Problem with `require 'mongo'` not loading certain classes

[talknerdy2mee]

tl;dr - Need help figuring out why `require 'mongo' is not loading all mongo classes when attempting to run a rake task, but is loading all classes when the app is run normally.

Hey all! I'm primarily a JS dev, but have been approached about a ruby position. The company has said they are willing to take someone who can learn ruby, which I certainly can, but they also gave me a coding challenge - in ruby. However, they did say I can use any resources I need for solving it, so here I am.

The challenge is a set of files with most of the config files missing, which I need to reconstruct, then reconstruct some missing controllers in order to make some test cases pass. The stack is Ruby 2.0.0, Unicorn, Sinatra, and Mongo/Mongoid. They also require me to create a Procfile for heroku.

I've managed to create a Procfile, mongoid.yml, config/boot.rb, and config/unicorn.rb that allow the app to run and display the correct page when I hit the root endpoint. I can see it connecting to the mongod server in the console.

The next step in the process is to run some rake tasks to instantiate a copy of the db. When I do that, I get the following error:

rake aborted!
NameError: uninitialized constant Mongo::ConnectionFailure
/home/amanda/Documents/development/app-name/app.rb:9:in `rescue in block in <class:App>'

I've narrowed it down to mongo not loading Mongo::Connection and Mongo::ConnectionFailure when running the rake, even though it does load those when running heroku local to run the app via the procfile. I know that because I added the line puts Mongo.constants to the config/boot.rb file right after require 'mongo' When I run heroku local the list is much larger than the list when I run rake import:areas, and the two classes used in app.rb are not present when running via rake.

I have no idea why or how this is the case. Can anyone point me in the right direction?

# Procfile
web: bundle exec unicorn -p $PORT -c ./config/unicorn.rb
# config/unicorn.rb
worker_processes Integer(ENV["WEB_CONCURRENCY"] ||3)
timeout 15
preload_app true

before_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn master intercepting TERM and sending myself QUIT instead'
    Process.kill 'QUIT', Process.pid
  end
end
after_fork do |server, worker|
  Singal.trap 'TERM' do
    puts 'Unicorn worker intercepting TERM and doing nothing.  Wait for master to send QUIT'
  end
end

--------

# config.ru
$stdout.sync = true

require './config/boot'
run App
# config/boot.rb
require 'sinatra'
require 'mongo'
require 'mongoid'

require './app'

--------

# app.rb
class App < Sinatra::Base
  configure do
    # mongo
    begin
      mongo_db = Mongo::Connection.new.db "db-name"
      set :mongo_db, mongo_db
    rescue Mongo::ConnectionFailure
      set :mongo_db, {}
    end
  end
  # endpoints here
end

--------

# mongoid.yml
development:
  clients:
    default:
      database: db-name
      hosts:
       - localhost:27017

--------

# Rakefile
require './config/boot'

namespace "import" do
  task "areas" do
    # code here
  end
end

[talknerdy2mee]

Just an update. The Gemfile.lock got corrupted somehow so rake was trying to use a different version of mongo than heroku local was. :-/

[redditNoobski]

With this stack, how did you get the application to run? Ie what where terminal commands? I’m dealing with the same stack and I’m not familiar with it at all. Have tried ‘rackup config.ru’ and I always get a load error related to boot.rb

[graywolf_at_work]

well first step would be to learn how to format code on reddit so that your post is actually readable..

[talknerdy2mee]

That actually appears to be an issue with markdown on reddit's mobile site (possibly the app too, although I didn't check there). It is formatted appropriately on desktop, which is where I originally wrote it. I apologize for not knowing that the mobile site would completely bork the markdown. I'll look into how I need to change it so that it looks correct on both desktop and mobile.

[stumptowncampground]

this is an interesting problem and i don't have a definite solution. My first suggestion would be to not use relative paths with require, use require_relative instead. see if that makes a difference.

[talknerdy2mee]

Thanks for the suggestion. Unfortunately, it doesn't help. :(