TASK 96: Countdown job in Kubernetes

Requirements

The Nautilus DevOps team is working on to create few jobs in Kubernetes cluster. They might come up with some real scripts/commands to use, but for now they are preparing the templates and testing the jobs with dummy commands. Please create a job template as per details given below:

• Create a job countdown-nautilus.

• The spec template should be named as countdown-nautilus (under metadata), and the container should be named as container-countdown-nautilus

• Use image ubuntu with latest tag only and remember to mention tag i.e ubuntu:latest, and restart policy should be Never.

• Use command:

  for i in ten nine eight seven six five four three two one ; do echo $i ; done 

Note: The kubectl utility on jump_host has been configured to work with the kubernetes cluster.

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Note

This document focuses on the implementation approach. The task statement in Requirements is preserved as the source requirement.

Prerequisites

• Access to the configured Kubernetes cluster from jump_host.
• kubectl is configured and points to the correct context.
• Use the task-specified namespace, resource names, and images exactly.

Steps

As best practice, retrieve all resources first.

$ kubectl get all 

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   111m

Create the manifest for the resource definitions based on the requirements.

# countdown.yml
apiVersion: batch/v1
kind: Job
metadata:
  name: countdown-nautilus
spec:
  template:
    metadata:
      name: countdown-nautilus
    spec:
      containers:
        - name: container-countdown-nautilus
          image: ubuntu:latest
          command: ["/bin/sh", "-c"]
          args:
            [
              "for i in ten nine eight seven six five four three two one ; do echo $i ; done",
            ]
      restartPolicy: Never

Apply.

kubectl apply -f .

Verify by checking the resources again and checking the logs.

$ kubectl get pods
NAME                       READY   STATUS      RESTARTS   AGE
countdown-nautilus-9ffjb   0/1     Completed   0          21s 

$ kubectl get jobs
NAME                 COMPLETIONS   DURATION   AGE
countdown-nautilus   1/1           9s         39s 

$ kubectl logs -f countdown-nautilus-9ffjb
ten
nine
eight
seven
six
five
four
three
two
one 

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Verification

• Confirm the required pods/services/deployments/jobs are in the expected state.
• Run kubectl get commands for the affected resource types and namespace.

Resources