lab-3-answer-key.md

Lab 3 - Deploying and operating

Overview

In this lab, we will build a Docker image and deploy it to the microk8s cluster.

Procedure

Step 1 - Build Docker container image

1. Log into the microk8s VM with

vagrant ssh workshop_microk8s

2. Clone your fork of the Link app in the home directory:

git clone https://github.com/base10/link.git

3. Change into the Link directory with cd link and build the Docker image:

sudo docker build -t link-container . -f deploy/Dockerfile

4. Save the image to a tar file:

sudo docker save link-container:latest > ~/link-container.tar

5. Import the image in microk8s:

microk8s ctr image import ~/link-container.tar

Step 2 - Apply k8s yaml files

Run this command to apply the yaml files:

kubectl apply -f deploy/k8s

Step 3 - Review the app is running

1. Examine microk8s resources:

kubectl get all --all-namespaces

In the output from this command, you should see a pod, a deployment, a service, and a replicaset for link-app.

2. Visit http://172.16.100.10:30000/ and http://172.16.100.10:30000/sidekiq

Step 4 - Scale up and down

1. Run this command to scale the deployment up to 2 pods:

kubectl scale --replicas=2 deployment.apps/link-app

2. Run kubectl get all --all-namespaces to confirm that there are now two pods for the link-app deployment.

3. Run this command to scale back down:

kubectl scale --replicas=1 deployment.apps/link-app

4. Run kubectl get all --all-namespaces again to confirm that the cluster scaled back down to a single pod for link-app.