectl run nginx --image=nginx --dry-run=client -o yaml

 

[Deployment]

 

- create a deployment

kubectl create deploymnet --iage=nginx nginx

 

- Generate Deployment YAML file (-o yaml). Don't create it (--dry-run)

kubectl create deployment --image=nginx nginx --dry-run -o yaml

 

- Generate Deployment with 4 Replicas

kubectl create deployment nginx --image=nginx --replicas=4

 

- Create a deployment with kubectl scale

kubectl scale deploymnet nginx --replicas=4

 

- Another way to do this to save the YAML definition to a file.

kubectl create deployment nginx --image=nginx --dry-run=client -o yaml > nginx-deployment.yaml

 

[Service]

 

- Create a Service named redis-service of the ClusterIP to expose pod redis on port 6379

kubectl expose pod redis --port=6379 --name redis-service --dry-run=client -o yaml

자동으로 selectors로서 Pod의 label 사용된다.

or

kubectl create service clusterip redis --tcp=6379:6379 --dry-run=client -o yaml

이것은 selector 로서 pod의 label이 사용되는것 대시 app=redis가 selector로서 사용된다. 옵션으로 selector를 사용할수 없다.

 

- Create a Service named nginx of type NodePort to expose pod nginx's port 80 on port 30080 on the nodes:

kubectl expose pod nginx --port=80 --name nginx-service --type=NodePort --dry-run=client -o yaml

위 명령으로는 nodeport를 지정할 수 없어 yaml 파일에서 수정해줘야 한다.

 

or

kubectl create service nodeport nginx --tcp=80:80 --node-port=30080 --dry-run=client -o yaml