Capistrano 3, Rails 4, database configuration does not specify adapter - ruby-on-rails

Question

When I start
cap production deploy
it fails like this:
DEBUG [4ee8fa7a] Command: cd /home/deploy/myapp/releases/releases/20131025212110 && (RVM_BIN_PATH=~/.rvm/bin RAILS_ENV= ~/.rvm/bin/myapp_rake assets:precompile )
DEBUG [4ee8fa7a] rake aborted!
DEBUG [4ee8fa7a] database configuration does not specify adapter
You can see that "RAILS_ENV=" is actually empty and I'm wondering why that might be happening? I assume that this is the reason for the latter error that I don't have a database configuration.
The deploy.rb file is below:
set :application, 'myapp'
set :repo_url, 'git#github.com:developer/myapp.git'
set :branch, :master
set :deploy_to, '/home/deploy/myapp/releases'
set :scm, :git
set :devpath, "/home/deploy/myapp_development"
set :user, "deploy"
set :use_sudo, false
set :default_env, { rvm_bin_path: '~/.rvm/bin' }
set :keep_releases, 5
namespace :deploy do
desc 'Restart application'
task :restart do
on roles(:app), in: :sequence, wait: 5 do
# Your restart mechanism here, for example:
within release_path do
execute " bundle exec thin restart -O -C config/thin/production.yml"
end
end
end
after :restart, :clear_cache do
on roles(:web), in: :groups, limit: 3, wait: 10 do
within release_path do
end
end
end
after :finishing, 'deploy:cleanup'
end
Database.yml:
production:
adapter: mysql2
encoding: utf8
database: myapp_production
pool: 5
username: user
password: pass
host: localhost
development:
adapter: mysql2
encoding: utf8
database: myapp_development
pool: 5
username: user
password: pass
host: localhost
The issue is resolved if I add
set :rails_env, "production"
to my deploy.rb, but this looks like hardcoding to me and I'm sure there's a nicer solution.

Answer 1

Edit: Per this pull request, it's now fixed in version 1.1.0 of capistrano-rails.
Per this Github issue, another fix is to edit your Capfile. Comment out these two lines
#require 'capistrano/rails/assets'
#require 'capistrano/rails/migrations'
and put this line in
require 'capistrano/rails'
which will correctly set your RAILS_ENV variable.

Answer 2

Using Cap 3 and capistrano_rails on rails 4 I was getting the same error; in the environment file(s) being deployed, I set
set :stage, :production
set :rails_env, 'production' # even though doc says only need to do this if it's different
Doc here: https://github.com/capistrano/rails

Answer 3

Based on Marc's answer which definitely seems to be the right one,
you can workaround this until it is fixed upstream by adding this to your config/deploy.rb in the "namespace :deploy" block:
desc 'Provision env before assets:precompile'
task :fix_bug_env do
set :rails_env, (fetch(:rails_env) || fetch(:stage))
end
before "deploy:assets:precompile", "deploy:fix_bug_env"
This will force loading the env and provisionning RAILS_ENV before assets:precompile is called.

Answer 4

Seems to be a bug in capistrano-rails.
There is a task (rails.rake) that sets the environment either from rails_env or stage:
namespace :deploy do
before :starting, :set_rails_env do
set :rails_env, (fetch(:rails_env) || fetch(:stage))
end
end
But this task isn't called before i.e. assets:precompile. So this:
namespace :assets do
task :precompile do
on roles :web do
within release_path do
with rails_env: fetch(:rails_env) do
execute :rake, "assets:precompile"
end
end
end
end
end
fails because rails_env is nil if it isn't set explicitly.
If I have the time to dig a little deeper I'll file a bug report.

Answer 5

If you're using passenger, you need to add
rails_env production;
in the in web server's (eg: nginx) .conf where you've specified values for passenger_ruby and passenger_root.

Answer 6

What happens if you add a file:
deploy/production.rb
With this line:
set :stage, :production