Running containers as a non-root user and scanning images for vulnerabilities.
Security is paramount when working with containers. By default, containers are run by the `root` user, which is a significant security risk. If an attacker compromises your application within the container, they would have root privileges inside that container, potentially allowing them to escalate their attack. A fundamental best practice is to run your containerized processes as a non-root user. You can achieve this in your Dockerfile by creating a dedicated user and group (`RUN addgroup -S appgroup && adduser -S appuser -G appgroup`) and then switching to that user with the `USER appuser` instruction before your final `CMD` or `ENTRYPOINT`. Another critical aspect of container security is vulnerability scanning. Your base images, and even the application dependencies you add, can contain known security vulnerabilities (CVEs). It's essential to integrate image scanning into your workflow. Tools like Docker Scout, Trivy, or Snyk can be used to scan your Docker images, identify vulnerable packages, and provide recommendations for fixing them. Regularly scanning and updating your images to patch vulnerabilities is a non-negotiable part of maintaining a secure containerized environment. These practices help to significantly reduce the attack surface of your applications.