Containers do have certain advantages over virtual machines, not the least of which is size. Virtual machines require full operating systems and can run into gigabytes. In virtualization each package contains an operating system, while containers only require megabytes and can run off a single OS. This means that multiple containers can be hosted by a single server and in far greater numbers than virtual machines. You can run a single operating system with multiple containers sharing the same operating system kernel. Each container can write to the system independently, while shared OS elements are read only. This is a much more efficient use of resources.

However, it does present a security problem. Sharing an operating system means that security can be circumvented, as there is no user ID isolation. This can lead to root level privileges being used as an open door.

Nevertheless, the sheer convenience of containers means that they are here to stay. It also means that there are a number of groups who are working on ways to make containers more useful and secure. Dashboards, management consoles and integrated registries are on offer, along with additional tools to automate updates and deployment.

Bit by bit containers are becoming a stock item in the software development toolbox. While they may never replace virtualization, they do offer advantages of their own, advantages that software development teams increasingly cannot do without.