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Deploy NodeJS project with Capistrano

Because it's possible, in 18 August 2014

Install Capistrano

You need to have ruby and gem installed in order to install capistrano.

$ gem install capistrano
$ gem install capistrano-ext

Server

We need to configure the destination server in order to deploy our application.

Create a deploy user

The first step is to create this user :

$ adduser deploy

Then we need to change the user's password to an untypable string, guaranteeing that the user has no password which can be used to log in.

$ passwd -l deploy

SSH key

In order to deploy with the deploy user we need to have an ssh key in its authorized keys.

On your local machine :

$ ssh-keygen -t rsa -C "test@example.com"

You'll be prompted for a passphrase. Enter one and remember it.

In order to not be prompted every time the passphrase you just entered we can use the ssh agent. We can see which keys are loaded in the SSH agent by running :

$ ssh-add -l

If you don't see any keys listed, you can simply run ssh-add:

$ ssh-add
Identity added: /home/me/.ssh/id_rsa (/home/me/.ssh/id_rsa)

Now that the key is loaded into the agent you can print it by doing so :

$ ssh-add -L
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCiULq......qnBZr test@example.com

Now we need to put this key into the deploy user /home/deploy/.ssh/authorized_keys file on the server.

me@localhost $ ssh root@remote
root@remote $ su - deploy
deploy@remote $ cd ~
deploy@remote $ mkdir .ssh
deploy@remote $ echo "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCiULq........qnBZr test@example.com" >> .ssh/authorized_keys
deploy@remote $ chmod 700 .ssh
deploy@remote $ chmod 600 .ssh/authorized_keys

If everything went good, we should now be able to do something like this:

me@localhost $ ssh deploy@one-of-my-servers.com 'hostname; uptime'
one-of-my-servers.com
19:23:32 up 62 days, 44 min, 1 user, load average: 0.00, 0.01, 0.05

More info on this section on capistrano website

Nodejs and npm

If it's not already the case, we have to install nodejs and npm on our server. Git has to be install too in order for Capistrano to clone the repo.

sudo apt-get update
sudo apt-get install nodejs npm
sudo apt-get install git

If your server is running on ubuntu you might need to create a symlink for node like so sudo ln -s /usr/bin/nodejs /usr/bin/node. More info on Stack Overflow

Forever

We are going to use forever for nodejs which make sure a nodejs process will always stays up.

npm install forever -g

Init capistrano for the project

Go to your project and init capistrano :

cd /path/to/your/project
cap install

This will create the following files :

├── Capfile
├── config
│   ├── deploy
│   │   ├── production.rb
│   │   └── staging.rb
│   └── deploy.rb
└── lib
    └── capistrano
            └── tasks

You need to have you project under git with a remote repository in order for Capistrano to clone it on the destination server.

Now that we have the different files generated we are going to edit our configuration.

In config/deploy.rb edit the following line to your need :

set :application, 'test_app'
set :repo_url, 'git@github.com:username/test_app.git'
set :deploy_to, '/var/www/test_app'

The above lines indicate :

Make sure that :

If it not the case let's create it and give permissions to deploy. Run the following command on your server :

mkdir -p /var/www/test_app
chown -R deploy:deploy /var/www/test_app

Then replace into config/deploy.rb the namespace :deploy do section with the following one :

namespace :deploy do

  desc "Stop Forever"
  task :started do
    on roles(:app) do
      execute "forever stopall", raise_on_non_zero_exit: false
    end
  end

  desc "Install node modules non-globally"
  task :npm_install do
    on roles(:app) do
      execute "cd #{current_path} && npm install"
    end
  end

  desc 'Restart application'
  task :restart do
    on roles(:app), in: :sequence, wait: 5 do
     execute  :default_env['NODE_ENV'], " forever start #{current_path}/app.js", raise_on_non_zero_exit: true
    end
  end

  after :publishing, :restart
  before :restart, :npm_install

end

The section above will describe 3 tasks for the deploy namespace:

You can see that we defined a very basic rule at the end of the section. It basically says:

Once you are done publishing then restart the project, but before you can restart the project, you have to install the dependencies.

Production configuration

We are almost done, we need to configure the config/deploy/production.rb where we are going to write the specificity for the production environment.

Replace the content of your file with the following :

role :app, %w{deploy@0.0.0.0}

server '0.0.0.0', user: 'deploy', roles: %w{app}

set :default_env, {
  'NODE_ENV' => 'production'
}

set :ssh_options, {
    forward_agent: true,
}

In this file we :

Deploy

Now we should be ready to deploy.

Run the following command :

$ cap production deploy
INFO[b54f6d4a] Running /usr/bin/env mkdir -p /tmp/test_app/ on 0.0.0.0
DEBUG[b54f6d4a] Command: ( NODE_ENV=production /usr/bin/env mkdir -p /tmp/test_app/ )
INFO[b54f6d4a] Finished in 0.972 seconds with exit status 0 (successful).
DEBUG Uploading /tmp/test_app/git-ssh.sh 0.0%
INFO Uploading /tmp/test_app/git-ssh.sh 100.0%
.....
DEBUG[8f30fec2] Command: echo "Branch master (at 11d2638) deployed as release 20140818152948 by wendannor" >> /var/www/test_app/revisions.log
INFO[8f30fec2] Finished in 0.037 seconds with exit status 0 (successful).

Hope this post helped you deploy your nodejs application with Capistrano.

Sources :

http://capistranorb.com/

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