Capistrano Symfony Parameters

parameters.rake

desc "create empty parameters"
task :parameters_empty do
	on roles(:all) do
		if  not test("[ -f #{shared_path}/app/config/parameters.yml ]")
			upload! StringIO.new('---'), "#{shared_path}/app/config/parameters.yml"
		end
	end
end

desc "configure parameters with dist values if not defined"
task :parameters do
	on roles(:all) do
		distParameters = YAML::load(capture("cat #{release_path}/app/config/parameters.yml.dist"))
		if test("[ -f #{shared_path}/app/config/parameters.yml ]")
			parameters = YAML::load(capture("cat #{shared_path}/app/config/parameters.yml"))
			if parameters
				distParameters['parameters'].each do |k,v|
					if parameters['parameters'][k].nil? && parameters['parameters'].fetch(k, false) == false
						set :distParameter, ask(k, v)
						parameters['parameters'][k] = fetch(:distParameter)
					end
				end
			else
				parameters = YAML::load(capture("cat #{release_path}/app/config/parameters.yml.dist"))
				distParameters['parameters'].each do |k,v|
					set :distParameter, ask(k, v)
					parameters['parameters'][k] = fetch(:distParameter)
				end
			end
		else
			parameters = YAML::load(capture("cat #{release_path}/app/config/parameters.yml.dist"))
			distParameters['parameters'].each do |k,v|
				set :distParameter, ask(k, v)
				parameters['parameters'][k] = fetch(:distParameter)
			end
		end
		upload! StringIO.new(parameters.to_yaml), "#{shared_path}/app/config/parameters.yml"
	end
end

desc "configure all parameters"
task :parameters_configure do
	on roles(:all) do
		distParameters = YAML::load(capture("cat #{release_path}/app/config/parameters.yml.dist"))
		if test("[ -f #{shared_path}/app/config/parameters.yml ]")
			parameters = YAML::load(capture("cat #{shared_path}/app/config/parameters.yml"))
			if parameters
				distParameters['parameters'].each do |k,v|
					if parameters['parameters'][k].nil? && parameters['parameters'].fetch(k, false) == false
						set :distParameter, ask(k, v)
						parameters['parameters'][k] = fetch(:distParameter)
					else
						set :distParameter, ask(k, parameters['parameters'][k])
						parameters['parameters'][k] = fetch(:distParameter)
					end
				end
			else
				parameters = YAML::load(capture("cat #{release_path}/app/config/parameters.yml.dist"))
				distParameters['parameters'].each do |k,v|
					set :distParameter, ask(k, v)
					parameters['parameters'][k] = fetch(:distParameter)
				end
			end
		else
			parameters = YAML::load(capture("cat #{release_path}/app/config/parameters.yml.dist"))
			distParameters['parameters'].each do |k,v|
				set :distParameter, ask(k, v)
				parameters['parameters'][k] = fetch(:distParameter)
			end
		end
		upload! StringIO.new(parameters.to_yaml), "#{shared_path}/app/config/parameters.yml"
	end
end

This will sync parameters.yml with parameters.yml.dist, providing two tasks parameters which will prompt for missing parameters and parameters_configure which will allow you to change all the parameters.

To add to your scripts you will want to add:

before 'deploy:check:linked_files', 'parameters_empty'
before 'deploy:symlink:shared', 'parameters'

Thanks, @carlcraig! That's exactly what I was looking for.

Maybe parameters.yml should not be copied to a shared folder? Each release could have different set of parameters.