Add custom user agent headers

Author: jpadilla

lib/index.js

@@ -1,4 +1,5 @@
 var request = require('request');
+var exec = require('child_process').exec;
 
 var API_URL = 'https://api.filepreviews.io/v2';
 var FilePreviews;
@@ -20,6 +21,17 @@ FilePreviews = function(options) {
   }
 };
 
+FilePreviews.VERSION = require('../package.json').version;
+FilePreviews.CLIENT_UA_SERIALIZED = null;
+FilePreviews.CLIENT_UA = {
+  lang: 'node',
+  publisher: 'filepreviews',
+  bindings_version: FilePreviews.VERSION,
+  lang_version: process.version,
+  platform: process.platform,
+  uname: null
+};
+
 FilePreviews.prototype.log = function(msg) {
   if (this.debug) {
     console.log(msg);
@@ -82,13 +94,30 @@ FilePreviews.prototype.request = function(url, options, callback) {
     callback(body);
   }.bind(this);
 
+  var getClientUserAgent = function(cb) {
+    if (FilePreviews.CLIENT_UA_SERIALIZED) {
+      return cb(FilePreviews.CLIENT_UA_SERIALIZED);
+    }
+
+    exec('uname -a', function(err, uname) {
+      FilePreviews.CLIENT_UA.uname = uname || 'UNKNOWN';
+      FilePreviews.CLIENT_UA_SERIALIZED = JSON.stringify(FilePreviews.CLIENT_UA);
+      cb(FilePreviews.CLIENT_UA_SERIALIZED);
+    });
+  };
+
   var requestOptions = {
     url: url,
     method: _options.method || 'GET',
     json: true,
     auth: {
       username: this.apiKey,
       password: this.apiSecret
+    },
+    headers: {
+      'Accept': 'application/json',
+      'Content-Type': 'application/json',
+      'User-Agent': 'FilePreviews/v2 NodeBindings/' + FilePreviews.VERSION
     }
   };
 
@@ -98,13 +127,17 @@ FilePreviews.prototype.request = function(url, options, callback) {
 
   this.log('API request to: ' + url);
 
-  this._request(requestOptions, function(error, response, body) {
-    if (error) {
-      onError(error, response, body);
-    } else {
-      onSuccess(error, response, body);
-    }
-  });
+  getClientUserAgent(function(clientUA) {
+    requestOptions.headers['X-FilePreviews-Client-User-Agent'] = clientUA;
+
+    this._request(requestOptions, function(error, response, body) {
+      if (error) {
+        onError(error, response, body);
+      } else {
+        onSuccess(error, response, body);
+      }
+    });
+  }.bind(this));
 };
 
 FilePreviews.prototype.getAPIRequestData = function(url, options) {