Among the big pieces of news that Docker Inc. announced at its DockerCon EU conference in November 2015 was its Project Nautilus effort to scan Docker repositories for security vulnerabilities. Now six months later, the company is making Nautilus generally available under the product name Docker Security Scanning. And Docker is complementing the new security product with an update to Docker Bench, a container best practices security tool, further improving the overall security tooling for Docker.

"What was announced at DockerCon was the use of Nautilus for Docker Official Repos [repositories] only and did not have a workflow that ties to the end-to-end software supply chain," Nathan McCauley, director of security at Docker, told eWEEK.

Docker Security Scanning is available to Docker Cloud private repository customers for a limited time free trial, eventually expanding to include all Docker Cloud repository users, according to McCauley. Pricing starts at $2 per repository as an add-on service for private repository plans. Docker Security Scanning will also be available as an integrated feature in Docker Datacenter, which is Docker Inc.'s premier commercial product that officially debuted in February.

Docker Security Scanning's goal is to help developers and enterprises find and identify known vulnerabilities in Docker container images. It is being applied to all the official images on the Docker Hub repository for container images, McCauley said. The general availability adds the ability for Docker Cloud subscribers to scan their private repositories.

"Previously, IT operations would have to rely on the information published by each ISV on the state of their content and have to actively monitor the CVEs [Common Vulnerability and Exposures] for each one," he said. "Docker Security Scanning looks for known CVEs by generating a bill of materials for Docker images using a static analysis scan of the image itself."

Docker Security Scanning currently only looks for known vulnerabilities that have a CVE. At this time, no dynamic analysis is performed on the Docker container image looking for potentially unknown vulnerabilities, McCauley said. Docker Inc. rival CoreOS has a similar effort known as Clair, which was updated in March to the 1.0 milestone.

While known vulnerabilities are a risk, so too are known misconfiguration issues, which is where the Docker Bench tool comes into play. Docker Bench was first announced a year ago alongside a Center for Internet Security (CIS) benchmark report on best practices for Docker deployment security. The original CIS report was aligned with the Docker 1.6 release, and a new CIS benchmark is now out, updated for the recent Docker 1.11. McCauley noted that the new report adds recommendations for a number of new features that have rolled out since the previous version.

"This covers things like enabling user namespaces and using authorization plug-ins," he said. "Additionally, checks have been added to recommend against disabling new isolation features like seccomp."

Overall, McCauley noted that Docker Bench and Docker Security Scanning cover different aspects of securing Docker infrastructure. Docker Bench allows for scanning of a Docker host's settings.

"Docker Bench is about best practices for configuring a host on which you will run Docker containers," he said. "Docker Security Scanning is responsible for scanning Docker container images themselves and letting users know if there is any known vulnerable software within their container image."

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