nodejs server side proxy example using restify, showing a proxy to smarty streets address service

gistfile1.txt

// NODE.JS - SMARTY STREETS SERVER SIDE PROXY EXAMPLE
// 
// Smarty streets does not currently support HTTP OPTIONS.  Because of this, 
// if setting custom headers, it cannot be called from a browser-side library 
// like AngularJS.
// 
// This is a server side proxy for smarty-streets.  It takes the request 
// query string and passes it on to Smarty Streets along with any of the
// custom headers that Smarty Streets currently supports.
// 
// This sample code only depends on the external restify library.  It is a
// sample pattern for proxying any request using restify and redirecting to
// another service.

var restify = require('restify');
var querystring = require('querystring');
var https = require('https');
var http = require('http');
var url = require('url');

var port        =  '8080';
var server = restify.createServer({
    name: "ProxyService"
});
server.use(restify.acceptParser(server.acceptable));
server.use(restify.gzipResponse());
server.pre(restify.pre.userAgentConnection());


// Generic request function
// host, endpoint, method, data, headers, success) {
function proxyRequest(req, res, proxyOptions) {

    var options = {};
    options.host = proxyOptions.host;
    options.path = proxyOptions.endpoint + '?' + querystring.stringify(proxyOptions.query);
    options.method = proxyOptions.method;
    options.headers = proxyOptions.headers;

    console.log("URL: ", options.host+options.path);

    // determine whether to use https
    //
    if (proxyOptions.https) {
        var protocol = https
    }else{
        var protocol = http
    };

    var req = protocol.request(options, function(res) {
        var responseString = '';
        res.on('data', function(data) {
          responseString += data;
        });
        res.on('end', function() {
          proxyOptions.callback(responseString);
        });
        req.on('error', function(e) {
          console.error(e);
        });
    });

    req.end();
};


server.get('/street-address', function respond(req, res, next){
    var auth        =  {'auth-Id': 'insert authstring here',
                        'auth-token': 'insert auth token here'};
    var testData  = {'street': '1600 Amphitheatre Parkway','street2': '','city': 'Mountain View','state': 'CA','zipcode': '','candidates': 10};
    var extraHeaders     =  { 'Content-Type': 'application/json' };

    var options = {
        host: 'api.smartystreets.com',
        method: 'GET',
        endpoint: '/street-address',
        query: {},
        https: true,
        headers: {},
        callback: function() {}
    };

    // add the authcode
    options.query = auth;

    // add testdata to query string if empty
    if (!url.parse(req.url, true).query.street) {
        // add the test data string
        options.query = collect(options.query, testData);
    };

    //add extra headers
    options.headers = extraHeaders;

    //look for custom smarty streets headers in the request
    var copyHeaders = ['x-standardize-only', 'x-include-invalid', 'Accept', 'x-accept-keypair', 'x-suppress-logging'], hdr;
    for (var i=0; i<copyHeaders.length; i++ ) {
        hdr = copyHeaders[i];
        if (req.headers.hasOwnProperty(hdr)) {
            options.headers[hdr] = req.headers[hdr];
        }
    }

    // set the call back functionality
    options.callback = function(responseData) {
        res.send( JSON.parse(responseData) );
        res.end();
        return next();
    };
    // proxy the request to smartystreets using https
    proxyRequest(req, res, options);
});

//
// COLLECT - object concat
//
function collect(ob1, ob1) {
    var ret = {},
    len = arguments.length,
    arg,
    i = 0,
    p;

    for (i = 0; i < len; i++) {
      arg = arguments[i];
      if (typeof arg !== "object") {
        continue;
      }
      for (p in arg) {
        if (arg.hasOwnProperty(p)) {
          ret[p] = arg[p];
        }
      }
    }
    return ret;
};


server.listen(port, function(){
    console.log("===========================================================================");
    console.log('%s listening at %s ', server.name , server.url);
});