Some Spring Boot thoughts

[Tom Zeller]

I find Spring Boot interesting, as it seems to address some relevant
issues with the testbed as well as the v3 AACLI.

(a) Spring Boot supports externalized configuration with
self-referential properties, e.g. :
 idp.properties:
  idp.home=/opt/idp
  idp.keystore.path=${idp.home}/creds/idp.jks

(b) The Spring Boot Maven plugin creates executable WARs and JARs.

(c) The Spring Boot Loader allows executable WARs and JARs to load
nested JARs as dependencies.

(d) Spring Boot Starters are (Maven) plugins which can embed Tomcat or Jetty.

(e) Spring Boot Actuator endpoints like /health, /metrics, and /trace
seem useful.


For the v3 AACLI, I thought we might skip a "traditional" application layout :

 bin/aacli.sh
 bin/aacli.bat
 lib/idp-attribute-cli.jar
 lib/...dependencies..

and replace it with

 java -jar <something>.jar

which loads dependencies from idp.war, for example. I guess I like the
idea of not maintaing shell or batch files in lieu of Java.


The Spring Framework 4.0 announcement mentions Spring Boot fairly
early, and I have heard a Pivotal employee talk about how Spring Boot
is being rapidly accepted internally.

I played with Spring Boot briefly, one issue I encountered is it wants
to be the parent in a POM, which I think might be okay for an
application like an installer, but not for idp-* modules.

Just some thoughts. In the last few days I looked for a way to support
self-referential properties and loading dependencies from a WAR, and
it seems like Spring Boot might help, hence this message.