In this article I will show you how to set up a CentOS 7 development machine for the Rails development. I won't cover the actual CentOS install here, but I will cover everything that comes after. This article will cover using rbenv and ruby-build for ruby version management. Note that there are some prerequisites. You must have root access to the machine that you are using, or you must be able to use the sudo command as we will need to install a few system packages.

Step 1: Update your system.

It's important to ensure your system is up to date. To do this, run the yum update command like so:

$ yum update -y

Now we need to install a few dependencies that will allow us to install rbenv, ruby-build, ruby, and mini_racer. Run the command below to install these:

$ sudo yum install git make gcc gcc-c++ zlib-devel sqlite-devel readline-devel bzip2 openssl-devel

Step 2: Install rbenv and ruby-build

The installation of rbenv is simple. Run the following commands below:

git clone ~/.rbenv
cd ~/.rbenv && src/configure && make -C src && cd ~
echo 'export PATH="~/.rbenv/bin:$PATH"' >> ~/.bash_profile
echo 'eval "$(rbenv init -)"' >> ~/.bash_profile

Next, we install ruby-build. This one is simple as well:

git clone ~/.rbenv/plugins/ruby-build

Now, at this point, let's reboot. This will allow any package/kernel updates to take effect, and once we log back in we will be ready to go:

sudo reboot

Step 3: Install Ruby

After the system reboots, it's time to install Ruby and Rails. As of this writing, the latest version of Ruby is version 2.5.1, so I'll use that for demonstration purposes, but you can install whatever version you want. To install, simply run the command below, replacing 2.5.1 with the version of your choice.

rbenv install 2.5.1

Assuming you don't have any problems, Ruby 2.5.1, should now be installed, however, we need to make it our active version of Ruby. To do this, run the command below:

 rbenv global 2.5.1

Now let's verify that Ruby is correctly installed. Run the command below and you should get output similar to below:

ruby --version
ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux]

What if you have an application that needs another version of Ruby? For instance, you have a legacy application that only runs on 2.3 due to compatibility issues. With rbenv, you can simply run the following commands to do this:

$ rbenv install 2.3.7
$ cd /path/to/your/app
$ rbenv local 2.3.7

If you run a ruby --version while in your application's path, you should get output similar to below:

ruby 2.3.7p456 (2018-03-28 revision 63024) [x86-64-linux]

Note that this will also create a .ruby-version file that you can check into source control, so other developers using rbenv can use the same version. There are other uses for this file as well that will be covered in another article.

Step 4: Configure the firewall

Chances are firewalld is enabled. If this is the case, you'll want to add a port for port 3000 if you wish to access the development server from outside the machine, for instance, in the case of VMs. To do this, simply run:

sudo firewall-cmd --zone=public --permanent --add-port 3000/tcp --reload

Installing Database Clients and Servers

In this section we will show you how to install MySQL and PostgreSQL clients and servers. Note that MySQL is actually MariaDB on CentOS 7, which is a fork. However it works perfectly fine for our needs.

MySQL (MariaDB)

CentOS 7 uses the MariaDB fork of MySQL. This should cause no issues should you decide to go with this approach.

Installation of the Client

To install the client and gem, simply run the commands below:

sudo yum install mariadb-devel
gem install mysql2

The commands should complete without error. You may then add the gem 'mysql2' line to your Gemfile.

Installation of the Server

If you need the server, simply run the commands below, first, install the mariadb-server: bash sudo yum install mariadb-server

Next, enable it as a service and start it:

sudo systemctl enable mariadb
sudo systemctl start mariadb

Finally, to finish setup, run mysql_secure_installation, you will be prompted with the prompts below, respond appropriately (Note: I skipped the text here and only included the prompts):

Enter current password for root (enter for none): (push enter)
Set root password [Y/n] (push enter, defaults to capital letter, in this case Y for yes)
New password: (enter a good root password)
Re-enter new password: (confirm your new password)
Remove anonymous users? [Y/n] (push enter)
Remove test database and access to it? [Y/n] (push enter)
Reload privilege tables now? [Y/n] (push enter)

MariaDB is now set up and available for use.


Installing PostgreSQL is pretty easy as well.

Installing the Client

Simply run the commands below to install the client and the gem:

sudo yum install postgresql-devel
gem install pg

The commands should complete without error. You may now use the gem 'pg' line in your Gemfile.

Installing the Server

Installing the server is pretty easy as well, simply run the commands below:

sudo yum install postgresql-server
sudo postgresql-setup initdb
sudo systemctl enable postgresql
sudo systemctl start postgresql

PostgreSQL should now be available for use. Have any further thoughts for expansion on this article? Find any problems with these steps? Be sure to leave a comment below! Thanks for reading!