Selenium Webdriver 动态设置 Proxy

Step 1: Visiting "about:config"

driver.get("about:config");

Step 2 : Run script that changes proxy

var setupScript=`var prefs = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);
prefs.setIntPref("network.proxy.type", 1);
prefs.setCharPref("network.proxy.http", "${proxyUsed.host}");
prefs.setIntPref("network.proxy.http_port", "${proxyUsed.port}");
prefs.setCharPref("network.proxy.ssl", "${proxyUsed.host}");
prefs.setIntPref("network.proxy.ssl_port", "${proxyUsed.port}");
prefs.setCharPref("network.proxy.ftp", "${proxyUsed.host}");
prefs.setIntPref("network.proxy.ftp_port", "${proxyUsed.port}");
//running script below  
driver.executeScript(setupScript);
//sleep for 1 sec
driver.sleep(1000);

Step 3: : Visit your site

driver.get("https://whatismyip.com");

参考：https://stackoverflow.com/questions/29776607/python-selenium-webdriver-changing-proxy-settings-on-the-fly