[RAILS] How to create an application server on an EC2 instance on AWS

Introduction

AWS is an abbreviation for Amazon Web Servises, which is a cloud server service provided by Amazon. We will output what we have learned in order to improve our understanding of AWS.

This flow

• Install Unicorn in your application
• Create an application server on an instance created with EC2 on AWS
• Production environment settings
• Launch application

It is assumed that you have created an instance.

• If you don't know how to create an instance, please see here. "How to build a virtual server on AWS" https://qiita.com/daisuke30x/items/91307c94e8f5a702a42f

Install Unicorn in your application

① Install Unicorn in your own application

Add the following description to the Gemfile in the application.

Gemfile

group :production do
    gem 'unicorn', '5.4.1'
end

• If you have already deployed on Heroku, I think there is a rails_12factor gem, but please delete or comment out that gem.

Terminal

% bundle install

② Unicorn settings

Create unicorn.rb in your application's config. Then, make the following settings.

config/unicorn.rb

#Put the directory where the application code on the server is installed in a variable
app_path = File.expand_path('../../', __FILE__)

#Determine application server performance
worker_processes 1

#Specify the directory where the application is installed
working_directory app_path

#Specify the location of the files required to start Unicorn
pid "#{app_path}/tmp/pids/unicorn.pid"

#Specify the port number
listen 3000

#Specify a file to log errors
stderr_path "#{app_path}/log/unicorn.stderr.log"

#Specify the file to record the normal log
stdout_path "#{app_path}/log/unicorn.stdout.log"

#Set maximum time to wait for Rails application response
timeout 60

#The following is an applied setting, so the explanation is omitted.

preload_app true
GC.respond_to?(:copy_on_write_friendly=) && GC.copy_on_write_friendly = true

check_client_connection false

run_once = true

before_fork do |server, worker|
  defined?(ActiveRecord::Base) &&
    ActiveRecord::Base.connection.disconnect!

  if run_once
    run_once = false # prevent from firing again
  end

  old_pid = "#{server.config[:pid]}.oldbin"
  if File.exist?(old_pid) && server.pid != old_pid
    begin
      sig = (worker.nr + 1) >= server.worker_processes ? :QUIT : :TTOU
      Process.kill(sig, File.read(old_pid).to_i)
    rescue Errno::ENOENT, Errno::ESRCH => e
      logger.error e
    end
  end
end

after_fork do |_server, _worker|
  defined?(ActiveRecord::Base) && ActiveRecord::Base.establish_connection
end

Push it to the remote repository and reflect it.

Create an application server on an instance created with EC2 on AWS

③ Install the application on the instance

Terminal

Log in to your instance
% ssh -i key pair name.pem ec2-user@<Public IP>

In the instance/var/www/Creating a directory
[instance]$ sudo mkdir /var/www/

Ec2 permissions on the created www directory-Granted to user
[instance]$ sudo chown ec2-user /var/www/

Go to www directory
[instance]$ cd /var/www/

#Clone application from GitHub
[Instance www]$ git clone <HTTPS URL obtained from the Code button of the application you want to deploy on GitHub>

④ Install Gem

• Increase memory with Swap file before installing Gem (to prevent error due to insufficient memory when installing Gem)

Terminal

Move to your home directory in your instance
[Instance www]$ cd ~

Swap file settings
[instance]$ sudo dd if=/dev/zero of=/swapfile1 bs=1M count=512
[instance]$ sudo chmod 600 /swapfile1
[instance]$ sudo mkswap /swapfile1
[instance]$ sudo swapon /swapfile1
[instance]$ sudo sh - -c 'echo "/swapfile1  none        swap    sw              0   0" >> /etc/fstab'

• Install Gem

Terminal

Go to the application directory in your instance
[instance]$ cd /var/www/<Application name>

Install bundler(The version of bundler is "command" in the terminal+Create another tab with "T" and "bundler" in the newly created tab-You can check it by executing "v")
[instance<Application name>]$ gem install bundler -v <bundler version>

Install Gem
[instance<Application name>]$ bundle install

Production environment settings

⑤ Environment variable settings

For security reasons, database passwords etc. are not uploaded to GitHub. Such information is set using "environment variables".

• Creating secret_key_base

What is secret_key_base

A character string used to encrypt cookies. Required for running Rails applications in production.

Terminal

[instance<Application name>]$ rake secret
=> secret_key_The character string that becomes the base is displayed

Move to your home directory within the instance
[instance<Application name>]$　cd ~

/etc/Edit environment
[instance]$ sudo vim /etc/environment

Type "i" to enter input mode

Enter the password of the root user of the configured database
DATABASE_PASSWORD='Database root user password'
SECRET_KEY_BASE='The secret created earlier_key_base'

* If you are using AWS S3, enter the following (enter the value referring to the CSV file downloaded when setting S3)
AWS_ACCESS_KEY_ID='Copy the value of Access key ID in the CSV file here'
AWS_SECRET_ACCESS_KEY='Copy the value of Secret access key in the CSV file here'

* If you have introduced Basic authentication, enter the following (enter the set user name and password)
BASIC_AUTH_USER='Set user name'
BASIC_AUTH_PASSWORD='Password set'

「:Save as "wq"

Log out of the instance and log in again for the environment variables to take effect
[instance]$ exit
% ssh -i key pair name.pem ec2-user@<Public IP>

Checking environment variables
[Instance re]$ env
=>OK when the settings set above are displayed.

⑥ Release the port to the security group

In the AWS Management Console, add "Port 3000" and "Source 0.0.0.0/0" of "Custom TCP" to the inbound rule of the security group of the instance.

⑦ Change Rails application settings

You must also set the environment variables you set in your instance above in your application.

：config/database.yml

production:
  <<: *default
  database:(* Do not edit here)
  username: root
  password: <%= ENV['DATABASE_PASSWORD'] %>
  socket: /var/lib/mysql/mysql.sock

After changing the settings, push to GitHub.

Then let the instance reflect the changes in your application.

Terminal

Move to the application directory within the instance
[instance]$ cd /var/www/<Application name>

Reflect application setting changes
[instance<Application name>]$ git pull origin master

Launch application

⑧ Create database (if database server exists in instance)

Please refer to here for how to create a database server https://qiita.com/daisuke30x/items/7501d724a0727ad9f2e4

Terminal

Creating a database
[instance<Application name>]$ rails db:create RAILS_ENV=production
[instance<Application name>]$ rails db:migrate RAILS_ENV=production

Start database
[instance<Application name>] $ sudo systemctl start maradb

RAILS_ENV = production is an option to specify the production environment

⑨ Start application

• Launch application

Terminal

[instance<Application name>]$ bundle exec unicorn_rails -c config/unicorn.rb -E production -D

• Compiling asset files

Compile your application's asset files (CSS, JavaScript, images, etc.). This is a necessary task in a production environment.

Terminal

[instance<Application name>]$ rails assets:precompile RAILS_ENV=production

• Restart application

Terminal

Check the process
[instance<Application name>]$ ps aux | grep unicorn
=>The second number from the left is the process ID

Process stop
[instance<Application name>]$ kill <unicorn_Rails master process ID>

Launch the application again
[instance<Application name>]$ RAILS_SERVE_STATIC_FILES=1 unicorn_rails -c config/unicorn.rb -E production -D

"RAILS_SERVE_STATIC_FILES = 1" is the role that specifies that the compiled asset file can be found.

** Enter "http: // : 3000 /" or "http: // : 3000 /" in the browser, and if the application is displayed, it is successful. ** **

Finally

We hope that this post will help beginners review.