Live/Executable War with Jetty Embedded

This project should provide a baseline for those investigating the use of Embedded Jetty from the point of view of a Self Executing WAR file.

The project has 4 main parts:

1. /thewebapp/ - this is the WAR file, the webapp, as it exists in its native format, with normal maven <packaging>war</packaging> and a produced artifact that is just a WAR file that isn't (yet) self-executing.
2. /theserver/ - this is the Embedded Jetty Server jetty.livewar.ServerMain.main(String args[]) which you customize to initialize your Jetty server and its WebApp. This project also is the place where you customize for things like JDBC servers libraries, JNDI, logging, etc. This project produces a uber-jar with all the dependencies needed to run the server. Special care is taken with the maven-shade-plugin to merge META-INF/services/ files.
3. /server-bootstrap/ - this contains 2 small classes that sets up a LiveWarClassLoader from the content in the live WAR and then runs jetty.livewar.ServerMain.main(String args[]) from this new ClassLoader. This project also contains the live META-INF/MANIFEST.MF that the live WAR will need/use
4. /livewar-assembly/ - this is the project that ties together the above 3 projects into a Live/Executable WAR file. The artifacts from from the above 3 projects are unpacked by the maven-assembly-plugin and put into place where they will be most functional (and safe). For example, the server classes from /theserver/ are placed in /WEB-INF/jetty-server/ to make them inaccessible from Web Clients accessing the WAR file.

Note: there are 3 files present in your new assembled WAR file that you should be aware of, as these files can be downloaded by a Web Client as static content if you use this setup.

• /jetty/bootstrap/JettyBootstrap.class
• /jetty/bootstrap/LiveWarClassLoader.class
• /META-INF/MANIFEST.MF

The example project is setup in such a way that information present in these bootstrap files should not reveal private or sensitive information about your Server or its operations. Merely that the Webapp can be started as a Live/Executable WAR file.

Example:

$ mvn clean install
...(snip lots of build output)...
$ java -jar livewar-assembly/target/livewar-example.war 
Using ClassLoader: jetty.bootstrap.LiveWarClassLoader[file:/home/joakim/code/jetty/github-jetty.project/embedded-jetty-live-war/livewar-assembly/target/livewar-example.war]
2021-08-10 15:40:17.905:INFO :oejs.Server:main: jetty-10.0.6; built: 2021-06-29T15:28:56.259Z; git: 37e7731b4b142a882d73974ff3bec78d621bd674; jvm 11.0.12+7
2021-08-10 15:40:18.356:INFO :oejw.StandardDescriptorProcessor:main: NO JSP Support for /, did not find org.eclipse.jetty.jsp.JettyJspServlet
2021-08-10 15:40:18.410:INFO :oejss.DefaultSessionIdManager:main: Session workerName=node0
2021-08-10 15:40:18.431:INFO :oejsh.ContextHandler:main: Started o.e.j.w.WebAppContext@49dc7102{/,file:///tmp/jetty-0_0_0_0-8080-livewar-example_war-_-any-8531005213180319725/webapp/,AVAILABLE}{/home/joakim/code/jetty/github-jetty.project/embedded-jetty-live-war/livewar-assembly/target/livewar-example.war}
2021-08-10 15:40:18.442:INFO :oejs.AbstractConnector:main: Started ServerConnector@289d1c02{HTTP/1.1, (http/1.1)}{0.0.0.0:8080}
2021-08-10 15:40:18.454:INFO :oejs.Server:main: Started Server@275710fc{STARTING}[10.0.6,sto=0] @809ms