Solutions

Pod Creation

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  namespace: web
spec:
  containers:
    - name: nginx
      image: nginx

Pod Configuration

apiVersion: v1
kind: ConfigMap
metadata:
  name: yoda-service-config
data:
  yoda.cfg: |-
    yoda.baby.power=100000000
    yoda.strength=10

apiVersion: v1
kind: Secret
metadata:
  name: yoda-db-password
stringData:
  password: 0penSh1ftRul3s!

apiVersion: v1
kind: Pod
metadata:
  name: yoda-service
spec:
  serviceAccountName: yoda-svc
  containers:
  - name: yoda-service
    image: bitnami/nginx

Multiple Containers

apiVersion: v1
kind: ConfigMap
metadata:
  name: vader-service-ambassador-config
data:
  haproxy.cfg: |-
    global
        daemon
        maxconn 256

apiVersion: v1
kind: Pod
metadata:
  name: vader-service
spec:
  containers:
    - name: millennium-falcon
      image: ibmcase/millennium-falcon:1
    - name: haproxy-ambassador

apiVersion: v1
kind: Pod
metadata:
name: busybox
spec:
containers:
- name: myapp-container
    image: radial/busyboxplus:curl
    command: ['sh', '-c', 'while true; do sleep 3600; done']

Check it with

kubectl exec busybox -- curl $(kubectl get pod vader-service -o=jsonpath='{.status.podIP}'):80

Probes

apiVersion: v1
kind: Pod
metadata:
  name: energy-shield-service
spec:
  containers:
  - name: energy-shield
    image: ibmcase/energy-shield:1
    livenessProbe:

Debugging

Check STATUS column for not Ready

kubectl get pods --all-namespaces

Check the description of the deployment

kubectl describe deployment hyper-drive

Save logs for broken pod

kubectl logs <pod name> -n <namespace> > /home/cloud_user/debug/broken-pod-logs.log

In the deployment’s description you will see the following is wrong:

Selector and Label names do not match.
The Probe is TCP instead of HTTP Get.
The Service Port is 80 instead of 8080.

To fix probe, can't kubectl edit, need to delete and recreate the deployment

kubectl get deployment <deployment name> -n <namespace> -o yaml --export > hyper-drive.yml

Delete pod

kubectl delete deployment <deployment name> -n <namespace>

Edit yaml, and apply

kubectl apply -f hyper-drive.yml -n <namespace>

Verify

kubectl get deployment <deployment name> -n <namespace>

Rolling Updates

Update the deployment to the new version like so:

kubectl set image deployment/jedi-deployment jedi-ws=bitnamy/nginx:1.18.1 --record

Check the progress of the rolling update:

kubectl rollout status deployment/jedi-deployment

In another terminal window

kubectl get pods -w

Get a list of previous revisions.

kubectl rollout history deployment/jedi-deployment

Undo the last revision.

kubectl rollout undo deployment/jedi-deployment

Check the status of the rollout.

kubectl rollout status deployment/jedi-deployment

Cron Jobs

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: xwing-cronjob
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:

kubectl get cronjob xwing-cronjob

Services

apiVersion: v1
kind: Service
metadata:
    name: jedi-svc
spec:
    type: NodePort
    selector:
        app: jedi
    ports:

apiVersion: v1
kind: Service
metadata:
name: yoda-svc
spec:
type: ClusterIP
selector:
    app: yoda
ports:

Persistent Volumes

    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: postgresql-pv
    spec:
      storageClassName: localdisk
      capacity:
        storage: 1Gi
      accessModes:

    apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: postgresql-pv-claim
    spec:
      storageClassName: localdisk
      accessModes:
        - ReadWriteOnce
      resources:

    apiVersion: v1
    kind: Pod
    metadata:
      name: postgresql-pod
    spec:
      containers:
      - name: postgresql
        image: bitnami/postgresql
        ports:

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Kubernetes Lab Solutions

Solutions