What Capistrano::Zen Is?

Capistrano-zen is a collection of capistrano recipes to install and manage various services on production machine powered by Ubuntu. The current tested environment is Ubuntu 12.04LTS.

It provides installation and management recipes for the following service:

• nginx
  • with config templates for rails app
  • static website template
• nodejs
• postgresql
• mysql
• unicorn (integrated with a nginx/railsapp)
• rbenv
• redis

The upcoming recipes include:

• nginx
  • global config template
• shorewall
• vsftp
• php-fpm
• mongodb

capistrano-zen is extracted from the deployment procedure at zenhacks.org for a Rails application so it is designed to work with the structure of a rails application. But most recipes are independent and future development will detach general recipes from a rails application.

What Capistrano::Zen isn't?

capistrano-zen only provides recipes of tasks, it doesn't handle:

• the application dependencies
• the logic of deployment logic
• the server settings and configuration

You will need to declare those in your own capistrano config file such as Capfile or config/deploy.rb.

The gem includes some sample files to start with Capfile-rails-****.sample for various deployment-prove usage.

Installation

Add this line to your application's Gemfile:

gem 'capistrano-zen'

And then execute:

$ bundle

Or install it yourself as:

$ gem install capistrano-zen

Dependencies

capistrano-zen uses python-software-properties to ease ppa source addition. You could install it with use python-software-properties to ease ppa source addition. You could install it from your local machine with

cap deploy:install

Or install it mannually with

sudo apt-get install python-software-properties

Usage

To load a set of recipes, require them in your Capfile with:

require 'capistrano-zen/nginx'

You could verify the load is successful with:

cap -T

Recipes

Here is the recipes included in this gem:

• nginx
  • with config templates for rails app
  • static website template
• nodejs
• postgresql
• mysql
• unicorn (integrated with a nginx/railsapp)
• rbenv

Nginx

Default role: web

Configuration variables: none

Tasks:

• nginx:install installs the lastest release from the ppa ppa:nginx/stable.
• nginx:start/stop/reload maps to sudo service nginx start/stop/reload on the remote machine.
• nginx:setup:unicorn generates a nginx site configuration for a rails app runs with unicorn through unix socket.
• nginx:setup:static generates a nginx site configuration for static sites. require domain, deploy_to and application.

NodeJS

Default role: app

Configuration variables: none

Tasks:

• nodejs:install installs node and npm from the ppa:chris-lea/node.js.

The ppa comes from official wiki.

Redis

Default role: app

Configuration variables: none

Tasks:

• redis:install installs node and npm from the ppa:chris-lea/redis-server.
• redis:start/stop/reload maps to sudo service redis start/stop/reload on the remote machine.

Rbenv

It uses the rbenv installer to create a ruby environment.

Default role: app

Configuration variables:

• ruby_version indicates the ruby version installed.
• rbenv_bootstrap indicates the ubuntu version to install the rbenv bootstrap.

Tasks:

• rbenv:install installs rbenv, setups configuration in ~/.bashrc and installs ruby with ruby_version
• rbenv:patch autoruns a ruby patch to enhance performance. more info

PostgreSQL

Currently, postgresql configuration is tightly attached to a rails application, it depends on the config/database.yml to setup remote server.

Default role: db

Configuration variables:

• config_path the path for the database.yml file, the recipe reads from it to create database and generate remote database.yml. If you are using this recipe out of Rails application, store your configuration in a config/database.yml.
• db_backup_path the path to store database dumps.
• pg_keep_backups the backups versions you want to keep on one remote machine, it defaults to 10.

Tasks:

• pg:install installs postgresql and libpg-dev from ppa:pitti/postgresql.
• pg:reset drops the databases and roles with the same names as in the application.
• pg:init generates roles and databases for the rails application.
• pg:setup generates remote database.yml based on local database.yml's production settings.
• config:db:symlink creates symbolic for the database.yml in the release.
• pg:dump dumps and compresses the application database, store them in the db_backup_path.
• pg:get download the remote dump to local /tmp directory
• pg:put upload the local dumps in /tmp to the remote server
• pg:restore:remote On the remote machine, restores selected dumps from the db_backup_path, it defaults to lastest dump.
• pg:restore:local On the local machine, restores selected dumps from the /tmp, it defaults to lastest dump.
• pg:cleanup cleans up old backups while keep pg_keep_backups numbers of backups.

MySQL

Most capistrano-zen/mysql has similar tasks as Postgresql.

Unicorn

This recipes setup unicorn configuration based on current rails application, and generate a init.d control scripts to manage the service. Default role: app

Configuration variables:

• unicorn_user the user to run unicorn process, default to the same user as remote login user.
• unicorn_group the group to run unicorn process.
• unicorn_pid the path for the unicorn.pid file, default to the current/tmp/pids/unicorn.pid.
• unicorn_config the path to put the unicorn config file, default to shared/config/unicorn.rb.
• unicorn_log the path to put the unicorn log file, default to shared/log/unicorn.log.
• unicorn_workers the number of unicorn workers, default to 4.

Tasks:

• unicorn:setup generate unicorn.rb config file and register service with unicorn_init.
• unicorn:start/stop/restart/upgrade/force-stop maps to remote service unicorn start/stop/restart/upgrade/force-stop. Details is in /tmpls/unicorn_init.rb

Utils

• check:revision autoruns before any deployment tasks. It compares the local and remote master branch head to make sure remote master branch are up-to-date.
• dev_lib:install install libraries on which some gems depend such as nokogiri or paperclip.

Get Started with Capistrano

The wiki page of capistrano has good resources to make you up to speed. Railscasts also has a good coverage for this tool.

TODO

• make configuration rails-less
• add more recipes