Dockerizing a rails app and developing in it. Start with an existing rails app (or rails new), build an image, start it, make and see changes to your running app

1. Rails in Docker
Dockerizing and developing
Andrew Klotz
@klotzandrew

2. What is docker?
- Package code, with environment, and dependencies
- Docker images
- Containers run images

3. What you need to install
● docker
● docker-compose
● docker-machine
● https://docs.docker.com/docker-for-mac

4. docker-machine
● eval $(docker-machine env default)
● docker-machine ls

5. Dockerized rails
Ruby container
● Ruby
● Build ourselves
Database container
● PostgreSQL
● Use official image

6. Docker image for rails
● Rails new or existing app
● Add a Dockerfile (touch Dockerfile)

7. ● Connect to containerized db in config/database.yml

8. Database
● official postgres image
● docker run --name db postgres
● docker ps

9. Docker orchestration
- vim docker-compose.yml
- docker-compose up

10. Check it out!
● visit (docker-machine ip):3000
● docker ps
● see live code changes in the container
● run commands with a container
○ docker exec -it dockerrails_web_1 rails test
○ docker exec -it dockerrails_web_1 bash

11. Recap
● vim Dockerfile
● vim database.yml
● vim docker-compose.yml
● docker-compose up