Docker Bench for Security

The Docker Bench for Security is a script that checks for dozens of common best-practices around deploying Docker containers in production. The tests are all automated, and are inspired by the CIS Docker Community Edition Benchmark v1.1.0. We are releasing this as a follow-up to our Understanding Docker Security and Best Practices blog post.

We are making this available as an open-source utility so the Docker community can have an easy way to self-assess their hosts and docker containers against this benchmark.

Running Docker Bench for Security

We packaged docker bench as a small container for your convenience. Note that this container is being run with a lot of privilege -- sharing the host's filesystem, pid and network namespaces, due to portions of the benchmark applying to the running host. Don't forget to adjust the shared volumes according to your operating system, for example it might not use systemd.

The easiest way to run your hosts against the Docker Bench for Security is by running our pre-built container:

docker run -it --net host --pid host --userns host --cap-add audit_control \
    -e DOCKER_CONTENT_TRUST=$DOCKER_CONTENT_TRUST \
    -v /var/lib:/var/lib \
    -v /var/run/docker.sock:/var/run/docker.sock \
    -v /usr/lib/systemd:/usr/lib/systemd \
    -v /etc:/etc --label docker_bench_security \
    docker/docker-bench-security

Docker bench requires Docker 1.13.0 or later in order to run.

Note that when distributions doesn't contain auditctl, the audit tests will check /etc/audit/audit.rules to see if a rule is present instead.

Distribution specific Dockerfiles that fixes this issue are available in the distros directory.

The distribution specific Dockerfiles may also help if the distribution you're using haven't yet shipped Docker version 1.13.0 or later.

Docker Bench for Security options

  -h           optional  Print this help message
  -l FILE      optional  Log output in FILE
  -c CHECK     optional  Comma delimited list of specific check(s)
  -x EXCLUDE   optional  Comma delimited list of patterns within a container to exclude from check

By default the Docker Bench for Security script will run all available CIS tests and produce logs in the current directory named docker-bench-security.sh.log.json and docker-bench-security.sh.log. The CIS based checks are named check_<section>_<number>, e.g. check_2_6 and community contributed checks are named check_c_<number>. A complete list of checks are present in functions_lib.sh.

sh docker-bench-security.sh -l /tmp/docker-bench-security.sh.log -c check_2_2

Note that when submitting checks, provide information why it is a reasonable test to add and please include some kind of official documentation verifying that information.

Building Docker Bench for Security

If you wish to build and run this container yourself, you can follow the following steps:

git clone https://github.com/docker/docker-bench-security.git
cd docker-bench-security
docker build -t docker-bench-security .
docker run -it --net host --pid host --cap-add audit_control \
    -e DOCKER_CONTENT_TRUST=$DOCKER_CONTENT_TRUST \
    -v /var/lib:/var/lib \
    -v /var/run/docker.sock:/var/run/docker.sock \
    -v /usr/lib/systemd:/usr/lib/systemd \
    -v /etc:/etc --label docker_bench_security \
    docker-bench-security

or use Docker Compose:

git clone https://github.com/docker/docker-bench-security.git
cd docker-bench-security
docker-compose run --rm docker-bench-security

Also, this script can also be simply run from your base host by running:

git clone https://github.com/docker/docker-bench-security.git
cd docker-bench-security
sudo sh docker-bench-security.sh

This script was built to be POSIX 2004 compliant, so it should be portable across any Unix platform.