Capistrano recipes for Rails

We deploy a lot of Rails applications and our developers have to solve similar problems each time during the deployment: how to run workers, how to generate crontab, how to precompile assets faster and so on. This collection of recipes helps us to solve them.

Recipe use:

foreman + foreman_export_runitu to generate runit scripts with the Procfile
whenever to generate crontab
nginx as proxy server

It also consider that you use rbenv on the server.

Installation

gem 'capistrano_rails_recipes', :require => false

Capfile example:

require "capistrano_rails_recipes/capistrano"

set :repository, "[email protected]:..."
set :application, "my_application"
set :user, 'deploy'
set :branch, 'master'
set :deploy_to, "/path/to/app"
set :use_sudo, false

server 'web.example.com', :web, :app, :worker, :crontab
role :db, 'web.example.com', primary: true

OR

task :production do
  role  :web,     "web.example.com"
  role  :app,     "app.example.com"
  role  :crontab, "app.example.com"
  role, :db,      "db.example.com", :primary => true
  role, :worker,  "workers.example.com"
end

task :staging do
  server "stage.example.com", :web, :app, :crontab, :db, :worker
end

As you can see, we use use roles to bind the tasks, and there are some additions to roles and additional roles:

deploy:setup creates all necessary folders and symlinks to files: config/nginx.conf -> /opt/nginx/conf/sites-enabled/my_application creates deploy_to/shared/config folder creates deploy_to/services folder copies config/database.example.yml -> shared/config/database.yml

Run deploy:setup before your first deploy. See below how to configure services.

web compiles assets if content of app/assets was changed since last deploy (add FORCE=1 to force the assets compilation)

app all files from shared/config is being symlinked to current/config like:

shared/config/database.yml            -> current/config/database.yml
shared/config/settings/production.yml -> current/config/settings/production.yml

crontab generates crontab with whenever gem, only if the content of config/schedule.rb was changed (add FORCE=1 to force the crontab generation)

db run migrations only if db/migrate was changed (add FORCE=1 to force migrations or SKIP_MIGRATION=1 to skip them)

worker Procfile exports runit configs to deploy_to/application/services

On deploy:restart runit workers is being restarted.

You can use some extra cap tasks:

rails:console to launch rails console on remote server
rails:dbconsole to launch rails dbconsole on remote server
login to open SSH session under user deploy and switch catalog to Capistrano's current_path

Important

To run succesfully together with system wide rbenv, all you tasks in Procfile must be started with rbenv exec

Configuring services

To run services just create Procfile in root of your app.

Procfile example:

sidekiq: rbenv exec bundle exec sidekiq -L sidekiq.log
web: rbenv exec bundle exec unicorn -c config/unicorn.rb -E production

Also you need to configure runit to monitor deploy_to/services folder.

Nginx config file example for Unicorn

upstream unicorn_my_application {
  server unix:/tmp/unicorn.my_application.sock fail_timeout=0;
}

server {
  listen 80;
  server_name web.example.com;
  root deploy_to/current/public;

  location ^~ /assets/ {
    gzip_static on;
    expires max;
    add_header Cache-Control public;
  }

  try_files $uri/index.html $uri @unicorn;
  location @unicorn {
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_redirect off;
    proxy_pass http://unicorn_my_application;
  }

  error_page 500 502 503 504 /500.html;
  client_max_body_size 4G;
  keepalive_timeout 10;
}

Change deploy_to and my_application to your actual values.

Unicorn config file example

root = "deploy_to/current"
working_directory root
pid "#{root}/tmp/pids/unicorn.pid"
stderr_path "#{root}/log/unicorn.log"
stdout_path "#{root}/log/unicorn.log"

listen "/tmp/unicorn.my_application.sock"
worker_processes 5
timeout 30

Change deploy_to and my_application to your actual values.

Capistrano

Default variables:

logger.level                   = Capistrano::Logger::DEBUG
default_run_options[:pty]      = true
ssh_options[:forward_agent]    = true
set :bundle_cmd,                 "rbenv exec bundle"
set :bundle_flags,               "--deployment --quiet --binstubs --shebang ruby-local-exec"
set :rake,                       -> { "#{bundle_cmd} exec rake" }
set :keep_releases,              7
set :scm,                        "git"
set :user,                       "deploy"
set :deploy_via,                 :unshared_remote_cache
set :copy_exclude,               [".git"]
set :repository_cache,           -> { "#{deploy_to}/shared/#{application}.git" }
set :normalize_asset_timestamps, false

Bonus track

To enable silent mode, add ENV['CAP_SILENT_MODE'] before the require 'capistrano_evrone_recipes/capistrano' in your Capfile

silent mode