By default, Spring Boot creates a JAR or WAR and that can be run with java -jar application-name.jar. However, it might be desired to run the application as part of the startup of a server (currently tested and supported for Debian and Ubuntu-based systems). For this the Maven or Gradle plugins can be used to create an executable jar.
Problem
How to get an executable JAR so that it can be installed as service on the server environment.
Solution
The Spring Boot Maven and Gradle plugins both have the option to make the created artifact executable. When doing so, the archive also becomes/behaves like a Unix shell script to start/stop a service.
Problem
Instead of creating a JAR file, how to create a WAR file for deployment to a Servlet Container or JEE Container.
Solution
Change the packaging of the application from JAR to WAR and let the Spring Boot application extend the SpringBootServletInitializer so that it can bootstrap itself as a regular application.
Problem
Spring Boot, by default, generates a so-called fat JAR, a JAR with all the dependencies inside it. This has some obvious benefits, as the JAR is fully self-contained. However, the JAR size can grow considerably, and when using multiple applications it might be desired to reuse already downloaded dependencies to reduce the overall footprint.
Solution
When packaging the application, a custom layout can be specified . One such a custom layout is the Thin Launcher. This launcher will result in the dependencies being downloaded before starting the application, instead of the dependencies packaged inside the application.
Using Docker to build and ship containers is common practice nowadays. When using Spring Boot, it is quite easy to wrap that into a Docker container.
Problem
How to run a Spring Boot-based application inside a Docker container.
Solution
Create a Dockerfile and use one of the available Maven Docker plugins to build the Docker container.