Lift and shift – containerizing a legacy app

We can’t always start from scratch and develop a brand-new application. More often than not, we find ourselves with a huge portfolio of traditional applications that are up and running in production and provide mission-critical value to the company or the customers of the company. Often, those applications are organically grown and very complex. Documentation is sparse, and nobody wants to touch such an application. Often, the saying “Never touch a running system” applies. Yet, the market needs change, and with that arises the need to update or rewrite those apps. Often, a complete rewrite is not possible due to the lack of resources and time, or due to the excessive cost. What are we going to do about those applications? Could we possibly Dockerize them and profit from the benefits introduced by containers?

It turns out we can. In 2017, Docker introduced a program called Modernize Traditional Apps (MTA) to...