Gartner, lol
I imagine their policy is, you can't label something 100% crap, you must say something good to avoid burning bridges...
Analyst outfit Gartner has assessed Docker's security – and found the containerisation tool is sound but immature. Gartner's report, Security Properties of Containers Managed by Docker, published last week, finds “Linux containers are mature enough to be used as private and public PaaS” but “disappoint when it comes to secure …
...2015 will likely see the emergence of third-party tools... that harden the software by improving its manageability and by filling gaps for the kind of functions business expect.
The report matches up with what I have been reading about Docker (I haven't had the opportunity to play with it yet) in El Reg and elsewhere, that it is new tech with a reasonable amount of thought put into usability and design. It seems to be increasing in use. Unfortunately, because it is used in areas that can be very lucrative if compromised, it will come under increasing scrutiny by black hats. No surprises here as it is predictable. Still, it is interesting tech. I especially appreciate the analysis in the article concerning deploying Docker on top of VMs.