The end of the year is often a good time to catch up on some side projects, and this past couple weeks saw me back to focusing on what to do about our collective unfortunate situation. I started by expanding the org.openntf.xsp.jakartaee project to include several additional JEE standards, but then my efforts took a bit of a turn.
Specifically, I thought about Sven Hasselbach's series on dropping Domino's HTTP stack while still keeping API access to Domino data, and decided to take a slightly-different approach. For one, instead of the plucky-but-not-feature-rich Jetty, my eye turned to Open Liberty, the open-source variant of WebSphere Liberty, which in turn is the surprisingly-pleasant trimmed-down counterpart to WebSphere. Using Liberty instead of Jetty means getting a top-tier Java EE runtime, supporting the full Java EE 8 and MicroProfile 2.1 specs, developed by a team chomping at the bit to support all the latest goodies.
Additionally, I decided to try launching Liberty from a Domino plugin, and this bore fruit immediately: with this association, the Liberty runtime is able to fire up sessions and access databases as the Domino server without causing the panic halt that Sven ran into.
So, in short, what this project does is add a fully-capable Java EE server with all the fixings - the latest JEE spec, HTTP/2, Servlet 4, WebSockets, and so forth - running with native access to Domino data alongside a normal server, and with the ability to manage configuration and app deployment via NSFs. Essentially, it's like a second HTTP stack.
I made some good progress in bringing individual JEE technologies to XPages, but I was still constrained by the core capabilities of the XPages runtime, not the least of which was its use of Servlet 2.4, a standard that went obsolete in two-thousand-freaking-five. Every step of the project involves fighting against the whole underlying stack, just to get some niceties that come for free if you start with a modern web container.
Additionally, while Domino has the ability to run Java web applications, this support is similarly limited, providing very few of the standards that make up Java EE and even apparently lacking a JSP compiler set up on the server. It's also, by virtue of necessarily wrapping the app in an OSGi bundle, much fiddlier to develop than a normal WAR file.
And, in a general sense, I'm tired of waiting for this stack to get better. Maybe HCL has grand plans for Java development on Domino in the future - they haven't said. I still doubt it, in part because of the huge amount of work it would entail and in part because I'm not sure that improving XPages would even be strategically wise for them. And say they did improve XPages in a lot of ways people have been clamoring for - WebSockets and whatnot. Would they cover all of the desired features? What about newly-emerging technologies from outside? Their Node.JS strategy makes me think they've thought better of being the vendor of a full-stack web technology.
This route, though, provides a route to making web apps with current standards regardless of what HCL does with XPages. This way, you can work with the entire Java web community at your back, rather than cloistered off with unknown technology. If you want to make an app with Spring, you can, following all of their examples. If you'd rather use PrimeFaces, or just JAX-RS, or JSP, you can do so just as easily. And if your chosen technologies go out of favor, you'll be in the same boat as countless others, and the new preferred choices will be open to you.
Finally, there's just the fact that Java EE 8 is really, really good. The platform made tremendous strides since the bad old days, and developing an app with it is a revitalizing experience.
To set this up, I deliberately chose a very low-integration path: the task in Domino unzips a normal Open Liberty distribution and then runs it using Domino's JVM, just using the default
bin/server script. No embedding, no shared runtime. This way, it doesn't have to fight against any constraints that Domino's environment imposes (such as the fact that both Domino and Liberty want to run an OSGi environment), and it doesn't lead to a situation where a crash in Liberty would bring down Domino's HTTP.
The rest kind of comes along for the ride. Since it's running with the Domino JVM, it already has the trappings needed to use
Notes.jar, so it's really just a matter of using the classes and making sure you run inside a
NotesThread or otherwise initialize and terminate your thread.
Assuming I keep with this project (and I think I have some for-work uses for it, which dramatically increases its odds), I have some ideas for future improvements.
I've added a basic HTTP reverse proxy servlet, and I plan to make it more integrated. The idea there is to allow Liberty to be the primary HTTP entrypoint for Domino, with anything not handled by a web app it's hosting to pass through transparently to Domino.
In time, I aim to add some more integration, such as CrossWorlds and general utilities. I've started by adding in a basic user registry, allowing JEE-standard apps to authenticate against Domino without extra configuration (though it doesn't currently do groups). That could be expanded a good deal - Liberty could read SSO tokens using the C API (or share LTPA as WebSphere normally does), and it'd be nice to have a reasonable method for sharing non-SSO
I set up on the project on GitHub: https://github.com/OpenNTF/openliberty-domino . I think there's some definite promise with this, especially once there are a couple example apps that could show off the possibilities.