ENIB S7-NSA 12_deployment - Container deployment

As each tutorial is independent, it is recommended that you create a separate directory on your workstation in which to save your work for this tutorial.
This will allow you to retrieve the state of your work on each tutorial you have completed.

Do not hesitate to use any external help available, including your favourite LLM, to obtain explanations.
Of course, the session supervisor is here to help in any case.

You are strongly encouraged to take notes during your observations so that you can review them before the quizzes.

{} Deployments and volumes

kubectl config view
~~> rien
cp .../gX-YY.kubeconfig ~/.kube/config
kubectl config view
~~> user gX-YY (with token)
    namespace gX-YY
    cluster https://kube.enib.fr:6443 (with CA certificate)

kubectl get persistentvolumeclaims
~~> storage

alpine.yaml
~~~~~~~~~~~
apiVersion: apps/v1
kind: Deployment
metadata:
  name: alpine-dpl
  namespace: g1-01-ns
spec:
  replicas: 1
  selector:
    matchLabels:
      app: alpine
  template:
    metadata:
      labels:
        app: alpine
    spec:
      terminationGracePeriodSeconds: 1
      containers:
      - name: alpine
        image: alpine
        command: ["/bin/sh", "-c", "while true ; do sleep 2 ; done"]
        volumeMounts:
        - mountPath: /mnt
          name: storage-mount
      volumes:
      - name: storage-mount
        persistentVolumeClaim:
          claimName: storage

kubectl apply -f alpine.yaml
kubectl get deployments
kubectl get pods
kubectl exec pod/alpine-dpl-79b767fcdc-5xzw2 -it -- sh
  df -h / /mnt
  echo 'File 1' >/root/file1.txt
  echo 'File 2' >/mnt/file2.txt
kubectl delete pod/alpine-dpl-79b767fcdc-5xzw2
kubectl get pods
~~> nouveau pod recréé
kubectl exec pod/alpine-dpl-6fd895c947-xswrf -it -- ls -la /root /mnt
~~> /root perdu, /mnt conservé

FIXME: BLABLA

{} Replicas and services


ajout à alpine.yaml
~~~~~~~~~~~~~~~~~~~
---
apiVersion: v1
kind: Service
metadata:
  name: alpine-svc
  namespace: g1-01-ns
spec:
  type: LoadBalancer
  selector: 
    app: alpine
  ports:
  - protocol: TCP
    port: 9101
    targetPort: 9101
kubectl apply -f alpine.yaml
kubectl get services
kubectl exec pod/alpine-dpl-6fd895c947-xswrf -it -- nc -lp 9101
ncat kube.enib.fr 9101

dans alpine.yaml, replicas: 2
kubectl apply -f alpine.yaml
kubectl get deployments
kubectl get pods
kubectl get services
kubectl exec alpine-depl-79b767fcdc-5xzw2 -it -- nc -lp 9988
kubectl exec alpine-depl-79b767fcdc-ffxtf -it -- nc -lp 9988
premier client ncat kube.enib.fr 9101 ~~> dialogue, garder connecté
second  client ncat kube.enib.fr 9101
  ~~> connection refused si même pod, ou dialogue avec le second pod
  ~~> le service répartit les connections sur les deux pods

kubectl delete deployments alpine-dpl
kubectl delete services alpine-svc

FIXME: BLABLA

{} Running a custom image

kubectl create secret generic demo-sec \
  --from-literal=APP_DB_USER=demo_user \
  --from-literal=APP_DB_PASS=demo_secret \
  --dry-run=client -o yaml | kubectl apply -f -
kubectl get secrets
kubectl describe secrets demo-sec

kubectl apply -f sh_db_demo.yaml
kubectl get configmaps
kubectl describe configmaps demo-cfg
kubectl get deployments
kubectl get services

FIXME: BLABLA