YAML Files

apiVersion: # 要用來建立物件的 k8s API 版本 
kind: # 要建立的物件
metadata: # 物件的其他資訊，如 name, labels...

spec: # 建立物件需要的訊息

# 可以看介紹
kubectl explain <k8s kind>

apiVersion: v1
kind: Pod
metadata:
  name: myapp-pod
  labels:
    app: myapp
    type: front-end
spec:
  containers:
  - name: nginx-container
    image: nginx

# 建立
kubectl create -f pod-definition.yaml
# list
kubectl get pods
kubectl get po

apiVersion: v1
kind: ReplicationController
metadata:
  name: myapp-rc
  labels:
    app: myapp
    type: front-end
spec:
  template: # 下面是放 POD 的 meta data 和 spec，注意縮排
    metadata:
      name: myapp-pod
      labels:
        app: myapp
        type: front-end
    spec:
      containers:
      - name: nginx-container
        image: nginx 
  replicas: 3

kubectl apply -f rc-definition.yaml
# 取得 replication controllers
kubectl get replicationcontroller

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: myapp-replicaset
  labels:
    app: myapp
    type: front-end
spec:
  template: # 下面是放 POD 的 meta data 和 spec，注意縮排
    metadata:
      name: myapp-pod
      labels:
        app: myapp
        type: front-end
    spec:
      containers:
        - name: nginx-container
          image: nginx
  replicas: 3
  selector:
    matchLabels:
      type: front-end

# 建立
kubectl create -f replicaset-definition.yaml
# 更新 replicas 數量可以怎麼做
kubectl replace -f replicaset-definition.yaml # 要事先更新好 yaml
# or
kubectl scale --replicas=<target number> -f replicaset-definition.yaml
# or
kubectl scale --replicas=<target number> replicaset <replicaset name>
# 取得 replica sets
kubectl get replicaset
kubectl get rs
# 刪除 replicaset (底下的 pods 也會一並刪除)
kubectl delete replicaset <replicaset name>
# 直接更改物件的值 (會開啟 vim)
kubectl edit replicaset <replicaset name>

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp-deployment
  labels:
    app: myapp
    type: front-end
spec:
  template: # 下面是放 POD 的 meta data 和 spec，注意縮排
    metadata:
      name: myapp-pod
      labels:
        app: myapp
        type: front-end
    spec:
      containers:
        - name: nginx-container
          image: nginx
  replicas: 3
  selector:
    matchLabels:
      type: front-end

# 建立
kubectl create -f deployment-definition.yaml
# list
kubectl get deployments
kubectl get deploy
# 因為 deployment 會自動建立 replicaset，所以可以順便看一下
kubectl get replicaset
kubectl get pods
# 列出全部項目
kubectl get all

apiVersion: v1
kind: Service
metadata:
  name: myapp-service
spec:
  type: NodePort
  ports:
    - targetPort: 80
      port: 80
      nodePort: 30008
  selector: # 這邊放的是對應的 pod 的 labels
    app: myapp
    type: front-end 

# create
kubectl create -f service-definition.yaml
# list
kubectl get services
kubectl get svc

apiVersion: v1
kind: Service
metadata:
  name: back-end
spec:
  type: ClusterIP
  ports:
    - targetPort: 80 # backend pod 的 port
      port: 80 # 要進這個 service 的 port
  selector: # 這邊放的是對應的 pod 的 labels
    app: myapp
    type: backend-end 

apiVersion: v1
kind: Service
metadata:
  name: myapp-service 
spec:
  type: LoadBalancer
  ports:
    - targetPort: 80 # backend pod 的 port
      port: 80 # 要進這個 service 的 port
      nodePort: 30008

apiVersion: v1
kind: Namespace
metadata:
  name: dev

# 建立 dev 的 namespace
kubectl create namespace dev

apiVersion: v1
kind: ResourceQuota
metadata:
  name: compute-quota
  namespace: dev
spec:
  hard:
    pods: "10"
    requests.cpu: "4"
    requests.memory: 5Gi
    limits.cpu: "10"
    limits.memory: 10Gi