The document discusses using Docker as a development environment. It explains what Docker is, how it works using images and containers, and its benefits like having the same environment locally as production. It then provides examples of using Docker with Ruby on Rails applications, including creating Dockerfiles, using Docker Compose to run multiple services like the app and database, and caching gems with a Docker volume. Links are also included for additional reading on using Docker for development.

2. Bruno de Lima e Silva
Games
Graduate degree in mobile
Parto Humanizado
Crowdmobi, Trakto
Qviky
Coding Dojo

3. Docker as Development
Environment

4. VirtualizationVirtualization What is It?

5. VirtualizationVirtualization Inception

6. VirtualizationVirtualization Why I should use it?

7. VirtualizationVirtualization You don't need to install everything

8. VirtualizationVirtualization Maintenance

9. VirtualizationVirtualization How to do it?

10. ● What?
● “Here it works”, who’s never?
● New team member
● Provision != drean
● Overhead
Same as production environment

11. Docker

12. Docker
“Docker containers wrap up a piece of software in a complete filesystem that
contains everything it needs to run: code, runtime, system tools, system libraries –
anything you can install on a server. This guarantees that it will always run the
same, regardless of the environment it is running in.” - Docker docs
What is it?

13. Docker How it works?
● Docker Hub
● Images
● Build Images
● Share host resources

14. Docker Is it better?

15. Docker How run docker commands
docker run <image> command

16. Docker and Ruby
● Create a ruby file (hello.rb), with this:
● Run it with docker
docker run --rm -v "$(pwd)":/app -w /app ruby:2.2
'ruby hello.rb'
puts ‘The Power of Docker’

17. and Node
● Create a node file (hello.js), with this:
● Run it with docker
Docker
docker run --rm -v "$(pwd)":/app -w /app node
'node hello.js'
console.log(‘Node works too’);

18. ● To link the app we need to start postgres and give it a name
● Then, start the app linking it to postgres
Docker
docker run -d --name db -e
POSTGRES_PASSWORD=123456 postgres
docker run -d -P --link db:dbLink image command
and PostgreSql

19. FROM ruby:2.2
RUN apt-get update && apt-get install -y nodejs --no-
install-recommends && rm -rf /var/lib/apt/lists/*
ENV RAILS_VERSION 4.2.3
RUN gem install rails --version $RAILS_VERSION
WORKDIR $app
ADD . $app
EXPOSE 3000
CMD ["bundle", "exec", "rails", "s", "-b", "0.0.0.0"]
Dockerfile

20. ● Lots of commands
● Lots of params
● I don’t want to remember that all just to run the app
● and that Dockerfile
Docker is getting harder

21. Docker-Compose

22. ● Compose multiple containers
● Just configure it
● Run a single command
Docker-Compose
docker-compose up

23. Sample
web:
build: .
ports:
- "5000:5000"
volumes:
- .:/code
links:
- redis
redis:
image: redis
Docker-Compose

24. Ruby and Rails On Dockercompose

25. db:
image: postgres
ports:
- "5432:5432"
environment:
- POSTGRES_USER=postgres
- POSTGRES_PASS=postgres
Ruby and Rails Start from DB

26. FROM ruby:2.2
RUN apt-get update && apt-get install -y nodejs mysql-client
postgresql-client sqlite3 --no-install-recommends && rm -rf
/var/lib/apt/lists/*
ENV RAILS_VERSION 4.2.3
RUN gem install rails --version $RAILS_VERSION
ENV app /usr/src/app
RUN mkdir $app
WORKDIR $app
ENV BUNDLE_PATH /box
ADD . $app
EXPOSE 3000
CMD ["bundle", "exec", "rails", "s", "-b", "0.0.0.0"]
Ruby and Rails Create app image

27. #!/bin/bash
bundle check || bundle install
bundle exec rails s -b 0.0.0.0 -p 3000
rm -f tmp/pids/server.pid
Ruby and Rails Create app start script

28. box:
image: busybox
volumes:
- /box
Ruby and Rails Add busybox

29. web: &default
build: .
command: ./script/start.sh
volumes:
- .:/usr/src/app
volumes_from:
- box
ports:
- "3000:3000"
links:
- db
Ruby and Rails Create web

30. worker:
<< *default
command: bundle exec rake jobs:work
Ruby and Rails Create workers

31. mailcatcher:
hostname: mailcatcher
image: "schickling/mailcatcher"
command: mailcatcher -f --ip=0.0.0.0
ports:
- "1080:1080"
- "1025:1025"
Ruby and Rails Create MailCatcher

32. https://medium.com/iron-io-blog/why-and-how-to-use-docker-
for-development-a156c1de3b24#.injn4gk15
http://gutocarvalho.net/octopress/2014/05/09/entenda-o-
vagrant/
https://nandovieira.com.br/usando-o-vagrant-como-ambiente-
de-desenvolvimento-no-windows
https://www.thoughtworks.com/pt/insights/blog/puppet-and-
vagrant-how-provision-machines-your-project
Fonts

33. http://www.atlashealth.com/blog/2014/09/persistent-ruby-
gems-docker-container/#.VlJ5ICCrS00
https://medium.com/@fbzga/how-to-cache-bundle-install-with-
docker-7bed453a5800#.b7oq8rnxc
https://github.com/treeder/docker-for-development
Fonts

34. +BrunoDeLimaS
Bruno de Lima
@brunodles
That’s all folksThat’s all folks
+BrunoDeLimaS
Bruno de Lima
@brunodles
https://github.com/Padawan-org/Padawan-Docker