Tips for Node.js Applications

Page last updated: December 24, 2015

This page assumes you are using cf CLI v6.

This topic provides Node-specific information to supplement the general guidelines in the Deploy an Application topic.

Application Package File

Cloud Foundry expects a package.json in your Node.js application. You can specify the version of Node.js you want to use in the engine node of your package.json file. As of July, 2015, and buildpack version 1.5.0, Cloud Foundry uses Node.js version 0.12.7 by default. See the GitHub Node.js buildpack page for current information.

Example package.json file:

{
  "name": "first",
  "version": "0.0.1",
  "author": "Demo",
  "dependencies": {
    "express": "3.4.8",
    "consolidate": "0.10.0",
    "express": "3.4.8",
    "swig": "1.3.2"
  },
  "engines": {
    "node": "0.12.7",
    "npm": "2.7.4"
  }
}

Application Port

You must use the PORT environment variable to determine which port your application should listen on. In order to also run your application locally, you may want to make port 3000 the default:

app.listen(process.env.PORT || 3000);

Application Start Command

Node.js applications require a start command. You can specify a Node.js applications’s web start command in a Procfile or in the application deployment manifest.

You will be asked if you want to save your configuration the first time you deploy. This will save a manifest.yml in your application with the settings you entered during the initial push. Edit the manifest.yml file and create a start command as follows:

---
applications:
- name: my-app
  command: node my-app.js
... the rest of your settings ...

Alternately, specify the start command with cf push -c.

$ cf push my-app -c "node my-app.js"

Application Bundling

You do not need to run npm install before deploying your application. Cloud Foundry will run it for you when your application is pushed. If you would prefer to run npm install and create a node_modules folder inside of your application, this is also supported.

Solving Discovery Problems

If Cloud Foundry does not automatically detect that your application is a Node.js application, you can override the auto-detection by specifying the Node.js buildpack.

Add the buildpack into your manifest.yml and re-run cf push with your manifest:

---
applications:
- name: my-app
  buildpack: https://github.com/cloudfoundry/nodejs-buildpack
... the rest of your settings ...

Alternately, specify the buildpack on the command line with cf push -b:

$ cf push my-app -b https://github.com/cloudfoundry/nodejs-buildpack

Binding Services

Refer to Configure Service Connections for Node.js.

About the Node.js Buildpack

For information about using and extending the Node.js buildpack in Cloud Foundry, see the nodejs-buildpack repo.

You can find current information about this buildpack on the Node.js buildpack release page in GitHub.

The buildpack uses a default Node.js version of 0.12.7. To specify the versions of Node.js and npm an application requires, edit the application’s package.json, as described in “node.js and npm versions” in the nodejs-buildpack repo.

Environment Variables

You can access environments variable programmatically.

For example, you can obtain VCAP_SERVICES like this:

process.env.VCAP_SERVICES

Environment variables available to you include both those defined by the DEA and those defined by the Node.js buildpack, as described below.

BUILD_DIR

Directory into which Node.js is copied each time a Node.js application is run.

CACHE_DIR

Directory that Node.js uses for caching.

PATH

The system path used by Node.js.

PATH=/home/vcap/app/bin:/home/vcap/app/node_modules/.bin:/bin:/usr/bin