As we've seen in this book so far, Spring Boot autoconfigures beans to help us avoid configuring infrastructure and instead focus on coding business requirements. However, sometimes, we may want to know what Spring Boot did (or didn't) do for us.

That's why it has an autoconfiguration report. Essentially, every time a bean is selected based on some conditional check, Spring Boot logs the decision (yea or nay) and offers it to us in many different ways.

The simplest approach is to add --debug to the run configuration. In the following screenshot, we can see how to set it in IntelliJ:

If we launch our app with --debug as a program argument, an autoconfiguration report is printed out to the console:

That's nice, and during certain failure scenarios, the report will print out automatically to help with postmortem...