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To improve the security of your Docker containers, you can follow these best practices:

  1. Use minimal base images: Instead of using full-fledged base images, choose minimal base images like alpine or slim variants, which contain only essential components.

  2. Regularly update your base images: Keep your base images up to date with the latest security patches. Enable automated image scanning to receive notifications about known vulnerabilities.

  3. Use specific, non-root users: Always create a specific, non-root user for running your application inside the container, as you did in the Dockerfile you provided.

  4. Limit the container capabilities: By default, Docker containers run with a limited set of capabilities, but you can further restrict them using the --cap-drop and --cap-add flags when running a container. For example:

docker run --cap-drop=all --cap-add=NET_BIND_SERVICE --cap-add=SETGID --cap-add=SETUID your-image-name
  1. Use read-only filesystems: If your application does not require write access to the filesystem, you can mount it as read-only using the --read-only flag:
docker run --read-only your-image

  1. Use a private repository for sensitive images: Store sensitive images in a private repository with access controls to prevent unauthorized access.

  2. Enable Docker Content Trust: Enable Docker Content Trust to ensure that you are pulling only signed images:

export DOCKER_CONTENT_TRUST=1
  1. Use network segmentation: Isolate your containers in separate networks to limit communication between unrelated services. Use the --network flag to define the network when running a container:

docker network create my-network
docker run --network=my-network your-image-name
  1. Limit resource usage: Set resource limits for CPU, memory, and I/O using the --cpus, --memory, and --blkio-weight flags to prevent a container from consuming excessive resources:
docker run --cpus=2 --memory=256M --blkio-weight=500 your-image-name
  1. Use AppArmor or SELinux profiles: Use AppArmor or SELinux profiles to restrict the actions a container can perform on the host system. Define the security profile using the --security-opt flag:
docker run --security-opt apparmor=my_custom_profile your-image-name

By following these best practices, you can improve the security of your Docker containers and minimize potential attack surfaces.