A Brief about the Docker Selenium Tutorial:
In one of our prior tutorials, we explained how Selenium Grid permits us to execute test cases on various operating systems and browsers. Nonetheless, this tutorial will concentrate on Docker integration with Selenium Grid, providing an in-depth insight into Docker, including how to download, install, and link it with Selenium Grid. For clarity and ease of understanding, we have incorporated relevant screenshots and illustrative visuals.
Recommended IPTV Service Providers
- IPTVGREAT – Rating 4.8/5 ( 600+ Reviews )
- IPTVRESALE – Rating 5/5 ( 200+ Reviews )
- IPTVGANG – Rating 4.7/5 ( 1200+ Reviews )
- IPTVUNLOCK – Rating 5/5 ( 65 Reviews )
- IPTVFOLLOW -Rating 5/5 ( 48 Reviews )
- IPTVTOPS – Rating 5/5 ( 43 Reviews )
Covered Topics:
Understanding Selenium Grid
Selenium Grid facilitates the distribution of test cases across multiple machines (nodes) via a central system (hub). When all the test cases are executed on a single device, they may be hampered by limitations, and a single machine may not be adequate. Selenium Grid resolves this by enabling the distribution of test cases across different machines.
Practical Usage of Selenium Grid
A few years back, with the prohibition of Google products in China, companies developing web systems for China had to test their systems using browsers other than Google Chrome. These included Internet Explorer, Firefox, and Opera. Selenium Grid proved highly beneficial in this situation, allowing test cases to be run on different browsers.
Docker: An Overview
Docker, a tool for containerization, allows developers to bundle applications with their dependencies, libraries, and other necessary components into a container. Utilizing Docker, applications can be effectively deployed, scaled, and run consistently across various environments.
Setting up a Selenium Grid typically requires hosting and connecting multiple virtual machines (nodes) to the hub. In addition, the Selenium server jar file needs to be downloaded and run on each machine. This task can be expensive and time-consuming. By simplifying the setup and reducing cost and time requirements, Docker offers a solution to these problems.
Launched in 2013 as an open-source tool, Docker is widely employed by developers and system engineers for a variety of purposes. In this tutorial, we will be using Docker for software testing and automation.
Preconditions for Docker Selenium Tutorial
Prior to commencing with the Docker Selenium tutorial, ensure the following prerequisites are complied with:
- Your machine is installed with JDK 1.7 or a newer version
- Chrome and Firefox browsers are installed
- Selenium WebDriver and TestNG-based test cases are ready
- Testng.xml file is configured to execute test cases simultaneously
How to Download Docker for Windows
To execute Docker commands, the Docker toolbox, which comprises the Docker quick-start terminal should be installed. The Docker toolbox can be downloaded from the official website: Docker.
During the installation process, several checkboxes will appear. Make sure to select all the checkboxes for successful installation. Upon installation, you will find three Docker toolbox icons on your machine.
After the Docker toolbox has been installed, open the Docker quick-start terminal. The first-time configuration of your local machine in the terminal might take some time. Wait until the terminal window pops up.
You have now successfully configured Docker!
Installing Docker Images
In a regular Selenium Grid setup (without Docker), you need to configure the Selenium hub and browser nodes. Similarly, in a Docker-based Selenium Grid, it is required to install hub and browser node images in the Docker container.
Before proceeding further, install the following five Docker images:
- Image of Selenium hub
- Image of Selenium node-firefox
- Image of Selenium node-chrome
- Image of Selenium node-firefox-debug
- Image of Selenium node-chrome-debug
To locate and install these images, visit the Docker Hub and search for the required images by name. Once found, copy the Docker pull command for each image and paste it into the Docker quick-start terminal for installing the images. Wait until all images are downloaded and installed in your Docker container.
Ensure that all five images are downloaded successfully. You can confirm the downloaded images by executing the command Docker Images in the terminal.
Initializing Selenium Hub
To initiate the Selenium hub in the Docker container, use the command below:
docker run -d -p 4444:4444 –name selenium-hub selenium/hub
After running this command, Selenium hub will be accessible from the Docker container. To verify, open your browser and check the following URL: http://192.168.99.100:4444/grid/console (replace 192.168.99.100 with your IP address).
Launching Selenium Nodes
When the Selenium hub is live, we need to initiate the Selenium nodes in the Docker container. In this tutorial, we propose to initiate both Chrome node and Firefox node.
The command below initiates the Chrome node:
docker run -d –link selenium-hub:hub selenium/node-chrome
The command below initiates the Firefox node:
docker run -d –link selenium-hub:hub selenium/node-firefox
Once both nodes are active, refreshing the browser will show Chrome and Firefox nodes listed in Selenium hub.
In case of errors during image installation or node initiation, reinstall and relaunch the specific image.
Setting Up Selenium Tests
Create Selenium test scripts as you normally would, adhering to the guidelines mentioned in our Selenium Grid tutorial. Set the needed capabilities for your tests to aim at the specific browsers created using Docker. Configuration of your XML file to execute tests in parallel is optional.
Sample Selenium Test Script:
Upon completion of all the steps, run your test script. The test will be executed on different Docker-created browsers. The VNC viewer will simultaneously display the browser actions.
Final Thoughts
For executing test cases on various machines and browsers, especially when dealing with a high volume of test cases, Selenium Grid is a phenomenal tool. However, the setup and configuration of Selenium Grid can be costly and time demanding. Docker addresses this by making the setup process straightforward and reducing costs. This tutorial elucidates all necessary steps for successful integration of Docker with Selenium Grid.