Now the “container” concept has been smartly extended from cloud infrastructure to data and cloud software. A cloud software container can work as a portable module for cloud applications to move between hybrid cloud PaaS or be offered as a flexible component of PaaS. Many such designs and implementations are still in the making. An example today which just started gaining popularity is called Docker, a Linux-based open-source OS-virtualization implementation. It essentially functions as a middle-tier abstraction layer or wrapper to shield off the cloud platform complexities from the application developers. Within 15 months of its inception till today, the total downloads of its trial version have exceeded one million and the community is fast growing. There are a few major global supporters for such an implementation and the startup company in San Francisco recently got a new round of $40 million venture funding.

Compared with the prevailing concept of Virtual Machines for deploying cloud-based applications, the Docker “container” goals at making the applications easily portable among hybrid cloud platforms with agility, zero startup time and one-click management. Of course there are certain trade-offs with the benefits of portability and platform-neutrality. Since it uses kernel sharing for platform reach, some security controls have to be sacrificed. Also Docker only supports single-host applications because the “container package” can get a lot more complex with multi-server applications across platforms and it’s a hard problem to resolve. Some supplemental solution proposals are out there on the market to overcome the limitation. Still, the “software container” concept and solutions are very new and yet to be tested for any IT production situation.