TASK 127: Kubernetes Time Check Pod

Requirements

The Nautilus DevOps team want to create a time check pod in a particular Kubernetes namespace and record the logs. This might be initially used only for testing purposes, but later can be implemented in an existing cluster. Please find more details below about the task and perform it.

• Create a pod called time-check in the devops namespace.

• This pod should run a container called time-check, container should use the busybox image with latest tag only and remember to mention tag i.e busybox:latest.

• Create a config map called time-config with the data TIME_FREQ=2 in the same namespace.

• The time-check container should run the command below and should write the result to the location /opt/security/time/time-check.log.

  while true; do date; sleep $TIME_FREQ;done  

• Remember you will also need to add an environmental variable TIME_FREQ in the container, which should pick value from the config map TIME_FREQ key.

• Create a volume log-volume and mount the same on /opt/security/time within the container.

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

Begin by checking all the resources first.

thor@jump_host ~$ kubectl get namespace  
NAME                 STATUS   AGE
default              Active   169m
kube-node-lease      Active   169m
kube-public          Active   169m
kube-system          Active   169m
local-path-storage   Active   169m

thor@jump_host ~$ kubectl get all
NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   169m

Create the timechecker.yml file. This should contain the namespace and the pod definitions.

apiVersion: v1
kind: Namespace
metadata:
  name: devops 
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: time-config
  namespace: devops
data:
  TIME_FREQ: "2"
---
apiVersion: v1
kind: Pod
metadata:
  name: time-check
  namespace: devops
  labels:
    app: time-check
spec:
  volumes:
    - name: log-volume
      emptyDir: {}
  containers:
    - name: time-check
      image: busybox:latest
      volumeMounts:
        - mountPath: /opt/security/time
          name: log-volume
      envFrom:
        - configMapRef:
            name: time-config
      command: ["/bin/sh", "-c"]
      args:
        [
          "while true; do date; sleep $TIME_FREQ;done > /opt/security/time/time-check.log",
        ] 

Apply.

kubectl apply -f timechecker.yml

Check the pod.

thor@jump_host ~$ kubectl get pods -n devops
NAME         READY   STATUS    RESTARTS   AGE
time-check   1/1     Running   0          30s 

We can also check the file created inside the container.

thor@jump_host ~$ kubectl exec -n devops  -it time-check -- ls -lrt /opt/security/time
total 4
-rw-r--r--    1 root     root          1827 Jun  2 06:35 time-check.log 

thor@jump_host ~$ kubectl exec -n devops  -it time-check -- tail -10 /opt/security/time/time-check.log
Fri Jun  2 06:36:02 UTC 2023
Fri Jun  2 06:36:04 UTC 2023
Fri Jun  2 06:36:06 UTC 2023
Fri Jun  2 06:36:08 UTC 2023
Fri Jun  2 06:36:10 UTC 2023
Fri Jun  2 06:36:12 UTC 2023
Fri Jun  2 06:36:14 UTC 2023
Fri Jun  2 06:36:16 UTC 2023
Fri Jun  2 06:36:18 UTC 2023
Fri Jun  2 06:36:21 UTC 2023

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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