Using guard with foreman

I’ve been playing with Ruby quite a bit recently and I like the way a custom-looking DSL can be created from the same source language.

This means I’ve converted a lot of my tools (e.g. Makefiles) into Rakefiles and I’ve just found foreman which can manage multiple subprocesses and combine their output into a nice looking coloured console result. This is typically used to manage web processes (server, task runner, development database etc.) and is required by heroku.

I was using this technique with a simple Procfile for managing my thesis. I have two tasks running: latexmk which manages the latex compiling, and guard which manages the python plotting.

I added these to the Procfile as such

latex: latexmk -pvc --pdf Thesis
plotting: bundle exec guard

This would cause both processes to hang, which I couldn’t explain. I then thought that guard is interactive: it has an interface for managing specific tasks or getting info about the processes running. I searched through the guard help to find the --no-interactions flag and this solved my problem. My new complete Procfile is now

latex: latexmk -pvc --pdf Thesis
plotting: bundle exec guard --no-interactions