Compile Assets With Capistrano

Hi there!

I have a project with lots of compiled assets: sprites, stylesheets and javascripts. This causes big pain in our deployment process due to overall instability in nodejs world. I actually cannot figure out why my asset-builder just fails without any reason on production server.

By the way, compiling assets on server-side is quite a bad idea just because developer has less control on production server than on his own machine. That’s why I think it’s better to compile the assets on developer side.

The process

Let’s start from explaining how assets are compiled here in my project:

# Install npm dependencies
npm install
# Install bower dependencies. Have no idea why we need both of them. It's our frontend guy choice.
node_modules/.bin/bower install
# Actualy compilation
node_modules/.bin/broccoli build tmp

And then we need to copy compiled assets under web folder.

Capistrano tasks

Ok, let’s create a bit of capistano tasks:

namespace :assets do
  set :tmp_dir, '.capistrano/assets'
  set :npm, 'npm'
  set :bower, 'node_modules/.bin/bower'
  set :broccoli, 'node_modules/.bin/broccoli'

  #desc Build assets locally
  task :build_local do
    run_locally do
        invoke "assets:cleanup"
        execute fetch(:npm), 'install'
        execute fetch(:bower), 'install'
        execute fetch(:broccoli), 'build', fetch(:tmp_dir)

  #desc Copy all the assets to our :web servers
  task :copy do
    on roles(:web) do
      Dir["#{fetch(:tmp_dir)}/webpub/*"].each do |f|
        upload! f, "#{release_path}/webpub/", recursive: true

  #desc Clean up all the stuff left from compilation
  task :cleanup do
    run_locally do
      execute 'rm', '-rf', fetch(:tmp_dir)

Capistrano workflow

And now we need to inject these tasks into deployment process:

before "deploy:starting", "assets:build_local"
before "deploy:publishing", "assets:copy"
before "deploy:finished", "assets:cleanup"

Actually, that’s all we need to do.

Alex Panshin avatar
About Alex Panshin
Software Engineer from Russia. Interested in PHP, Scala, microservices and Big/Fast Data stuff.
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