How do I run a bash command when Unicorn starts up on rails?

July 20, 2015 521 views
Ruby on Rails DigitalOcean Ubuntu

I'm currently working on an instance with a Rails server with Unicorn on Ubuntu. I've gotten everything running, except for one thing.

There is a gem I'm using called delayed jobs, and it needs to start as a daemon to function correctly whenever the server restarts. The problem is that it seems like the gem has very many different ways of starting, many of which aren't supported with my current version. So, I thought instead of searching through piles of inapplicable docs, I could just start it up with a shell command that I know works.

I'm not using anything like Capistrano - so what would the best way of running a command-line script when Unicorn starts be? I have to run

cd /home/rails/ 
RAILS_ENV=production bin/delayed_job start


1 Answer

Depending on how you are using and starting Unicorn, the most straightforward way to do this would probably be to use a Procfile along with a tool like Foreman. This allows you to define separate tasks to start. E.g.:

web: unicorn -p $PORT -c ./config/unicorn.rb
worker: ./bin/delayed_job start

Then, running foreman start will launch both processes.

Foreman can also be used to generate a set of systemd units or Upstart confs based on the Procfile.

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