Java EE in the container
As it turns out the approach of a layered file system matches Java EE's approach of separating the application from the runtime. Thin deployment artifacts only contain the actual business logic, the part which changes and which is rebuilt each and every time. These artifacts are deployed onto an enterprise container which does not change that often. Docker container images are built step-by-step, layer-by-layer. Building an enterprise application image includes an operating system base image, a Java runtime, an application server and finally the application. If only the application layer changes, only this step will have to be re-executed and retransmitted - all the other layers are touched only once and then cached.
Thin deployment artifacts leverage the advantages of layers since only a matter of kilobytes has to be rebuilt and redistributed, respectively. Therefore, zero-dependency applications is the advisable way of using containers.
As seen in the previous chapter...
