Why do we require non-root user in the docker file

Question

How can I add a non-root user in a Dockerfile while ensuring proper permissions and security? Steps

Daniel Wright · Answer

Having a non-root user in a Dockerfile is essential for enhancing security and adhering to the principle of least privilege. By default, Docker runs containers as the root user, which can pose security risks if an attacker gains access to the container. Running processes as a non-root user limits the potential impact of security breaches within the container. To add a non-root user in a Dockerfile while ensuring proper permissions and security, you can follow these steps: 1. Create a non-root user: You can create a non-root user using the `USER` instruction in the Dockerfile. It is recommended to create a dedicated user for running the container processes. # Create a new user named 'appuser' RUN adduser --disabled-password appuser 2. Switch to the non-root user: After creating the non-root user, switch to that user using the `USER` instruction. USER appuser 3. Set proper permissions: Ensure that the non-root user has appropriate permissions to access the necessary files and directories within the container. You can adjust file permissions using the `chmod` command as needed. 4. Build the Docker image: Once you have added the non-root user in the Dockerfile and set up the necessary permissions, build the Docker image with the following command: docker build -t your_image_name . By following these steps, you can enhance the security of your Docker containers by running processes as a non-root user. This practice helps minimize the impact of potential security vulnerabilities within the container and improves overall security posture. If you have any further questions or need additional clarification, feel free to ask!