Getting Started with Hub and Nodes

Getting Started with Hub & Nodes

This is a step-by-step introduction to using the official Selenium Docker images using a basic hub/node configuration.

Step 1: Pulling down the hub / nodes

$ docker pull selenium/hub selenium/node-chrome selenium/node-firefox

This will pull from hub.docker.com, the three official images. Note: when you omit a version at the end, it will default to "latest" tag. To specify a version, simply add :<version> at the end. E.g: selenium/hub:3.3.1

Step 2: Bringing up the hub / nodes

Now that we have the images pulled down, let's run them.

Running the Hub

$ docker run -p 4444:4444 --name selenium-hub selenium/hub
# Run the hub, forwarding the "4444" port from the docker container to the host machine.

Running the Chrome node

$ docker run --link selenium-hub:hub selenium/node-chrome
# Run the chrome node and link it to the `--name` we specified for the hub.

Running the Firefox node

$ docker run --link selenium-hub:hub selenium/node-chrome
# Run the firefox node and link it to the `--name` we specified for the hub.

Step 3: Running tests

Note: Please consult the official documentation if you are having issues with the following code.

Java

import org.openqa.selenium.remote.RemoteWebDriver;
import org.openqa.selenium.remote.DesiredCapabilities;

public class MyTest {

  Capabilities chromeCapabilities = DesiredCapabilities.chrome();
  Capabilities firefoxCapabilities = DesiredCapabilities.firefox();

  public static void main() {
    WebDriver chrome = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), chromeCapabilities);
    WebDriver firefox = new RemoteWebDriver(new URL("http://localhost:4444/wd/hub"), firefoxCapabilities);

    // run against chrome
    chrome.get("https://www.google.com");
    System.out.println(chrome.getTitle());

    // run against firefox
    firefox.get("https://www.google.com");
    System.out.println(firefox.getTitle());
  
    chrome.quit();
    firefox.quit();
  }
}

Ruby

require 'selenium-webdriver'

chrome_capabilities = Selenium::WebDriver::Remote::Capabilities.chrome()
firefox_capabilities = Selenium::WebDriver::Remote::Capabilities.firefox()

chrome = Selenium::WebDriver.for(:remote, :url => 'http://localhost:4444/wd/hub', :desired_capabilities => chrome_capabilities)
firefox = Selenium::WebDriver.for(:remote, :url => 'http://localhost:4444/wd/hub', :desired_capabilities => firefox_capabilities)

chrome.get('http://google.com')
puts chrome.title

firefox.get('http://google.com')
puts firefox.title

chrome.quit
firefox.quit