Docker Gets Serious About Security

Two months after Docker brings in new faces to lead security efforts, a new benchmark for securing Docker container deployments debuts.


In March of this year, Nathan McCauley and Diogo Monica joined Docker Inc. to lead security efforts for the container virtualization vendor. Now, just over two months later, the first fruits of McCauley and Monica's efforts are becoming apparent with a new Center for Internet Security benchmark report for the Docker Engine 1.6.

McCauley together with VMware, Rakuten, Cognitive Scale and International Securities Exchange worked with the nonprofit Center for Internet Security to build the benchmark, which defines best practices for the safe and secure deployment of the Docker Engine as of the 1.6 release. Docker Engine is the core open-source container virtualization component for Docker, and the 1.6 release debuted on April 16, providing new labeling capabilities for virtualization container applications.

The Center for Internet Security (CIS) Docker Engine 1.6 Benchmark report is not a lightweight document, weighing in at a hefty 119 pages.

Pravin Goyal, senior member of Technical Staff at VMware and a co-author of the CIS Docker Benchmark, commented in a blog post that there are 84 recommendations in the benchmark.

"The aim of this security benchmark, like any other hardening guide or security documentation for any other vendor or product, is to highlight configuration parameters and other secure deployment considerations," Goyal wrote. "It is designed as a definitive reference guide for customers wanting to understand how to securely provision containers to Linux OSes in production."

The report identifies six key areas of best practices for Docker deployment. The first area is host configuration for the operating system on which the Docker Engine will be deployed. The CIS report recommends that Docker Engine users create a separate partition for containers and use an updated Linux kernel.

The second key area addressed by the CIS benchmark is Docker daemon configuration. The daemon is the system process the runs the Docker Engine. As a best practice, CIS recommends that system administrators restrict network traffic between containers and configure TLS (Transport Layer Security) authentication. Additionally as a third area of focus, there are best practices for Docker daemon configuration files to ensure proper file ownership.

The fourth key area is in container image and build file setup. The CIS benchmark recommends that administrators not install unnecessary packages in the container. The fifth area of focus deals with the container runtime, with the CIS Benchmark recommending the use mandatory access controls in Linux, including SELinux (Security Enhanced LInux) and AppArmor.

Finally, the benchmark's sixth section deals with ongoing Docker security operations. One of the key recommendations there is to perform regular security audits of the host system as well as the containers.

Docker Inc. has now also published a somewhat more concise introduction to the container security report that is only eight pages and provides users with an overview of how Docker can and should be securely deployed. Docker Inc.'s introduction to the container security document provides basic information on process restrictions, application image security and open-source security controls.

Going a step further, there is now a dedicated Docker security Web page that details the security reporting process for those who want to make responsible disclosure of vulnerabilities.

Overall, with the CIS benchmark, the introduction to the container security document and the dedicated security page, Docker is now moving into a new phase of maturity, where rigorous process and controls can be employed to provide security.

Sean Michael Kerner is a senior editor at eWEEK and Follow him on Twitter @TechJournalist.

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.