Configuring service connections for Node.js apps

You can bind a data source to a Node.js application that is deployed and running on Cloud Foundry.

Parse VCAP_SERVICES for credentials

You must parse the VCAP_SERVICES environment variable in your code to get the required connection details such as host address, port, user name, and password.

For example, if you are using PostgreSQL, your VCAP_SERVICES environment variable might look something like this:

{
    "mypostgres": [{
        "name": "myinstance",
        "credentials": {
            "uri": "postgres://myusername:mypassword@host.example.com:5432/serviceinstance"
        }
    }]
}

This example JSON is simplified; yours might contain additional properties.

Parse with cfenv

The cfenv package provides access to Cloud Foundry application environment settings by parsing all the relevant environment. The settings are returned as JavaScript objects. cfenv provides reasonable defaults when running locally, as well as when running as a Cloud Foundry application.

For more information, see the npm website.

Manual parsing

First, parse the VCAP_SERVICES environment variable.

For example:

var vcap_services = JSON.parse(process.env.VCAP_SERVICES)

Then pull out the credential information required to connect to your service. Each service packages requires different information. If you are working with Postgres, for example, you need a uri to connect. You can assign the value of the uri to a variable as follows:

var uri = vcap_services.mypostgres[0].credentials.uri

Once assigned, you can use your credentials as you would normally in your program to connect to your database.

Connecting to a service

You must include the appropriate package for the type of services your application uses.

For example:

Rabbit MQ through the amqp module
mongoose modules
MySQL through the mysql module
Postgres through the pg module
Redis through the redis module

Add dependency to package.json

Edit package.json and add the intended module to the dependencies section. Normally, only one is necessary, but for the sake of the example, add all of them:

{
  "name": "hello-node",
  "version": "0.0.1",
  "dependencies": {
    "express": "*",
    "mongodb": "*",
    "mongoose": "*",
    "mysql": "*",
    "pg": "*",
    "redis": "*",
    "amqp": "*"
  },
  "engines": {
    "node": "0.8.x"
  }
}

You must run npm shrinkwrap to regenerate your npm-shrinkwrap.json file after you edit package.json file.