pry_into_warbler

Quick hack to make an interactive pry shell running inside a JRuby jar created via warbler

What is this again?

I was trying to figure out some oddities when accessing file paths inside a JRuby jar and wanted to be able to run an interactive pry shell from inside the jar in order to experiment with accessing files in the jar and compare to running the same commands when running the same code but not compiled into a jar. I wrote this quick hack and am publishing it in case anyone else cares - and so I can find it in the future.

HOWTO

• clone the repo
• run bundle install # note that this assumes rvm and has .ruby-version you might want to hack at
• run warble jar to build the jar
• run java -jar pry_into_warbler.jar to execute in the jar
• OR run ruby lib/pry_into_warbler.rb to execute not from the jar

You can see the small amount of code in lib/pry_into_warbler.rb. It is just aimed at starting pry interactively and exposing a path to the 'public' path where some trivial content is located.

When run in the jar one might do:

[1] pry(#<PryIntoWarbler>)> rebase('base1.txt')
=> "uri:classloader:/pry_into_warbler/public/base1.txt"
[2] pry(#<PryIntoWarbler>)> File.exist? rebase('base1.txt')
=> true

When run outside the jar one might do:

[1] pry(#<PryIntoWarbler>)> rebase('base1.txt')
=> "/Users/jband/hacks/pry_into_warbler/public/base1.txt"
[2] pry(#<PryIntoWarbler>)> File.exist? rebase('base1.txt')
=> true

NOTES

I know nearly nothing about warbler. We use it for our product. But, other people set that up. I just did this hack to try to emulate that setup we use. It may or may not be a reasonable way to do this.

The 'pry' startup when run in the jar complains a bit. I think that is just due to it not being able to find the file source because the config options I'm using compile the ruby code to classfiles. Or, maybe not.