Deploying to AWS EC2 using Capistrano

This guide walks through the process of creating a cloud server using Amazon Web Services, configuring it to run as a deployment server and setting up a deployment workflow using Capistrano

Create an AWS account (you will be eligible for one year free-tier). Navigate to the EC2 Dashboard in Singapore region
In local machine Terminal enter the following command and copy the result. If you do not have a default SSH key, follow the steps here to generate one with the identity id_rsa
```
  cat ~/.ssh/id_rsa.pub
```
From the AWS EC2 dashboard click ‘Key Pairs’, then ‘Import Key Pairs’. Specify the name id_rsa and paste the key you just copied from your local machine. Then click ‘Import’.
Click on Instances in the sidebar and 'Launch Instance'. Select Ubuntu Server 14.04 LTS (HVM), SSD Volume Type - ami-25c00c46
Select General purpose: t2.micro and click 'Review and Launch'
At the review page, click 'Edit Security Groups'.
Create a security group named merchant and Add Rule HTTP to allow incoming HTTP connections on port 80 (see image):
Click 'Review and Launch' to go back to the review page. Click 'Launch'
To associate an SSH key to enable secure remote login, select 'Choose an existing key pair' and select id_rsa
Check the check-box and click 'Launch Instances'. You will be brought to the post-launch page
Click on View Instances to be taken back to the AWS EC2 console to view your new instance. After a short initialization time (about 30 seconds), the instance should have passed status checks
When Capistrano is run on the local machine, it will connect to your EC2 server via SSH to remotely pull down the latest code from GitHub and deploy it into production. To enable this, we need to allow the local machine to forward SSH requests
On local machine, open the file ~/.ssh/config and add the following (NOTE: replace the IP address with that of your EC2 instance)
```
  Host 52.77.234.2
   ForwardAgent yes
```

Next, you need to add your local private key to the ssh-agent - reference here

  mhan@Mingdings-MacBook-Air:~$ eval "$(ssh-agent -s)"
  Agent pid 29576

  mhan@Mingdings-MacBook-Air:~$ ssh-add ~/.ssh/id_rsa
  Identity added: /Users/mhan/.ssh/id_rsa (/Users/mhan/.ssh/id_rsa)

  The authenticity of host '52.77.234.2 (52.77.234.2)' can't be established.
  RSA key fingerprint is fc:ed:63:62:dc:48:e7:a8:c7:0e:20:75:3f:48:76:55.
  Are you sure you want to continue connecting (yes/no)? yes
  Warning: Permanently added '52.77.234.2' (RSA) to the list of known hosts.
  Welcome to Ubuntu 14.04.3 LTS (GNU/Linux 3.13.0-74-generic x86_64)

   * Documentation:  https://help.ubuntu.com/

    System information as of Sat Feb 20 11:21:36 UTC 2016

    System load: 0.16             Memory usage: 5%   Processes:       81
    Usage of /:  9.9% of 7.74GB   Swap usage:   0%   Users logged in: 0

    Graph this data and manage this system at:
      https://landscape.canonical.com/

    Get cloud support with Ubuntu Advantage Cloud Guest:
      http://www.ubuntu.com/business/services/cloud

  0 packages can be updated.
  0 updates are security updates.

    The programs included with the Ubuntu system are free software;
    the exact distribution terms for each program are described in the
    individual files in /usr/share/doc/*/copyright.

    Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
    applicable law.

    ubuntu@ip-172-30-0-195:~$

2. Setup EC2 instance with Ruby and RVM

Step by step instructions to setup your EC2 server for deploying a Rails application. Reference here

  ubuntu@ip-172-30-0-195:~$ pwd
  /home/ubuntu

Switch to root user privileges to update system and install Ubuntu packages

  # from ubuntu@ip-172-30-0-195:~$
  sudo -s

  # from root@ip-172-30-0-195:~#
  apt-get update
  apt-get -y upgrade
  apt-get -y install build-essential libmagickcore-dev imagemagick libmagickwand-dev libxml2-dev libxslt1-dev git-core nginx redis-server curl nodejs htop

