Argument error while deploying rails app via capistrano to bluehost - ruby

Question

I have build a sample app using rails and trying to deploy it using capistrano to bluehost.
But I am failing to do so. I followed the instructions mentioned in this http://vasil-y.com/2012/08/21/rails-capistrano-git-bluehost/
This is the contents of my config/deploy.rb:
require 'bundler/capistrano'
set :application, "rails_scaffold"
# BlueHost SSH user
set :user, "username"
# App Domain
set :domain, "example.com"
# We don't need sudo on BlueHost
set :use_sudo, false
# git is our SCM
set :scm, :git
# master is our default git branch
set :branch, "master"
# Use local git repository
set :repository, "#{domain}:/home/#{user}/rails_apps/#{application}"
set :local_repository, "."
# Checkout, compress and send a local copy
set deploy_via, :copy
set deploy_to, "/home/#{user}/rails_apps/#{application}"
# We have all components of the app on the same server
server domain, :app, :web, :db, :primary => true
namespace :deploy do
task :start do ; end
task :stop do ; end
# Touch tmp/restart.txt to tell Phusion Passenger about new version
task :restart, :roles => :app, :except => { :no_release => true } do
run "touch #{File.join(current_path, 'tmp', 'restart.txt')}"
end
end
# Clean-up old releases
after "deploy:restart", "deploy:cleanup"
But when I run the cap deploy:setup command, I get the following error:
/home/swaroop/.rvm/gems/ruby-1.9.3-p362/gems/capistrano-2.14.2/lib/capistrano/configuration/variables.rb:22:in `set': invalid variable `/u/apps/rails_scaffold' (variables must begin with an underscore, or a lower-case letter) (ArgumentError)
It says the application name must begin with an underscore or lowercase alphabets. And my application name looks like it is valid.
What am I doin wrong here?
Thank You

Answer 1

A couple of your set calls have arguments which are not symbols:
set deploy_via, :copy
set deploy_to, "/home/#{user}/rails_apps/#{application}"
Those should be:
set :deploy_via, :copy
set :deploy_to, "/home/#{user}/rails_apps/#{application}"
(Note the colons before deploy_via and deploy_to)
You can see why it might look related to your :application variable if we inspect what is happening in the line containing :deploy_to: it first calls the deploy_to method (since you're missing the colon, it looks like a method call), and deploy_to defaults to "/u/apps/#{application}" in the Capistrano source code:
_cset(:deploy_to) { "/u/apps/#{application}" }
So really, your code is effectively trying trying to run this:
set "/u/apps/#{application}", "/home/#{user}/rails_apps/#{application}"
but "/u/apps/#{application}" is not a valid variable name in Capistrano. Adding colons to those lines should fix it.