Back in a pre-dev/ops era, application deployment via images and virtual appliances ruled the world. Amazon Web Services and VMware built their cloud empires on them. Flash forward to 2012. In today's fast-moving, agile environments, there’s zero tolerance for trade-offs between changes and repeatability. Machine images and other virtual appliances have become problematic, if not downright archaic. Or, in the words of Standing Cloud CEO Dave Jilk during a recent mainstage presentation at GlueCon 2012, virtual appliances are an "anachronistic, unmanageable bottleneck."
In the new Standing Cloud white paper The Transition from Virtual Appliances to Model-driven Deployment, Dave posits (as he did in a similar article in Virtualization Journal) that succeeding in the cloud will require a new approach — model-driven deployment. Sure, both approaches have benefits and shortcomings. But ultimately, model-driven deployment is more consistent with today’s agile, iterative, and deploy-frequently model of operations.
In The Transition from Virtual Appliances to Model-driven Deployment, Dave takes a deeper look at how images and virtual appliances work, including the creation of a “golden master” that makes deployment fast, easy and repeatable — but not flexible. He also lays out how model-driven deployment (or, more simply put, live scripted installations) mitigates the trade-off between efficiency and flexibility with its combination of abstraction and modularization. It also eliminates the need for a “golden master” which may require a rebuilding of the initial image.
While the paper stops short of calling virtual appliances "the Tar Pit of Despond," (as Dave did at Gluecon), it concludes by suggesting that organizations must transition from managing images as their primary means of deploying systems to an approach that uses flexible, maintainable scripts, not only for initial deployment but also for ongoing management of the system. The end result, he suggests, will be more efficient and reliable systems management. And more success in the cloud.