One way to modernize a monolithic application running within a virtual machine is to use the same code base but change the form factor to a container. A containerized application is managed much differently from a virtual machine and comes with its own strengths and weaknesses. A monolithic application moved to a container can take advantage of the portability that containers provide such as portability, immutability, and start up time but requires a change to the operational processes to manage the application.

Before and After Modernization

Converting a monolithic application into a container can be accomplished in a couple of ways. The first is to repackage the application as a container using tools such as the Tanzu Build Service, Cloud Native Buildpacks, or creating a Dockerfile for the application. This method would be analogous to building a new application as a container after the application code has been written.

An alternative to building a container from the source code would be to take a running virtual machine and convert it to a container. VMware Cloud customers have access to Application Transformer for VMware Tanzu, which can be used to convert running virtual machines into a containerized image, that can later be deployed. This is particularly effective for WebSphere and Tomcat applications due to Application Transformer’s capabilities.