Kubernetes - Deployment

Kubernetes Deployment - Topics¶

Create Deployment
Scale the Deployment
Expose Deployment as a Service
Update Deployment
Rollback Deployment
Rolling Restarts
Pause & Resume Deployments
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

Update Change-Cause for the Kubernetes Deployment - Rollout History¶

Observation: We have the rollout history, so we can switch back to older revisions using revision history available to us

# Verify Rollout History
kubectl rollout history deployment/my-first-deployment

# Update REVISION CHANGE-CAUSE for Kubernetes Deployment
kubectl annotate deployment/my-first-deployment kubernetes.io/change-cause="Deployment CREATE - App Version 1.0.0"

# Verify Rollout History
kubectl rollout history deployment/my-first-deployment

Step-03: Scaling a Deployment¶

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

# Scale Up the Deployment
kubectl scale --replicas=10 deployment/<Deployment-Name>
kubectl scale --replicas=10 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=2 deployment/my-first-deployment 
kubectl get deploy

Step-04: Expose Deployment as a Service¶

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

# Expose Deployment as a Service
kubectl expose deployment <Deployment-Name>  --type=LoadBalancer --port=80 --target-port=80 --name=<Service-Name-To-Be-Created>
kubectl expose deployment my-first-deployment --type=LoadBalancer --port=80 --target-port=80 --name=my-first-deployment-service

# Get Service Info
kubectl get svc

Access the Application using Public IP

# Access Application
http://<External-IP-from-get-service-output>
curl http://<External-IP-from-get-service-output>