rails 5.1.4 console in production doesn't find models - ruby-on-rails-5

Question

I think I got a configuration issue with my rails setup in production.
I've got a puma working fine without any issues (connecting to db, loading models etc) and previously was able to use the console (I've encountered this [bug][https://github.com/rails/rails/issues/19256] but worked around it by filling in the database.yml)
When I try to open the console to perform little operations, none of my model classes are found.
✗ bundle exec rails console production
Running via Spring preloader in process 18313
Loading production environment (Rails 5.1.4)
irb(main):001:0> User.count
NameError: uninitialized constant User
from (irb):1
irb(main):002:0>
Similar questions on SO recommend to run ActiveRecord::Base.subclasses and eventually Rails.application.eager_load!
When I do try to run Rails.application.eager_load! I get uninitializaed constant error
irb(main):005:0> Rails.application.eager_load!
NameError: uninitialized constant ApplicationController
Did you mean? ApplicationCable
from app/controllers/accounts_controller.rb:1:in `<top (required)>'
from (irb):5
So I guess my console is now somehow lost and hasn't loaded the project source correctly.
How can I troubleshoot this situation ?
edit 2018-02-15 : I connected my workstation to the prod environment to use the console. This worked at first, the console was behaving correctly. After a couple times the same issues appeared. After doing spring stop I was able again to user my local workstation to open a console in prod.
Interesting fact : this never happens in dev environment, although spring had an app running in this environment.
It turns out spring is also running in prod, although the spring gem is only in dev group. (see below)
Gemfile
source 'https://rubygems.org'
git_source(:github) do |repo_name|
repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
"https://github.com/#{repo_name}.git"
end
gem 'rails', '~> 5.1.4'
gem 'puma', '~> 3.7'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'therubyracer', platforms: :ruby
gem 'coffee-rails', '~> 4.2'
gem 'jbuilder', '~> 2.5'
group :development, :test do
gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
gem 'capybara', '~> 2.13'
gem 'selenium-webdriver'
gem 'rails-erd', require: false, group: :development
end
group :development do
gem 'web-console', '>= 3.3.0'
gem 'listen', '>= 3.0.5', '< 3.2'
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
gem 'pry'
gem 'pry-byebug'
end
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
gem 'devise'
gem 'devise-i18n'
gem 'cancancan', '~> 2.0'
gem 'rolify'
gem 'redis', '~> 3.2'
group :production do
gem "sidekiq"
gem "sentry-raven"
end
gem 'pg'
gem "paperclip", "~> 5.0.0"
gem 'i18n-country-translations'
gem 'rails-i18n', '~> 5.0.0'
gem 'i18n_alchemy'
gem 'wicked_pdf'
gem 'wkhtmltopdf-binary'

Answer 1

If you deployed through Docker make sure using -ti prefix in running command like:
docker exec -ti 4d318d505e9f rails c production