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Version: v3

Developing with Node.JS

Step 0. Creating the initial source code (optional)

We will create the example source code by using some popular frameworks.

This is optional and you may use an existing project instead or a starter project from odo init.

For Node.JS we will use the Express framework for our example.

  1. Install Express:
npm install express --save
$ npm install express --save

added 57 packages, and audited 58 packages in 6s

7 packages are looking for funding
run `npm fund` for details

found 0 vulnerabilities
  1. Generate an example project:
npx express-generator
$ npx express-generator
warning: the default view engine will not be jade in future releases
warning: use `--view=jade' or `--help' for additional options

create : public/
create : public/javascripts/
create : public/images/
create : public/stylesheets/
create : public/stylesheets/style.css
create : routes/
create : routes/index.js
create : routes/users.js
create : views/
create : views/error.jade
create : views/index.jade
create : views/layout.jade
create : app.js
create : package.json
create : bin/
create : bin/www

install dependencies:
$ npm install

run the app:
$ DEBUG=express:* npm start

Your source code has now been generated and created in the directory.

Step 1. Connect to your cluster and create a new namespace or project

Before starting you should make sure that odo is connected to your cluster and that you have created a new namespace (or project if you are using OpenShift).

Creating a new namespace

If you are using Kubernetes, you can create a new namespace with the odo create namespace command.

$ odo create namespace odo-dev
✓ Namespace "odo-dev" is ready for use
✓ New namespace created and now using namespace: odo-dev

Step 2. Initializing your application (odo init)

Now we'll initialize your application by creating a devfile.yaml to be deployed.

odo handles this automatically with the odo init command by autodetecting your source code and downloading the appropriate Devfile.

Note: If you skipped Step 0, select a "starter project" when running odo init.

Let's run odo init and select Node.JS:

odo init
$ odo init
 /  \__     Initializing new component
 \__/  \    Files: Source code detected, a Devfile will be determined based upon source code autodetection

/ \__/ odo version: v3.0.0~beta3 \__/

Interactive mode enabled, please answer the following questions: Based on the files in the current directory odo detected Language: javascript Project type: nodejs The devfile "nodejs" from the registry "DefaultDevfileRegistry" will be downloaded. ? Is this correct? Yes ✓ Downloading devfile "nodejs" from registry "DefaultDevfileRegistry" [501ms] Current component configuration: Container "runtime": Opened ports: - 3000 Environment variables: ? Select container for which you want to change configuration? NONE - configuration is correct ? Enter component name: my-nodejs-app Your new component 'my-nodejs-app' is ready in the current directory. To start editing your component, use 'odo dev' and open this folder in your favorite IDE. Changes will be directly reflected on the cluster.

A devfile.yaml has now been added to your directory and now you're ready to start development.

Step 3. Developing your application continuously (odo dev)

Now that we've generated our code as well as our Devfile, let's start on development.

odo uses inner loop development and allows you to code, build, run and test the application in a continuous workflow.

Once you run odo dev, you can freely edit code in your favourite IDE and watch as odo rebuilds and redeploys it.

Let's run odo dev to start development on your Node.JS application:

odo dev
$ odo dev
 /  \__     Developing using the my-nodejs-app Devfile
 \__/  \    Namespace: default

/ \__/ odo version: v3.0.0~beta3 \__/

↪ Deploying to the cluster in developer mode ✓ Waiting for Kubernetes resources [3s] ✓ Syncing files into the container [330ms] ✓ Building your application in container on cluster [4s] ✓ Executing the application [1s] Your application is now running on the cluster - Forwarding from -> 3000 Watching for changes in the current directory /Users/user/nodejs Press Ctrl+c to exit `odo dev` and delete resources from the cluster

You can now access the application at in your local browser and start your development loop. odo will watch for changes and push the code for real-time updates.

You can now follow the advanced guide to deploy the application to production.