Run Rails commands outside of console

Question

With my large application, the Rails console takes a while to load up. Is there a way to single commands more easily?

I'd also like to be able to automate stuff, and echo "query" | rails console isn't a great way to do things.

Thoughts?

EDIT: What about a long-running process that I can ping queries to whenever I have need?

Solution 1

There are two main ways to run commands outside console:

1. Rake task which depends on :environment

2. rails runner (previously script/runner), eg:

   $ rails runner "query"
   

Both are pretty well documented on the rails guide: https://guides.rubyonrails.org/command_line.html#bin-rails-runner

btw: both of these methods will still take the same time as a console to fire up, but they are useful for non-interative tasks.

Solution 2

Just pipe it in:

echo 'puts Article.count' | bundle exec rails c

It should now be a lot faster than when then the question was originally asked, because of Spring. It's not immediate, but still a lot faster than spinning up the whole app. Use this for the fast lane, it should run in under a second (assuming your required command is fast):

echo 'puts Article.count' | spring rails c

If you really want a single long-running process, you could easily do it by creating a controller action that simply runs whatever you POST to it, then send commands to it using curl behind an alias. The action would of course be completely insecure and should be triple-guarded against running anywhere near production, but it would be easy to setup.

Comments

[Andrew Marshall]

I'm curious what your use case for this is, as it seems that there's probably a better solution.

[tekknolagi]

I'm using Geckoboard to grab stats from a running application, using a JSON feed I'm setting up with these queries... am I doing it completely wrong?

[Andrew Marshall]

It would probably make more sense to just build this code right into your app and grab the data over HTTP. If it's sensitive info, then require some sort of authorization, e.g. an API key with the request.

[tekknolagi]

I, unfortunately, don't have much experience at all with Rails. I'd have no idea how to build a query like User.all.count into a page and grab the results. How should I do that?

[Andrew Marshall]

Well if you're trying to make a JSON feed, then you would just generate it as JSON. There are plenty of resources for how to send a JSON response using Rails.

[tekknolagi]

How would I add it to the app though?

[Andrew Marshall]

If you don't know how to do that, then perhaps you need to work through a Rails tutorial or the Rails Guides. It's a rather broad question.

[Joshua Pinter]

Genius!! Btw, if you're trying to return a "fail exit code" you use abort. For example: echo 'abort' | bundle exec rails c && echo 'Success!' will not show Success! in the console where as echo 'exit' | bundle exec rails c && echo 'Success!' will show Success!.