/global-azure-kubernetes-dev

Índice

Primeros comandos

## set alias en powershell
Set-Alias -name k -value kubectl
k version
k cluster-info
k get all

dashboard

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0/aio/deploy/recommended.yaml
k describe secret -n kube-system
k proxy

Ir a: http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/

Pods

Crear un Pods

imperativo

kubectl run my-nginx --image=nginx:latest
kubectl get pods
kubectl get all
kubectl port-forward my-nginx 8080:80
kubectl describe pod my-nginx
kubectl delete pod my-nginx
kubectl get pods

Pods con YAML

apiVersion: v1
kind: Pod
metadata:
 name: my-nginx
spec:
 containers:
  - name: my-nginx
    image: nginx:alpine
kubectl apply -f .\nginx.pod.yml
kubectl delete -f .\nginx.pod.yml

Pod Probe

apiVersion: v1
kind: Pod
metadata:
 name: my-nginx
 labels:
  app: nginx
  rel: stable
spec:
 containers:
  - name: my-nginx
    image: nginx:alpine
    ports:
     - containerPort: 80
    resources:
    livenessProbe:
     httpGet:
      path: /index.html
      port: 80
     initialDelaySeconds: 15
     timeoutSeconds: 2
     periodSeconds: 5
     failureThreshold: 1
    readinessProbe:
     httpGet:
      path: /index.html
      port: 80
     initialDelaySeconds: 15
     periodSeconds: 5
     failureThreshold: 1
kubectl get pods --watch
kubectl exec my-nginx -it -- sh
´´´

´´´ sh
cd usr/share/nginx/html
rm index.html

Deployments

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
  labels:
    app: my-nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: my-nginx
  template:
    metadata:
      labels:
        app: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx:alpine
        ports:
        - containerPort: 80
        resources:
kubectl apply -f .\deployments\nginx.deployment.yml
kubectl get all
kubectl describe deployment my-nginx
delete pod
kubectl get all

Escalado

kubectl scale -f .\deployments\nginx.deployment.yml --replicas=4
kubectl get pods -w
kubectl delete pod [podname]
kubectl delete deployment my-nginx

Update

kubectl apply -f .\nginx.deployment.yml
kubectl get pods --watch
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
  labels:
    app: my-nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: my-nginx
  template:
    metadata:
      labels:
        app: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx:latest
        ports:
        - containerPort: 80
        resources:
          limits:
            memory: "128Mi" #128 MB
            cpu: "200m" #200 millicpu (.2 cpu or 20% of the cpu)
        readinessProbe:
          httpGet:
            path: /index.html
            port: 80
          initialDelaySeconds: 15
          periodSeconds: 5
          failureThreshold: 1
        livenessProbe:
          httpGet:
            path: /index.html
            port: 80
          initialDelaySeconds: 15
          timeoutSeconds: 2
          periodSeconds: 5
          failureThreshold: 1
kubectl apply -f .\nginx.deployment.yml

Services

Port forwarding

kubectl port-forward pod/name 8080:80
kubectl port-forward deployment/name 8080
kubectl port-forward service/name 8080
kubectl apply -f ./deployments/nginx.deployment.yml
kubectl get all

clusterIP

k exec pod/my-nginx-5bb9b897c8-mrgds -- curl -s http://10.1.0.106 
## clusterip address
k exec pod/my-nginx-5bb9b897c8-mrgds -- curl -s http://10.1.0.106 
apiVersion: v1
kind: Service

metadata:
  type: ClusterIP
  name: nginx-clusterip ## DNS name (cluster internal)
  labels:
    app: nginx
spect:
  selector:
    app: nginx
  ports:
  - name: http
    port: 8080
    targetPort: 80
## clusterip DNS
k exec pod/my-nginx-5bb9b897c8-mrgds -- curl -s http://nginx-clusterip:8080

NodePort

apiVersion: v1
kind: Service
metadata:
 name: nginx-nodeport
spec:
  type: NodePort
  selector:
    app: my-nginx
  ports:
  - port: 80
    targetPort: 80
    nodePort: 31000

Loadbalancer

apiVersion: v1
kind: Service
metadata:
 name: nginx-loadbalancer
spec:
 type: LoadBalancer
 selector:
    app: my-nginx
 ports:
  - name: "80"
    port: 8080
    targetPort: 80
    
  # - name: "443"
  #   port: 443
  #   targetPort: 443
kubectl apply -f .\nginx.loadbalancer.yml
kubectl get all -o wide

Storage

persistent volume

apiVersion: v1
kind: PersistentVolume
metadata:
  name: task-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"
    type: DirectoryOrCreate #por defecto es Directory, en caso del directorio no existir daría error
kubectl apply -f .\pv.yml
kubectl get pv

Persistent volume claim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: task-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
kubectl apply -f .\pvc.yml
kubectl get pvc -o wide
kubectl get pv -o wide
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-nginx
  labels:
    app: my-nginx #importante para relacionar objetos
spec:
  replicas: 2
  selector:
    matchLabels:
      app: my-nginx #objetos a los que afecta
  template:
    metadata:
      labels:
        app: my-nginx #etiqueta custom para asociar este objeto
    spec: # definición de los Pods
      containers:
      - name: my-nginx
        image: nginx:alpine
        ports:
        resources: # acá pueden ir cosas como límites de CPU y memoria
        volumeMounts:
        - name: vol1
          mountPath: /usr/share/nginx/html        
      volumes:
      - name: vol1
        persistentVolumeClaim:
          claimName: task-pv-claim

configmap

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-configmap
spec:
  selector:
    matchLabels:
      app: nginx-configmap
  template:
    metadata:
      labels:
        app: nginx-configmap
    spec:
      containers:
      - name: nginx-configmap
        image: nginx:latest
        imagePullPolicy: IfNotPresent
        resources:
        ports:
        - containerPort: 9000

        volumeMounts: # montamos el config map como un volumen para tenerlo accesible en un directorio del container
          - name: app-config-vol
            mountPath: /etc/config

        env: # leemos cada environment variable de a una desde un config map creado
        - name: MY_ENV1
          valueFrom:
            configMapKeyRef:
              name: app-settings
              key: MY_KEY1
              optional: true

        envFrom: # leemos todas las environment variables y las cargamos en el container
        - configMapRef:
            name: app-settings

      volumes: # se crea un volumen a partir de un config map
      - name: app-config-vol
        configMap:
          name: app-settings

secrets

apiVersion: v1
kind: Pod
metadata:
  name: secret-env-pod
spec:
  containers:
  - name: mycontainer
    image: nginx
    env:
      - name: SECRET_USERNAME
        valueFrom:
          secretKeyRef:
            name: db-passwords
            key: db-username
      - name: SECRET_PASSWORD
        valueFrom:
          secretKeyRef:
            name: db-passwords
            key: db-password
  restartPolicy: Never