  # Set Rails environment
  echo "RAILS_ENV=production" >> /etc/environment

  # Add a gemrc file to ubuntu user
  echo -e "verbose: true\nbulk_threshold: 1000\ninstall: --no-ri --no-rdoc --env-shebang\nupdate: --no-ri --no-rdoc --env-shebang" > /home/ubuntu/.gemrc
  chmod 644 /home/ubuntu/.gemrc
  chown ubuntu:ubuntu /home/ubuntu/.gemrc
  exit
  ubuntu@ip-172-30-0-195:~$

Install RVM and Ruby - reference here

  \curl -sSL https://get.rvm.io | bash -s
  source ~/.rvm/scripts/rvm

  rvm install 2.2.2
  rvm use 2.2.2 --default
  # Using /home/ubuntu/.rvm/gems/ruby-2.2.2

  ruby -v
  # ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-linux]

  gem install bundler
  # Fetching: bundler-1.11.2.gem (100%)
  # Successfully installed bundler-1.11.2
  # 1 gem installed

3. Install and configure Nginx, Passenger and PostGreSQL

Switch to root user privileges

  # from ubuntu@ip-172-30-0-195:~$
  sudo -s

Install Git + Passenger + Nginx

  apt-get install -y git

  apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 561F9B9CAC40B2F7
  apt-get install -y apt-transport-https ca-certificates
  sh -c 'echo deb https://oss-binaries.phusionpassenger.com/apt/passenger trusty main > /etc/apt/sources.list.d/passenger.list'

  # update ubuntu sources
  apt-get update
  apt-get install -y nginx-extras passenger

Enable the Passenger Nginx module

  vi /etc/nginx/nginx.conf

  # uncomment the following lines
  # passenger_root /usr/lib/ruby/vendor_ruby/phusion_passenger/locations.ini;
  # passenger_ruby /usr/bin/passenger_free_ruby;

Restart Nginx and validate the installation

  service nginx restart
  passenger-config validate-install

  # * Checking whether this Passenger install is in PATH... ✓
  # * Checking whether there are no other Passenger installations... ✓

  # Everything looks good. :-)
  exit
  ubuntu@ip-172-30-0-195:~$

To ensure Nginx knows where to find the application code after we deploy, create a new conf file in /etc/nginx/sites-enabled with the application name merchant
```
  cd /etc/nginx/sites-enabled
  sudo vi merchant.conf
```

Add the following Nginx server configuration

  server {
    listen 80;
    server_name 52.77.234.2; #replace with your server ip or domain

    # specify the application's 'public' directory 
    root /home/ubuntu/apps/merchant/current/public;

    # Turn on Passenger
    passenger_enabled on;
    passenger_ruby /home/ubuntu/.rvm/gems/ruby-2.2.2/wrappers/ruby;
  }

As mentioned in the reference, the last line passenger_ruby should be replaced by the path to the correct Ruby interpreter to use passenger-config about ruby-command
Restart Nginx
```
  sudo service nginx restart
```

Setting Up PostgreSQL

  sh -c "echo 'deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main' > /etc/apt/sources.list.d/pgdg.list"
  wget --quiet -O - http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | sudo apt-key add -

  sudo apt-get update
  sudo apt-get install -y postgresql-common
  sudo apt-get install -y postgresql-9.3 libpq-dev

Test that pg gem can install properly with native extensions

  gem install pg -v '0.18.3'

  # Fetching: pg-0.18.3.gem (100%)
  # Building native extensions.  This could take a while...
  # Successfully installed pg-0.18.3
  # 1 gem installed

Configure PostgreSQL to accept all connections

  ls /etc/postgresql
  sudo vim /etc/postgresql/9.3/main/pg_hba.conf 

  # change the following lines to METHOD 'trust', and save
  # =======================
  # TYPE  DATABASE        USER            ADDRESS                 METHOD

