This project is a drop in replacement for fpm that you don't have to gem install and can even run without a Ruby
installation. It combines JRuby, fpm, and some shell
scripting to create a single executable binary for running fpm with nothing more than just a JVM installed. It also
incorporates some hackery to speed up the unreasonably slow startup time for JRuby when there are additional gem paths
to search. fpm is an awesome tool, and we should all be grateful for its
existence.
It's a drop in replacement for fpm, so you can download the latest version of jfpm, include it in your $PATH, and
set it executable all in one go:
sudo curl -o /usr/local/bin/fpm -L "https://github.com/rholder/jfpm/releases/download/v1.3.3.1/jfpm" && \
sudo chmod +x /usr/local/bin/fpmI'm setting the versioning such that it's the target fpm version followed by an additional patch number in case I
update anything in between major releases.
First, if you create a fatjar and just drop all of the gems for a project into the root of an extracted
jruby-complete.jar then it will happily run for you (see here).
However, it will also be 10x slower than if you run your application with an external ruby-gems.jar rolled from a pile
of downloaded gems (as sort of described here). Fine, so
let's just shove the ruby-gems.jar file into the final fatjar and extract it at runtime.
This was really more of a proof of concept to see if I could crank out a JRuby-standalone binary that didn't need quite
such a long time to bootstrap. Some future development might be to profile the exact order of resource loading being
done for the built-in files and try to optimize those lookups away in an additional cache. A previous iteration monkey
patched the built-in org.jruby.runtime.load.LoadService class to inject a cache for reading .rb files contained in
the external gem archive, but as of JRuby 1.7.18, it doesn't add any additional speedup so it's gone in favor of
sweeping up some of the complexity.
##License
The jfpm project is released under version 2.0 of the
Apache License. Portions of modified JRuby source are released under
EPL 1.0 as described here. fpm
is MIT-style licensed.