Deploying Rails app with Capistrano 3

In the lifetime of every application the time comes for it to be presented to everyone. That’s why we have to put our application on a special server which is designed for this purpose. In one word, we need to deploy our application. In this post you will see how to deploy app with Capistrano 3.

Capistrano is a great developers tool that is used to automatically deploy projects to remote server.

Add Capistrano 3 to Rails app

I will assume you already have a server set up and an application ready to be deployed remotely.

We will use gem ‘capistrano-rails’, so we need to add this gems to Gemfile:

group :development do
  gem 'capistrano', '~> 3.5'
  gem 'capistrano-rails', '~> 1.1.6'
end

and install gems with $ bundle install.

Initialize Capistrano

Then run the following command to create configuration files:

$ bundle exec cap install

This command creates all the necessary configuration files and directory structure with two stages, staging and production:

Capfile
config/deploy.rb
config/deploy/production.rb
config/deploy/staging.rb
lib/capistrano/tasks

Require needed gems in Capfile

Open the Capfile and add or uncomment this lines:

require 'capistrano/setup'
require 'capistrano/deploy'
require 'capistrano/bundler'
require 'capistrano/rails/assets'
require 'capistrano/rails/migrations'
Dir.glob('lib/capistrano/tasks/*.rake').each { |r| import r }

Add capistrano-rbenv gem

The capistrano-rbenv gem provides rbenv support for Capistrano 3.

Add this line to the Gemfile:

group :development do
  gem 'capistrano', '~> 3.5'
  gem 'capistrano-rails', '~> 1.1.6'
  gem 'capistrano-rbenv', '~> 2.0', require: false
end

And require this gem in Capfile require 'capistrano/rbenv'.

Add capistrano-passenger gem

The capistrano-passenger gem adds a task to restart your application after deployment via Capistrano 3.

group :development do
  ...
  gem 'capistrano-rbenv', '~> 2.0', require: false
  gem 'capistrano-passenger', '~> 0.2.0'
end

And require this gem in Capfile require 'capistrano/passenger'

+ set all needed variables, this is the variant with two servers (_staging and production_) and with user created on server (_server setup is theme for different post_)

set :application, 'app-name'   # application name
set :deploy_user, 'user-name'   # name of user who is set on server
set :repo_url, 'git@github.com:nickname/repo_name.git'   # your repository url from github
set :branch, ENV.fetch('BRANCH', 'master')   # branch which you want to deploy from

set the path where you want to find your app on server, starting from server’s root

set :deploy_to, -> { "/path/to/app/#{fetch(:rails_env)}-#{fetch(:application)}" }

• set config files, Capistrano uses a folder called shared to manage files and directories that should persist across releases

  set :linked_files, fetch(:linked_files, []).push('config/database.yml', 'config/secrets.yml')
  set :linked_dirs, fetch(:linked_dirs, []).push('log', 'tmp/pids', 'tmp/cache', 'tmp/sockets', 'vendor/bundle', 'public/system')
  

• next, set ruby version, we use `gem ‘capistrano-rbenv’` for this setup

  set :rbenv_type, :user
  set :rbenv_ruby, '2.2.2'
  

• after that, set option for restarting your application after deployment with gem 'capistrano-passenger'

  set :passenger_restart_with_touch, true
  

• here you can put all kinds of rake tasks for different needs that you can run every time when you deploy your application.

  namespace :deploy do
    desc "Description of task"
    task :name_of_task do
        # do something
    end
  end
  

Capistrano’s server settings

You need to tell Capistrano where to find your server.
This is an example of server’s settings for application where everything is on same machine (application, server, database).

• In config/deploy/staging set:

  server 'your.staging.server.com', user: fetch(:deploy_user), roles: %w{app db web}
  

• and set rails environment

  set :rails_env, 'staging'
  

Also set the same configuration for production server.

In `config/deploy/production` add:

server 'your.production.server.com', user: fetch(:deploy_user), roles: %w{app db web}
set :rails_env, 'production'

Deploy your application

Just run deploy task:

bundle exec cap staging deploy

or

bundle exec cap production deploy

and that is it, your app is live and you can visit it on server’s name url, in our example case your.staging.server.com.

Note: you can find complete documentation on Capistrano site.

Have a nice day!

 

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