I must admit I've been working a long time with Amazon Web Services and have ignored a little the world of VPS, but obviously not all of our customers are willing to pay such high rates (after the year), plus not all applications require a distributed and scalable architecture. Therefore, DigitalOcean gives us a perfect hybrid platform between a classic VPS and a cloud computing service payed by consumption.
When I started working with these virtual servers called Droplets I had little hope that the economic ones might effectively support the workload, but to my surprise those exceeded my expectations and I have become an immediate fan of this company.
Now we get into the technical side that surely you are interested in. The technology that I most enjoy working is Ruby, coupled with the framework Ruby on Rails, why is my favorite?, it is a long topic that surely I could dwell on one or more articles, so let’s go to what we want; make a deployment (deploy) of our application faster in the most economical Droplet of DigitalOcean.
DigitalOcean has a service called 1-click application. This service let us create a Droplet with an atmosphere made specific to the technology that we need to work, in our case it is a Droplet with Ruby on Rails 4+, Nginx, and PostgreSQL, this latter recently added and that eliminates the classic MySQL of the recipe, in my opinion; the best they could do. PostgreSQL vs. MySQL is another issue that surely arouse much controversy.
Create the Droplet is easy, by just putting the name, size (in our case $5), region and select the type of application (Ruby on Rails) we will obtain in less than a minute our Rails server.
When you finish creating, it gives us an IP address with a Ruby on Rails application working perfectly, easiest impossible.
Now it's time to check our email where DigitalOcean sent us the data to make a SSH to our server, something like this:
Your new droplet has been created! You can access it using the following credentials: IP Address: 126.96.36.199 Username: root Password: hlbjnspvzodd
We enter to our SSH session and the first thing it will ask us is to change the password, then it will give us a welcome message together with the connection data we need to install our application. The first thing we will see is the FTP.
You can use the following SFTP credentials to upload your webpages (using FileZilla/WinSCP/Rsync): Host: 188.8.131.52 User: rails Pass: hlbjnspasdasdvzodd
Next, we find the credentials of the database installed:
You can use the following Postgress database credentials: * User: rails * Pass: KHSYSRSOYcGT
By connecting via FTP will lead us to the project path (/home/rails/rails_project). There we will supplant all files for our application, it is worth noting that we do this assuming that you know Git and that you are keeping the code in some repository (GitHub, BitBucket, etc), we neither wanted to include the deployment with capristrano that we consider the best way to make deployments based on our Git repository. This will be deepen in a future article.
Now to replace the files of our project we have to keep in mind that we need to change certain details of our configuration that DigitalOcean places as environment variable, these data can be seen in /etc/default/unicorn
What we must change in our application:
rails/config/secrets.yml production: secret_key_base: <%= ENV['SECRET_KEY_BASE'] %> rails/config/database.yml production: <<: *default database: app_production username: rails password: <%= ENV['APP_DATABASE_PASSWORD'] %>
Before we start, we need to update the server libraries
Then something important, for applications that use image management, for example CarrierWave (Ruby Gem) we must install ImageMagick.
sudo apt-get install imagemagick libmagickwand-dev
Now the next step is optional and is about using the Linux swap, I do that because many times I use Gems that when installed, consume a lot of memory, and nothing worse than seeing the hateful message of lack of memory, obviously, this we wouldn’t have to do it if we had a more powerful server.
first step: sudo dd if=/dev/zero of=/swapfile bs=1024 count=256k Second step: sudo mkswap /swapfile the result must be something like this: Setting up swapspace version 1, size = 262140 KiB no label, UUID=103c4545-5fc5-47f3-a8b3-dfbdb64fd7eb to Activate sudo swapon /swapfile now set each time you restart your server must soloists do this: Abrir este archivo sudo nano /etc/fstab and add this line /swapfile none swap sw 0 0
Since we have done with the operating system, it's time to our application server, remember that the server is running, so it is a good idea to turn it off for the moment.
service unicorn stop
Before running the Bundle we must add the environment variable data base (APP_DATABASE_PASSWORD) to create structure and do migrate at any time, this is in /etc/default/unicorn at the end of the file, just copy and add it as session variable. We will do it with the user we are connected (root) that was sent to us by DigitalOcean, in order to make it faster but for safety reasons you should use a different user.
Copy the environment variable database file as follows : vi /etc/default/unicorn And run export APP_DATABASE_PASSWORD=PASSWORD-FROM-FILE And then we paste in the end of the file .profile for the last time we are connected vi ~/.profile
Then we start to upgrade and install the Gems of our project
cd /home/rails/rails_project bundle update
(Review) Now you should change PostgreSQL configuration file, the reason? well, we don't want to see this awful error "Peer authentication failed for user"
Modified the following file: /etc/postgresql/9.3/main/pg_hba.conf
local all all peer
You must change "peer" with "trust"
Now you just have to reboot the server, you can do from the console with this command (sudo shutdown -r now) or you can do it directly from in your digitalocean session, within your Droplet go to the Power option and then you click on the option "Power Cycle"
We create the database and project structures
rake db:create RAILS_ENV="production" rake db:migrate RAILS_ENV="production" rake db:seed RAILS_ENV="production"
Precompile all assets
RAILS_ENV=production rake assets:precompile
If we have no problems, we must be prepared to start the Unicorn server applications, before this if we work with Devise remember that the file rails/config/initializers/devise.rb has a config.secret_key that we must configure with our environment variables.
service unicorn start
Now by going to our IP we must see our deployed application.
The log file of Unicorn can be see it by the following route
I hope this little guide has helped, if you have any questions or suggestions feel free to email me.