Configuring Service Connections for Node.js

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This guide is for developers who wish to bind a data source to a Node.js application 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 may 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.

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 will 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 via the amqp module
  • Mongo via the mongodb and mongoose modules
  • MySQL via the mysql module
  • Postgres via the pg module
  • Redis via the redis module

Add the Dependency to package.json

Edit package.json and add the intended module to the dependencies section. Normally, only one would be necessary, but for the sake of the example we will 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.

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