Capistrano is a tool for automating deployment of web applications. It connects to servers over SSH and runs tasks like code deployment, database migrations, and asset precompilation. It uses a Ruby DSL to define tasks and roles for different servers. Capistrano comes with default tasks but can also be customized. It is commonly used for deploying Ruby on Rails apps but works with other stacks as well. The Capistrano gem generates files needed to get started, and tasks can be tailored for specific apps or server environments.

1. CAPISTRANO
for non-Rubyists

2. who we are
Dimitris Tsironis
Founder at Geembo, UI designer & huge geek, who
loves good design and french fries, as much as good
indentation in a stylesheet. Follow him @tsironakos
and @geemboHQ
Dr. John Pagonis
Dr. John Pagonis is onto something with Missum
these days. You can follow him at @JohnPagonis
and @MissumApp

3. WHAT’S THE PROBLEM?
deploys can be a real mess
mistakes could happen very easily
you don’t mess with the production
you’re actually delaying bug fixes, new features etc.

4. one-click deploys!
(well, almost)

5. is a language agnostic tool for remote application
administration tasks
provisioning of infrastructure better handled
with other tools, eg. Chef, Puppet, Babushka
it fits well with deploying web-apps
heavily used by Rails community
it’s for sysadmins and devops guys

6. how it works
under the bonnet

7. philosophy
it runs on your computer
connects to the server over ssh
there is no Capistrano server or sth like that
automates the tasks you would manually do
with command-line

8. philosophy part ii
uses a Ruby-based DSL for task automation
there are already ready-to-use tasks
cap shell offers an interactive prompt for adhoc
commands
cap shell sessions are cached and can be reused

9. built-in tasks
It ships with plenty of stuff, by default

10. ready-to-use recipes
You can find plenty on Github
https://github.com/nesquena/cap-recipes
Ruby setup & RubyGems management
Apache & Phusion Passenger
Aptitude management
MongoDB
and much more!

11. custom tasks
Tailor-made Capistrano tasks are easy.
It’s all Ruby and Rake-like tasks, after all.

12. how to set it up
prepare for the battle

13. set it up
you need a Capfile in the root of the project
then, you can execute capistrano tasks anywhere in
your project’s folder, by running:
cap <task name>

14. rails-less deploy example

15. capify
Capify is a file generator for your project
usually used with Rails project but it works with other projects
in general, it can be enhanced to work with other structures

16. capify
One command to generate the files
Files you need
Capfile - basic Capistrano file in root of the project
config/deploy.rb - here’s where you write custom tasks

17. production or staging
config/deploy/production.rb
config/deploy/staging.rb

18. roles
allow you to write capistrano tasks that only apply to
certain servers
then you can do something like this

19. configuration example
config/deploy.rb

20. custom tasks example
config/deploy.rb

21. RAILS-specific magic
tasks for Ruby on Rails only

22. asset precompile
PROBLEM
Asset precompile can be slow.
It could take several minutes that
we could use to make a coffee
or watch some cats gifs

23. asset precompile
solution
Skip precompile, if it isn’t necessary
“The ability to destroy
a planet is insignificant
next to the power of Git”
--a tech-savvy Darth Vader

24. rails-specific magic
config/deploy.rb
Source: StackOverflow of course!

25. RESOURCES
Deploying with Capistrano - Github Help
https://help.github.com/articles/deploying-with-capistrano
Capistrano Wiki
https://github.com/capistrano/capistrano/wiki
Capistrano Multistage extension
https://github.com/capistrano/capistrano/wiki/2.x-Multistage-Extension
Capistrano Handbook - still immature
https://github.com/leehambley/capistrano-handbook/blob/master/
index.markdown
Capistrano Google Group
http://groups.google.com/group/capistrano

26. thank you!
@JohnPagonis
@tsironakos
@geemboHQ