How to Deploy Rails App With Capistrano?

Being a software developer it’s a part of routine job to perform on assigned tasks, do the required changes, build new features and make it live to production. All of these stuff such as taking pull from branch, migrating, bundling and seeding is a tedious process. Almost every other developer is in need of a tool to ease things up.

If you are looking for automating deployment, then one tool is already there called Capistrano. I am writing this technical blog to help you understand that how to deploy a Rails application to AWS using Capistrano.

For better understanding, consider that you are using the Passenger + Nginx + PostgreSQL. Passenger is the application server, Nginx is the reverse proxy, and PostgreSQL is the database server.

So, before you proceed for deployment it is must to have an existing application and one server. i.e. We will be using AWS Ec2 instance. For more details on how to create EC2 Instance please visit, https://www.bacancytechnology.com/blog/aws-ec2-how-to-create-ec2-instance-from-scratch”

After, creating instance you have to setup environment that is able to run Rails app for the listed below steps :

Step 1: Setup the Server

- sudo apt-get update
- sudo apt-get install build-essential libssl-dev libyaml-dev libreadline-dev openssl curl git-core zlib1g-dev bison libxml2-dev libxslt1-dev libcurl4-openssl-dev nodejs libsqlite3-dev sqlite3

Note: Based on Database used on your rails app you have to install that in this server, for example, Postgres or Mysql

Install RVM & Ruby

curl -sSL https://get.rvm.io | bash -s -- --path /home/ubuntu/.rvm	 	 	
export rvm_path=/home/ubuntu/.rvm	 	 	
rvm install 2.4.2

Install Git and add SSH

Step 2: Let’s start by configuring each module one by one

Configuring Passenger & Capistrano

Please add below gems in your Gem file

group :development do
 gem 'capistrano', require: false
 gem 'capistrano-rvm', require: false
 gem 'capistrano-rails', require: false
 gem 'capistrano-bundler', require: false
 gem 'capistrano-passenger', require: false
end

Note: For more details on GEM please visit : https://github.com/capistrano/capistrano

Step 3: Install bundle and generate Capistrano config files

-After adding Gem into Gemfile run ‘bundle install’

– Now after successful installation for all gem it’s time to configure Capistrano,

- cap install cap install STAGES=production

Above command will generate a list of file for configuring Capistrano such as config/deploy.rb and config/deploy/production.rb

Step 4: Configure Capistrano Files

For the first file, we have to configure Capfile to paste below lines into your Capfile. Search Capfile in your rails App root directory.

# Load DSL and set up stages
			require "capistrano/setup"
			require "Capistrano/deploy"

			require "capistrano/scm/git"
			install_plugin Capistrano::SCM::Git

			require 'capistrano/setup'
			require 'Capistrano/deploy'

			require 'Capistrano/rails'
			require 'Capistrano/bundler'
			require 'Capistrano/rvm'
			require 'Capistrano/passenger'
			require "whenever/Capistrano"

		Dir.glob("lib/capistrano/tasks/*.rake").each { |r| import r }

Note : this file is already added in your cap file you just have to uncomment it or replace all with the above code.

Step 5: Configure deploy.rb

# config valid only for the current version of Capistrano

lock "3.10.2"

		server '54.88.139.244', port: 22, roles: [:web, :app, :db], primary: true

		set :repo_url, '< repo url >'
		set :application, < app_name >'
		set :user, 'ubuntu' #server user

		set :rvm_bin_path, "$HOME/bin"
		set :rvm_ruby_version, '[email protected]_name'

		# Don't change these unless you know what you're doing
		set: pty, true
		set :use_sudo, false
		set :rails_env, "production"
		set :stage, :production
		set :deploy_via, :remote_cache
		set :deploy_to, "/home/#{fetch(:user)}/apps/#{fetch(:application)}"

		set :ssh_options, { forward_agent: true, user: fetch(:user), keys: %w(~/.ssh/id_rsa) }

		set :branch, :< branch name >

		namespace: deploy do

		desc 'Initial Deploy'
		task: initial do
		on roles(:app) do
		before 'deploy: restart'
		invoke 'deploy'
		end
		end

		set :linked_files, %w{config/database.yml}

		after :finishing, :compile_assets
		after :finishing, :cleanup
		after :finishing, :restart
		end

– In deploy.rb change following things

Set your ip
Set your repository
Set application name
Set user
Set rvm path as per your installation
Set deploy_to path
Set linked_file (It’s secret files that is confidential for your application. We need to create symbolic on a server for that files)

Step 6: Create a Symbolic link

– You have to create a symbolic link for storing Credential like database.yml and .env

– For that Create directory in this structure app_name/shared/config/database.yml
e.g. sudo vi /home/ubuntu/apps/blog__app/shared/config/database.yml

Step 7: Install and configure passenger-Nginx

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 561F9B9CAC40B2F7

– Edit below file

sudo vi /etc/apt/sources.list.d/passenger.list

– Add below line in that file

deb https://oss-binaries.phusionpassenger,com/apt/passenger xenial main

– Save that file and exit

And run below command in terminal

- sudo chown root: /etc/apt/sources.list.d/passenger.list
- sudo chown ubuntu: /etc/apt/sources.list.d/passenger.list
- sudo chmod 600 /etc/apt/sources.list.d/passenger.list

- sudo apt-get update

- sudo apt-get install nginx-extras passenger

After installation done open Nginx configuration file and uncomment below the line.

# Uncomment it if you installed passenger or passenger-enterprise include /etc/nginx/passenger.conf;

By running below command

- sudo vi /etc/nginx/nginx.conf

user www-data;
worker_processes auto;
pid /run/nginx.pid;

events {
worker_connections 768;
# multi_accept on;
}

http {
# Basic Settings

sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;

include /etc/nginx/mime.types;
default_type application/octet-stream;

access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;

# Gzip Settings

gzip on;
gzip_disable "msie6";

# Uncomment it if you installed passenger or passenger-enterprise
include /etc/nginx/passenger.conf;

# Virtual Host Configs

include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}

- sudo vi /etc/nginx/passenger.conf

Check passenger.conf that passenger ruby is there, if your file contains below two line your good to go

passenger_root /usr/lib/ruby/vendor_ruby/phusion_passenger/locations.ini;

passenger_ruby /usr/bin/passenger_free_ruby;

Step 8: Create or edit nginx site-enable/site-available, as described below,

- sudo vi /etc/nginx/sites-enabled/default

server {
      listen 80 default_server;
      server_name < IP >;
      #server_name < hostname >;
      passenger_enabled on;
      passenger_app_env production;
      passenger_app_group_name production;
      root /home/ubuntu/apps/app_name/current/public;
    }

Note: Please change the root path according to your application location.

At Last just run command :

cap production deploy

and restart Nginx server using below command

sudo service nginx restart

Related Article: Why You Should Deploy Your Rails App with Capistrano