Install Ruby On Rails on
Ubuntu 19.04 Disco Dingo

Configuring Git

We'll be using Git for our version control system so we're going to set it up to match our Github account. If you don't already have a Github account, make sure to register. It will come in handy for the future.

Replace my name and email address in the following steps with the ones you used for your Github account.

git config --global color.ui true
git config --global user.name "YOUR NAME"
git config --global user.email "[email protected]"
ssh-keygen -t rsa -b 4096 -C "[email protected]"

The next step is to take the newly generated SSH key and add it to your Github account. You want to copy and paste the output of the following command and paste it here.

cat ~/.ssh/id_rsa.pub

Once you've done this, you can check and see if it worked:

ssh -T [email protected]

You should get a message like this:

Hi excid3! You've successfully authenticated, but GitHub does not provide shell access.

Installing Rails

Choose the version of Rails you want to install:

gem install rails -v 6.0.2.2

If you're using rbenv, you'll need to run the following command to make the rails executable available:

rbenv rehash

Now that you've installed Rails, you can run the rails -v command to make sure you have everything installed correctly:

rails -v
# Rails 6.0.2.2

If you get a different result for some reason, it means your environment may not be setup properly.

Setting Up MySQL

Rails ships with sqlite3 as the default database. Chances are you won't want to use it because it's stored as a simple file on disk. You'll probably want something more robust like MySQL or PostgreSQL.

There is a lot of documentation on both, so you can just pick one that seems like you'll be more comfortable with. If you're coming from PHP, you may already be familiar with MySQL. If you're new to databases, I'd suggest skipping to setting up PostgreSQL.

You can install MySQL server and client from the packages in the Ubuntu repository. As part of the installation process, you'll set the password for the root user. This information will go into your Rails app's database.yml file in the future.

sudo apt-get install mysql-server mysql-client libmysqlclient-dev

Installing the libmysqlclient-dev gives you the necessary files to compile the mysql2 gem which is what Rails will use to connect to MySQL when you setup your Rails app.

When you're finished, you can skip to the Final Steps.

Setting Up PostgreSQL

For PostgreSQL, we're going to add a new repository to easily install a recent version of Postgres.

sudo apt install postgresql-11 libpq-dev

The postgres installation doesn't setup a user for you, so you'll need to follow these steps to create a user with permission to create databases. Feel free to replace chris with your username.

sudo -u postgres createuser chris -s

# If you would like to set a password for the user, you can do the following
sudo -u postgres psql
postgres=# \password chris

Final Steps

And now for the moment of truth. Let's create your first Rails application:

#### If you want to use SQLite (not recommended)
rails new myapp

#### If you want to use MySQL
rails new myapp -d mysql

#### If you want to use Postgres
# Note that this will expect a postgres user with the same username
# as your app, you may need to edit config/database.yml to match the
# user you created earlier
rails new myapp -d postgresql

# Move into the application directory
cd myapp

# If you setup MySQL or Postgres with a username/password, modify the
# config/database.yml file to contain the username/password that you specified

# Create the database
rake db:create

rails server

You can now visit http://localhost:3000 to view your new website!

Now that you've got your machine setup, it's time to start building some Rails applications.

If you received an error that said Access denied for user 'root'@'localhost' (using password: NO) then you need to update your config/database.yml file to match the database username and password.