Background #

Deployd modules are 100% compatible with regular node modules. This means you can use any of the 17,000+ node modules when building your Deployd app.

Hello World #

Any module in your app's node_modules folder will be loaded when the Deployd server starts.

You don't have to require() or load anything to instantiate your module. The following will log 'hello world' when you run dpd.

// /my-app/node_modules/hello.js
console.log('hello world');

Accessing the Server #

In order to do anything interesting you need a reference to the current Deployd server object. The server is always available at process.server. This means you don't need to require anything to use most of the internal APIs.

One Off Modules #

The simplest kind of module is a one-off module. These are easy to create but hard to reuse. Typically any behavior that is specific to just your app that can't be implemented using an existing module can be built with a simple one-off module.

Here's an example one off module that maintains a count of requests to the url /hits and writes it to a file every minute.

// /my-app/node_modules/hits.js
var fs = require('fs');
process.server.hits = 0;

process.server.on('request', function(req) {
  if(req.url === '/hits') {
    process.server.hits++;
  }
});

// write a file every minute
setInterval(function() {
  fs.writeFile('hits.json', JSON.stringify({hits: process.server.hits}));
}, 60000);

Reusable Modules #

Modules can also expose useful APIs of their own. The simplest way to create reusable modules is to define a Resource Type. Resource Types are exposed in the dashboard and are much easier to reuse, and you can share them with other Deployd developers. See the custom resource type guide for more info.

Debugging #

Deployd uses debug to log requests and show other internal debug info. To activate it you need to set the DEBUG env variable to *, for example:

process.env['DEBUG'] = '*';