KodeKloud Challenges: Kubernetes Challenge 4

Check KodeKloud’s Kubernetes Challenge #4!

Note - if you really must see the solutions directly, find them on my GitHub page; okbobm!

What’s the scenario? Build a highly available Redis Cluster based on the given architecture diagram.

What are the general requirements for this challenge?

1. Create service (i.e. redis-cluster-service)
2. Create persistent volumes x6 (i.e. redis01-resdis06)
3. Create sts (i.e redis-cluster)
4. Run script

Step 1: Create service (i.e. redis-cluster-service)

Requirements:

• Ports - service name ‘redis-cluster-service’, port name: ‘client’, port: ‘6379’
• Ports - service name ‘redis-cluster-service’, port name: ‘gossip’, port: ‘16379’
• Ports - service name ‘redis-cluster-service’, port name: ‘client’, targetPort: ‘6379’
• Ports - service name ‘redis-cluster-service’, port name: ‘gossip’, targetPort: ‘16379’

Solution:

• Create a yaml file for the redis-cluster-service
  • Apply from yaml
    • k apply -f vote-deployment.yaml
  • Check service was created successfully
    • k get svc

Step 2: Create persistent volumes x6 (i.e. redis01-resdis06)

Note - this step grouped for all 6 persistent volumes

Requirements:

• PersistentVolume - Name: redis01
• Access modes: ReadWriteOnce
• Size: 1Gi
• hostPath: /redis01, directory should be created on worker node

Solution:

• Create a yaml file for the pv-redis0x
  • Option 1 - create all pv’s from one file, quickly modifying values for each pv set in the file. This is the option I used for this challenge to quickly get through the challenge, also with the exam mentality of a “quick and dirty” solution.
    • Apply from yaml
      • k apply -f pv-redis0x.yaml
    • Check persistent volumes was created successfully
      • k get pv
  • Option 2 - the better option (and goal of devsecops) is to script and automate whenever possible see here for a good option to script the creation of the 6 pv files.

Step 3: Create sts (i.e.redis-cluster-service)

Requirements:

• StatefulSet - Name: redis-cluster
• Replicas: 6
• Pods status: Running (All 6 replicas)
• Image: redis:5.0.1-alpine, Label = app: redis-cluster
• container name: redis, command: [“/conf/update-node.sh”, “redis-server”, “/conf/redis.conf”]
• Env: name: ‘POD_IP’, valueFrom: ‘fieldRef’, fieldPath: ‘status.podIP’ (apiVersion: v1)
• Ports - name: ‘client’, containerPort: ‘6379’
• Ports - name: ‘gossip’, containerPort: ‘16379’
• Volume Mount - name: ‘conf’, mountPath: ‘/conf’, readOnly:’false’ (ConfigMap Mount)
• Volume Mount - name: ‘data’, mountPath: ‘/data’, readOnly:’false’ (volumeClaim)
• volumes - name: ‘conf’, Type: ‘ConfigMap’, ConfigMap Name: ‘redis-cluster-configmap’,
• Volumes - name: ‘conf’, ConfigMap Name: ‘redis-cluster-configmap’, defaultMode = ‘0755’
• volumeClaimTemplates - name: ‘data’
• volumeClaimTemplates - accessModes: ‘ReadWriteOnce’
• volumeClaimTemplates - Storage Request: ‘1Gi’

Solution:

• Create a yaml file for the redis-cluster-service
  • Apply from yaml
    • k apply -f redis-cluster-service.yaml
  • Check sts was created successfully
    • k get svs

Step 4: Run script

Requirements:

• Run command

Solution:

• kubectl exec -it redis-cluster-0 – redis-cli –cluster create –cluster-replicas 1 $(kubectl get pods -l app=redis-cluster -o jsonpath=’{range.items[*]}{.status.podIP}:6379 {end}’)
• Click yes for full setup

Finally - completed!

You should see everything in green as in the diagram below:

Future bonus points: write a script to complete all the scripts at once!