Selective compilation

before_compile_assets.rb

last_revision = run "cat #{current_path}/REVISION"
assets_modified =  run "git diff --name-only #{last_revision} | grep '/assets/' | wc -l"

if assets_modified.output.to_i > 0
  info "#{assets_modified} asset files changed detected. Compiling assets"
  `cd #{release_path} && PATH=#{release_path}/ey_bundler_binstubs:$PATH #{environment} rake assets:precompile RAILS_GROUPS=assets"`
else
  info "No asset changes detected. Copying assets from previous"

  current = shared_path + '/assets'
  last_asset_path = shared_path + '/last_assets'

  run <<-COMMAND
if [ -d #{current_path} ]; then
  rm -rf #{last_asset_path} && mkdir #{last_asset_path} && mv #{current} #{last_asset_path} && mkdir -p #{current};
else
  mkdir -p #{current} #{last_asset_path};
fi;
ln -nfs #{current} #{last_asset_path} #{current_path + '/public'}
  COMMAND
end