Running Selenium 4 in Docker containers is a common approach for creating scalable and isolated environments for web browser automation. Selenium 4 brings several improvements and features for Selenium users. Here’s how you can set up Selenium 4 with Docker:

1. Install Docker:

   • If you haven’t already, install Docker on your local machine or the server where you plan to run your Docker containers. You can download Docker from the official website for your specific platform.

2. Pull Selenium Docker Images:

   • Selenium provides official Docker images for various components, including the Selenium Server (standalone), Chrome, Firefox, and Edge. You can pull these images from Docker Hub using the following commands:
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     docker pull selenium/standalone-chrome docker pull selenium/standalone-firefox

3. Create a Docker Compose File (Optional):

   • Docker Compose allows you to define and manage multi-container Docker applications easily. You can create a docker-compose.yml file to define the Selenium Grid setup, which is a powerful way to manage multiple Selenium instances.
   • Here’s a simple example of a docker-compose.yml file:
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     version: '3' services: selenium-hub: image: selenium/hub:4.0.0-rc-1-20210323 ports: - "4444:4444" chrome: image: selenium/node-chrome:4.0.0-rc-1-20210323 volumes: - /dev/shm:/dev/shm depends_on: - selenium-hub firefox: image: selenium/node-firefox:4.0.0-rc-1-20210323 volumes: - /dev/shm:/dev/shm depends_on: - selenium-hub
     This setup defines a Selenium Grid with a hub and two nodes for Chrome and Firefox.

4. Start Selenium Grid:

   • Run the Selenium Grid using Docker Compose or individual docker run commands, depending on your setup.
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     docker-compose up -d

5. Run Your Selenium Tests:

   • Write your Selenium tests using your preferred programming language (e.g., Java, Python) and configure them to connect to the Selenium Grid at http://localhost:4444/wd/hub.
   • Specify the desired capabilities for your tests to target either Chrome or Firefox nodes.

6. Scale Selenium Nodes (Optional):

   • If you need to run tests in parallel or across different browsers, you can scale the number of nodes in your Docker Compose setup by adjusting the docker-compose.yml file.

7. Clean Up:

   • After you’ve finished running your tests, you can stop and remove the Docker containers and network.
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     docker-compose down