node-app-openshift-example

Build a Node.js Application for Openshift https://galvarado.com.mx/post/desplegar-aplicaciones-en-openshift/

Prerequisites

To follow this tutorial, you will need:

• Node.js and npm installed
• podman installed (To run the container locally for learning purposes)
• Podman installed
• An Openshift cluster where the application will run.
  • It should have the internal redistry exposed.
  • A DNS entry for the *.apps wildcard subdomain should be set ups.

Run the app locally

Run the app without containers locally. Inside the app dir, run:

npm install
node app.js

You should see the following output:

Example app listening on port 8080!

Access http://127.0.0.1:8080 to see the app running.

Containerize the app

Build the image

Builld the image with the following command:

podman build -t nodejs-demo .

Run the container

To use that image, run the container with:

podman run --name nodejs-demo -p 8090:8080 -d nodejs-demo

Access http://127.0.0.1:8080 to see the app running on the container.

Deploy to Openshift

Push the image

Login to Openshift:

oc login

Create a project:

oc project demo-project

Get the default route from the Openshift registry:

oc get route default-route -n openshift-image-registry

Save the route in a varibale to further usage:

HOST=$(oc get route default-route -n openshift-image-registry --template='{{ .spec.host }}')

Login to the registry:

podman login -u $(oc whoami) -p $(oc whoami -t) --tls-verify=false $HOST

You should see the following message:

Login Succeeded!

Tag the image:

podman tag nodejs-demo:$HOST/demo-project/nodejs-demo

Push the image:

podman push $HOST/demo-project/nodejs-demo

Deploy and expose the app

Apply the manifest orchestration/deployment:

oc apply -f orchestration/deployment,yml

Create a service:

oc expose deployment nodejs-demo --name nodejs-demo-svc --port 8080 --target-port=8080

Expose the app through a route:

oc expose service nodejs-demo-svc -l route=external --name=nodejs-demo

Access the application http://nodejs-demo-demo-project.apps.CLUSTER_FQDN.com/

run.sh

A script to automate the process is available:

./run.sh --help

To deploy the app locally use dev as an argument, add --build if you want to build the image before deploying.

./run.sh dev --build

Prod

./run.sh prod --build