# Javascript and Node (ExpressJS)

This example shows how to build, push, run a NodeJS based app in a Kontain container in Docker and Kubernetes.

implementation of this example

https://github.com/kontainapp/guide-examples/tree/master/examples/js/node-express-hello

# to build this example

$ docker build -t kontainguide/node-express-hello:1.0 .

# see image sizes for benefits of using Kontain base image

$ docker images | grep -E 'node'
...
node                               12      918MB
kontainguide/node-express-hello    1.0     84.2MB
kontainapp/runenv-node             latest  81.3MB
...

Please note that the image size for the Kontain based container is 84.2MB versus the base node image has a size of 918MB

# to run this example

$ docker run -d --rm -p 8080:8080 --runtime=krun --name node-express-hello kontainguide/node-express-hello:1.0

# invoke the service
$ curl -v http://localhost:8080

$ docker stop node-express-hello

# to run this example in docker-compose

$ docker-compose up -d

# invoke the service
$ curl -v http://localhost:8080

# shut down compose
$ docker-compose down

# to run this example in kubernetes

$ kubectl apply -f k8s.yml

# check that the pod is ready
$ kubectl get pods -w

# port-forward the port
$ kubectl port-forward svc/node-express-hello 8080:8080 2>/dev/null &

# invoke the service
$ curl -v http://localhost:8080

# kill the port-forward
$ pkill -f "port-forward"