[addon] moves rd resolver to addon

addon/lib/request_helper.js

@@ -0,0 +1,20 @@
+const UserAgent = require('user-agents');
+
+const PROXY_HOSTS = process.env.PROXY_HOSTS && process.env.PROXY_HOSTS.split(',');
+const PROXY_USERNAME = process.env.PROXY_USERNAME;
+const PROXY_PASSWORD = process.env.PROXY_PASSWORD;
+const userAgent = new UserAgent();
+
+function getRandomUserAgent() {
+  return userAgent.random().toString();
+}
+
+function getRandomProxy() {
+  if (PROXY_HOSTS && PROXY_HOSTS.length && PROXY_USERNAME && PROXY_PASSWORD) {
+    return `http://${PROXY_USERNAME}:${PROXY_PASSWORD}@${PROXY_HOSTS[Math.floor(Math.random() * PROXY_HOSTS.length)]}`;
+  }
+  console.warn('No proxy configured!');
+  return undefined;
+}
+
+module.exports = { getRandomUserAgent, getRandomProxy };