環境：

ubuntu 14.04
mina 0.3
rails 4.1.4
(其他參考上一篇文章設定環境)

以後操作流程：

安裝mina gem
指定專案使用的ruby版本
mina init (初始化)
修改deploy.rb文件
mina setup (創建環境)
mina deploy (部署)
設定nginx vhost (參考上一篇文章）
重啟nginx server

實際操作：

1. 安裝gem

gem 'mina'

2. 初始化

$ mina init

3. 指定專案使用的ruby版本

$ rbenv local 2.1.2
$ rbenv rehash
$ git add .
$ git commit -m “xxxx”

4. 修改deploy.rb

require 'mina/bundler'
require 'mina/rails'
require 'mina/git'
require 'mina/rbenv'  # for rbenv support. (http://rbenv.org)

set :domain, 'rails4.coolsea.net'
set :deploy_to, '/home/apps/my_project/rails4'
set :repository, 'git@github.com:coolsea/coolsea-store.git'
set :branch, 'master'

# Manually create these paths in shared/ (eg: shared/config/database.yml) in your server.
# They will be linked in the 'deploy:link_shared_paths' step.
set :shared_paths, ['config/database.yml', 'log']

# Optional settings:
   set :user, 'apps'    # Username in the server to SSH to.

task :environment do
  # If you're using rbenv, use this to load the rbenv environment.
  # Be sure to commit your .rbenv-version to your repository.
    invoke :'rbenv:load'

  # For those using RVM, use this to load an RVM version@gemset.
  # invoke :'rvm:use[ruby-1.9.3-p125@default]'
end

##########################################################################
#
# Create new host tasks
# Tasks below are related to deploying a new version of the application
#
##########################################################################
 
# Function extracted from http://blog.nicolai86.eu/posts/2013-05-06/syncing-database-content-down-with-mina
# allowing to read the content of the database.yml file
RYAML = <<-BASH
function ryaml {
  ruby -ryaml -e 'puts ARGV[1..-1].inject(YAML.load(File.read(ARGV[0]))) {|acc, key| acc[key] }' "$@"
};
BASH
 



# Put any custom mkdir's in here for when `mina setup` is ran.
# For Rails apps, we'll make some of the shared paths that are shared between
# all releases.
task :setup => :environment do
  queue! %[mkdir -p "#{deploy_to}/shared/log"]
  queue! %[chmod g+rx,u+rwx "#{deploy_to}/shared/log"]

  queue! %[mkdir -p "#{deploy_to}/shared/config"]
  queue! %[chmod g+rx,u+rwx "#{deploy_to}/shared/config"]

  queue! %[touch "#{deploy_to}/shared/config/database.yml"]
  queue  %[echo "-----> Be sure to edit 'shared/config/database.yml'."]
  invoke :'setup:db:database_yml'
end



# Populate file database.yml with the appropriate rails_env
# Database name and user name are based on convention
# Password is defined by the user during setup
desc "Populate database.yml"
task :'setup:db:database_yml' => :environment do
  puts "Enter a name for the new database"
  db_name = STDIN.gets.chomp
  puts "Enter a user for the new database"
  db_username = STDIN.gets.chomp
  puts "Enter a password for the new database"
  db_pass = STDIN.gets.chomp
  # Virtual Host configuration file
  database_yml = <<-DATABASE.dedent
    #{rails_env}:
      adapter: mysql2
      encoding: utf8
      database: #{db_name}
      username: #{db_username}
      password: #{db_pass}
      host: localhost
      timeout: 5000
  DATABASE
  queue! %{
    echo "-----> Populating database.yml"
    echo "#{database_yml}" > #{deploy_to!}/shared/config/database.yml
    echo "-----> Done"
  }
  invoke :'setup:db'

end
 
# Create the new database based on information from database.yml
# In this application DB, user is given full access to the new DB
desc "Create new database"
task :'setup:db' => :environment do
  queue! %{
    echo "-----> Import RYAML function"
    #{RYAML}
    echo "-----> Read database.yml"
    USERNAME=$(ryaml #{deploy_to!}/#{shared_path!}/config/database.yml #{rails_env} username)
    PASSWORD=$(ryaml #{deploy_to!}/#{shared_path!}/config/database.yml #{rails_env} password)
    DATABASE=$(ryaml #{deploy_to!}/#{shared_path!}/config/database.yml #{rails_env} database)
    echo "-----> Create SQL query"
    Q1="CREATE DATABASE IF NOT EXISTS $DATABASE;"
    Q2="GRANT USAGE ON *.* TO $USERNAME@localhost IDENTIFIED BY '$PASSWORD';"
    Q3="GRANT ALL PRIVILEGES ON $DATABASE.* TO $USERNAME@localhost;"
    Q4="FLUSH PRIVILEGES;"
    SQL="${Q1}${Q2}${Q3}${Q4}"
    echo "-----> Execute SQL query to create DB and user"
    echo "-----> Enter MySQL root password on prompt below"
    #{echo_cmd %[mysql -uroot -p -e "$SQL"]}
    echo "-----> Done"
  }
end

desc "Deploys the current version to the server."
task :deploy => :environment do
  deploy do
    # Put things that will set up an empty directory into a fully set-up
    # instance of your project.
    invoke :'git:clone'
    invoke :'deploy:link_shared_paths'
    invoke :'bundle:install'
    invoke :'rails:db_migrate'
    invoke :'rails:assets_precompile'
  end
end


task :restart do
  queue 'sudo service nginx restart'
end
 
#########################################################################
#
# Libraries
#
##########################################################################
 
#
# See https://github.com/cespare/ruby-dedent/blob/master/lib/dedent.rb
#
class String
  def dedent
    lines = split "\n"
    return self if lines.empty?
    indents = lines.map do |line|
      line =~ /\S/ ? (line.start_with?(" ") ? line.match(/^ +/).offset(0)[1] : 0) : nil
    end
    min_indent = indents.compact.min
    return self if min_indent.zero?
    lines.map { |line| line =~ /\S/ ? line.gsub(/^ {#{min_indent}}/, "") : line }.join "\n"
  end
end

修改
set :domain
set :deploy_to
set :repository
set :shared_paths, [‘config/database.yml’, ‘log’, ‘config/config.yml’, ‘config/secrets.yml’]
#註：把不能git的檔案，手動先增到伺服器的shared資料夾裡，然後把路徑添加在這裡。

5. 創建環境

$ mina setup

6. 部署

$ mina deploy
$ mina restart (重啟nginx server)

參考網址：

Q & A：

Missing secret_key_base for ‘production’ environment, set this value in config/secrets.yml

[Rails4]使用Mina部署到ubuntu server

環境：