Kubernetes - Deployment

Topics

1. Create Deployment
2. Scale the Deployment
3. Expose Deployment as a Service
4. Update Deployment
5. Rollback Deployment
6. Rolling Restarts
7. Pause & Resume Deployments
8. Canary Deployments (Will be covered at Declarative section of Deployments)

Step-01: Introduction to Deployments

• What is a Deployment?
• What all we can do using Deployment?
• Create a Deployment
• Scale the Deployment
• Expose the Deployment as a Service

Step-02: Create Deployment

• Create Deployment to rollout a ReplicaSet
• Verify Deployment, ReplicaSet & Pods
• Docker Image Location: https://hub.docker.com/repository/docker/stacksimplify/kubenginx

  # Create Deployment
  kubectl create deployment <Deplyment-Name> --image=<Container-Image>
  kubectl create deployment my-first-deployment --image=stacksimplify/kubenginx:1.0.0 
  
  # Verify Deployment
  kubectl get deployments
  kubectl get deploy 
  
  # Describe Deployment
  kubectl describe deployment <deployment-name>
  kubectl describe deployment my-first-deployment
  
  # Verify ReplicaSet
  kubectl get rs
  
  # Verify Pod
  kubectl get po
  

Step-03: Scaling a Deployment

• Scale the deployment to increase the number of replicas (pods)

  # Scale Up the Deployment
  kubectl scale --replicas=20 deployment/<Deployment-Name>
  kubectl scale --replicas=20 deployment/my-first-deployment 
  
  # Verify Deployment
  kubectl get deploy
  
  # Verify ReplicaSet
  kubectl get rs
  
  # Verify Pods
  kubectl get po
  
  # Scale Down the Deployment
  kubectl scale --replicas=10 deployment/my-first-deployment 
  kubectl get deploy
  

AWS EKS - Elastic Kubernetes Service - Masterclass

Step-04: Expose Deployment as a Service

• Expose Deployment with a service (NodePort Service) to access the application externally (from internet)

  # Expose Deployment as a Service
  kubectl expose deployment <Deployment-Name>  --type=NodePort --port=80 --target-port=80 --name=<Service-Name-To-Be-Created>
  kubectl expose deployment my-first-deployment --type=NodePort --port=80 --target-port=80 --name=my-first-deployment-service
  
  # Get Service Info
  kubectl get svc
  Observation: Make a note of port which starts with 3 (Example: 80:3xxxx/TCP). Capture the port 3xxxx and use it in application URL below. 
  
  # Get Public IP of Worker Nodes
  kubectl get nodes -o wide
  Observation: Make a note of "EXTERNAL-IP" if your Kubernetes cluster is setup on AWS EKS.
  

• Access the Application using Public IP

  http://<worker-node-public-ip>:<Node-Port>