  # "local" is for Unix domain socket connections only
  # local   all             all                                     trust
  # IPv4 local connections:
  # host    all             all             127.0.0.1/32            trust
  # IPv6 local connections:
  # host    all             all             ::1/128                 trust

  sudo service postgresql reload
  sudo -u postgres createuser ubuntu -s

4. Setup Capistrano on local machine

Switch to a new code branch: git checkout -b capistrano

Update Gemfile for development environment and bundle install

  group :development do
    gem 'capistrano', '~> 3.4'  
    gem 'capistrano-rails', '~> 1.1'
    gem 'capistrano-bundler'
    gem 'capistrano-passenger'
    gem 'capistrano-rvm'
  end

  # Capistrano 3.1 has some breaking changes. Please check the CHANGELOG: http://goo.gl/SxB0lr
  # If you're upgrading Capistrano from 2.x, we recommend to read the upgrade guide: http://goo.gl/4536kB
  # The `deploy:restart` hook for passenger applications is now in a separate gem called capistrano-passenger.  Just add it to your Gemfile and require it in your Capfile.

Enable your project to use Capistrano

  bundle exec cap install STAGES=production

  # mkdir -p config/deploy
  # create config/deploy.rb
  # create config/deploy/production.rb
  # mkdir -p lib/capistrano/tasks
  # create Capfile
  # Capified

In the Capfile uncomment these lines:

  # Capfile
  require 'capistrano/rvm'
  require 'capistrano/bundler'
  require 'capistrano/rails/assets'
  require 'capistrano/rails/migrations'
  require 'capistrano/passenger'

Specify Capistrano configuration for deployment instance

  # config/deploy.rb
  set :application, 'merchant'
  set :repo_url, '[email protected]:hanmd82/merchant.git'
  ask :branch, `git rev-parse --abbrev-ref HEAD`.chomp
  set :deploy_to, '/home/ubuntu/apps/merchant'
  set :scm, :git
  set :format, :pretty
  set :log_level, :info
  set :pty, true
  set :linked_dirs, fetch(:linked_dirs, []).push('log', 'tmp/pids', 'tmp/cache', 'tmp/sockets', 'vendor/bundle', 'public/system')
  set :keep_releases, 5

Configure Capistrano to get app repo from Github and deploy

  # config/deploy/production.rb
  server '52.77.234.2', user: 'ubuntu', roles: %w{web app db}
  set :ssh_options, { forward_agent: true }

5. Deploy the app with Capistrano

Ensure that these two gems are in your Gemfile and bundle install
```
  gem 'therubyracer', platforms: :ruby
  gem 'execjs'
```
Export IP address of EC2 instance as local environment variable
```
  export PRODUCTION_SERVER_IP_ADDR=54.169.70.160
```
Deploy from local machine with Capistrano
```
  cap production deploy
```
Create production database if you see the following error ActiveRecord::NoDatabaseError: FATAL: database "merchant_app_production" does not exist
```
  # from ubuntu@ip-172-30-0-195:~$
  cd ~/apps/merchant/releases/${CURRENT_VERSION}
  RACK_ENV=production rake db:create
```

SSH into the EC2 instance to generate and copy new secret key

  # from ubuntu@ip-172-30-0-195:~$
  cd ~/apps/merchant/current
  bundle exec rake secret

Set the newly generated secret key as an environment variable using sudo vi ~/.profile
```
  export SECRET_KEY_BASE=${NEW_SECRET_KEY}
```

Check that you can access your application server

  curl 52.77.234.2 # replace with your IP address or domain
  # you should see HTML markup corresponding to your index/html

Run database seeding tasks (if any)

  # ubuntu@ip-172-30-0-195:~/apps/merchant/current$ 
  RACK_ENV=production bundle exec rake db:seed

Navigate to http://52.77.234.2 in a web browser window to view your application

Deploying to AWS EC2 using Capistrano

1. Create and login to a new EC2 instance

2. Setup EC2 instance with Ruby and RVM

3. Install and configure Nginx, Passenger and PostGreSQL

4. Setup Capistrano on local machine

5. Deploy the app with Capistrano