K8s-Services-2

App: ToDo List

Code from Kubernetes Webinar Series - Understanding Service Discovery

https://www.youtube.com/watch?v=NrzrpyMLWes

Narrative for this demo

1. BUILD: build image locally on your laptop: docker build . -t <DOCKER_HUB_USER>/todo-app (then push the image to registry)

2. DEPLOY: run app locally on your laptop: docker-compose up -d

3. DEPLOY: run app on K8s cluster: kubectl create -f

Build a Docker image from existing node.js source code and push it to Docker Hub. Replace DOCKER_HUB_USER with your Docker Hub username.

cd Build-Docker
docker build . -t <DOCKER_HUB_USER>/todo-app
docker login
docker push <DOCKER_HUB_USER>/todo-app

Launch the app

docker-compose up -d

Test the app

curl localhost:3000

Deploy the app to Kubernetes

cd ../Deploy-Kubernetes
kubectl create -f web-pod.yml
kubectl create -f web-service.yml
kubectl create -f db-pod.yml
kubectl create -f db-service.yml

Check that the Pods and Services are created

kubectl get pods
kubectl get svc

Test the app by accessing the NodePort of one of the nodes.

kubectl get nodes
curl <NODE_IP>:<NODE_PORT>

Useful links

ToDo app: http://dreamerslab.com/blog/en/write-a-todo-list-with-express-and-mongodb/

Source code page: https://github.com/dreamerslab/express-todo-example