Matthew Garrett considers the security of Linux containers on his blog. While the attack surface of containers is likely to always be larger than that of hypervisors, that difference may not matter in practice, but it’s going to take some work to get there:
- Strong auditing and aggressive fuzzing of containers under realistic configurations
- Support for meaningful nesting of Linux Security Modules in namespaces
- Introspection of container state and (more difficult) the host OS itself in order to identify compromises
These aren’t easy jobs, but they’re important, and I’m hoping that the lack of obvious development in areas like this is merely a symptom of the youth of the technology rather than a lack of meaningful desire to make things better. But until things improve, it’s going to be far too easy to write containers off as a “convenient, cheap, secure: choose two” tradeoff. That’s not a winning strategy.