Docker with Rails - right development environment

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Working as a team, you are constantly faced with the problem of supporting the project infrastructure on developers machines. When there is a small team (2-4 people), this problem is solved quickly.

The question is what to do when the number of developers increases, when the product grows or when there are remote developers? The solution is very simple and tech - to use the Docker for local development.

With the local development we want: to work quickly and efficiently with the project, with a minimum of time to dev ops, use your favorite code editor (for me it’s VIM), do not worry about installing of additional tools and packages. All these gives us Docker with its simplicity and convenience.

Let’s consider a simple project (Rails application), which one we want to develop on the local machine, but do not want to set: ruby, gems, nginx, postrgesql.

First we need to set up a virtual box, docker, docker-composer, docker-machine:

• brew install wget
• brew install virtualbox
• brew install docker
• brew install docker-compose
• brew install docker-machine
• brew install dnsmasq

The next step is to synchronize the configuration of our virtual machine and a local folder for code:

• sudo sh -c 'echo "\"/Users\" 192.168.99.100 -alldirs -mapall=501:20" > /etc/exports'
• sudo sh -c 'echo "nameserver 192.168.99.100" > /etc/resolver/dev'
• sudo nfsd restart

Now let's create the docker machine (call it lab):

• docker-machine create --driver virtualbox --virtualbox-memory 4096 --virtualbox-disk-size 20480 --virtualbox-cpu-count 4 lab
• docker-machine start lab
• docker-machine env lab
• eval $(docker-machine env lab)
• curl https://gist.githubusercontent.com/OpakAlex/db44c598c166c93b561a/raw/da8f171ab84c03a1e149fbc3be7bf3feeaf5f1df/setup-docker-machine.sh | bash
• Copy now your project in the folder ~ /
• Create Dockerfile in the project and docker-compose.yml

Example files: Dockerfile, compose

Let’s try to start:

• docker-compose build
• docker-compose run web bundle install
• docker-compose run web rake db:create
• docker-compose up

And the last magic is to open the browser: testapp.dev and see our app!

It works virtually, so it is very easy to add support of any service, as well as to migrate from one database to another, the team will not have problems with the installation of local packages and their administration. Make life of your team easier with Docker.

If you have problems running nginx, you need to make a few commands:

• https://github.com/OpakAlex/rails-docker-nginx-example/blob/master/bin/install.rb

Working Example: https://github.com/OpakAlex/rails-docker-nginx-example