Starters

• A node may be a VM or physical machine, depending on the cluster.

• The scheduler distributes work or containers across multiple nodes.

• Have a good understanding of YAML files and when to use them:

  • List, dictionary, List of Dictionaries.

Pods

• • kubectl get pods -o wide

    • kubectl describe pods <POD_NAME>

    • kubectl delete pod <POD_NAME> --grace-period=0

    • kubectl get pod -o yaml

    • kubectl run redis --image=redis123 --dry-run=client -o yaml > redis.yaml

      

Replication Controller vs Replica Set

• • kubectl get replicaset

    • kubectl scale replicaset <REPLICASET_NAME> --replicas=2

    • kubectl delete replicaset <REPLICASET_NAME>

    • Check for apiVersion: kubectl api-resources | grep replicaset

    • kubectl scale replicaset new-replica-set --replicas=0

      

Deployments

• [Deploy, Upgrade, Rolling Updates, Rollback, Pause, Resume]

• Rollout and Versioning

• Recreate (Face downtime) vs RollingUpdate (Take down one by one)

• Summarize Commands

  • kubectl create –f <DEPLOYMENT_YAML_FILE>

  • kubectl get deployments

  • kubectl apply –f <DEPLOYMENT_YAML_FILE>

  • kubectl set image deployment/<DEPLOYMENT_NAME> <CONTAINER_NAME>=<NEW_IMAGE>

  • kubectl rollout status deployment/<DEPLOYMENT_NAME>

  • kubectl rollout history deployment/<DEPLOYMENT_NAME>

  • kubectl rollout undo deployment/<DEPLOYMENT_NAME>

• Networking in Kubernetes

Services

• • Enable connectivity between a group of pods and an external source

    • Node port (30000 to 32767), Cluster IP (Virtual IP), Load Balancer

    • NodePort:

      • minikube service myapp-svc --url

    • Cluster IP:

      • It is the default setting

    • 

    • Load Balancer:

      • Works as expected only with Cloud Providers like GCloud, AWS, Azure.

      • Otherwise act as Nodeport.

Microservices

• • 

P. S.

Credits: mumshad mannambeth

GitHub Repo