开始被设计成 Apache 的 module，用来部署 Ruby on Rails，叫mod_rails
后来不断发展成独立的 Ruby Web Server，改名Passenger

下面是关于 Passenger 的一些历史。

Sinatra 是一个基于 Ruby 的 DSL，方便开发者快速创建 Web 应用。官方文档里有更详细的说明。

Hello Sinatra

安装 rvm

$ gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3

$ curl -sSL https://get.rvm.io | bash -s stable

$ rvm -v
rvm 1.28.0 (latest) by Wayne E. Seguin <[email protected]>, Michal Papis <[email protected]> [https://rvm.io/]

安装 Ruby

$ rvm install 2.3.3

$ ruby -v
ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-linux]

安装 Sinatra

$ gem install sinatra

码一段代码

$ vi hello_sinatra.rb

require 'sinatra'

get '/' do
  'Hello, Sinatra'
end

测试

$ ruby hello_sinatra.rb
[2017-02-13 01:32:47] INFO  WEBrick 1.3.1
[2017-02-13 01:32:47] INFO  ruby 2.3.3 (2016-11-21) [x86_64-linux]
== Sinatra (v1.4.8) has taken the stage on 4567 for development with backup from WEBrick
[2017-02-13 01:32:47] INFO  WEBrick::HTTPServer#start: pid=7962 port=4567

访问 http://localhost:4567，能看到输出Hello, Sinatra。

配置 Apache 和 Passenger

安装 Apache

$ sudo apt-get install apache2

安装 Passenger

按照官网上提供的安装向导，生成具体的安装步骤。

relevant integration mode
- Apache
- Passenger open source
operating system / installation method
- Debian, Ubuntu (With APT)
- Ubuntu 16.04 LTS (Xenial)

# Step 1: install Passenger packages

## Install our PGP key and add HTTPS support for APT
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 561F9B9CAC40B2F7
$ sudo apt-get install -y apt-transport-https ca-certificates

## Add our APT repository
$ sudo sh -c 'echo deb https://oss-binaries.phusionpassenger.com/apt/passenger xenial main > /etc/apt/sources.list.d/passenger.list'
$ sudo apt-get update

## Install Passenger + Apache module
$ sudo apt-get install -y libapache2-mod-passenger

# Step 2: enable the Passenger Apache module and restart Apache

$ sudo a2enmod passenger
$ sudo apache2ctl restart

# Step 3: check installation

$ sudo /usr/bin/passenger-config validate-install
 * Checking whether this Phusion Passenger install is in PATH... ✓
 * Checking whether there are no other Phusion Passenger installations... ✓

$ sudo /usr/sbin/passenger-memory-stats
Version: 5.0.8
Date   : 2015-05-28 08:46:20 +0200

---------- Apache processes ----------
PID    PPID   VMSize    Private  Name
--------------------------------------
3918   1      190.1 MB  0.1 MB   /usr/sbin/apache2
...

----- Passenger processes ------
PID    VMSize    Private   Name
--------------------------------
12517  83.2 MB   0.6 MB    Passenger watchdog
12520  266.0 MB  3.4 MB    Passenger core
12531  149.5 MB  1.4 MB    Passenger ust-router
...

# Step 4: update regularly

$ sudo apt-get update
$ sudo apt-get upgrade

Sinatra 部署文件夹

在/var/www下，新建hello-sinatra文件夹，结构如下。

hello-sinatra/
├── config.ru
├── hello.rb
├── logs/
├── pids/
├── public/
└── tmp/
    └── restart.txt

文件hello.rb的内容为

require 'sinatra/base'

class HelloSinatra < Sinatra::Base
  get '/' do
    'Hello, Sinatra'
  end
end

文件config.ru的内容为

require File.expand_path('../hello.rb', __FILE__)
use Rack::ShowExceptions  # 访问未定义的路由时，在网页上显示异常信息
run HelloSinatra.new

配置 Apache 的 vhost

从/etc/apache2/sites-available里拷贝一份默认的 vhost 模板。

$ sudo cp 000-default.conf hello-sinatra.conf

在/etc/apache2/sites-enabled下，新建一个符号链接到hello-sinatra.conf。

$ sudo ln -s ../sites-available/hello-sinatra.conf .
$ sudo vi hello-sinatra.conf

<VirtualHost *:80>
    DocumentRoot /var/www/hello-sinatra/public  # !!

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    PassengerRuby /home/aaron67/.rvm/gems/ruby-2.3.3/wrappers/ruby  # !!

    <Directory /var/www/hello-sinatra/public>  # !!
        Allow from all
        Options -MultiViews
    </Directory>
</VirtualHost>

两点注意：

DocumentRoot和Directory里的路径要写到public文件夹
PassengerRuby的值，通过下面的命令查看

$ passenger-config about ruby-command
passenger-config was invoked through the following Ruby interpreter:
  Command: /home/aaron67/.rvm/gems/ruby-2.3.3/wrappers/ruby
  Version: ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-linux]
  To use in Apache: PassengerRuby /home/aaron67/.rvm/gems/ruby-2.3.3/wrappers/ruby  # <== 看这里
  To use in Nginx : passenger_ruby /home/aaron67/.rvm/gems/ruby-2.3.3/wrappers/ruby
  To use with Standalone: /home/aaron67/.rvm/gems/ruby-2.3.3/wrappers/ruby /usr/bin/passenger start

重启 Apache 服务。

$ sudo service apache2 restart

测试

浏览器访问服务器地址，显示的是 Apache 默认的欢迎页面（文件位置在/var/www/html/index.html）。

这是由于000-default.conf和hello-sinatra.conf配置了不同的DocumentRoot，但没配置不同的ServerName。

vhost配置文件	ServerName	DocumentRoot
000-default.conf	无	/var/www/html
hello-sinatra.conf	无	/var/www/hello-sinatra

更多关于 Apache Name-based Virtual Hosts 的内容，可以阅读官方文档。

测试用的虚拟机没有域名绑定，所以简单的直接禁用掉默认 site 就好。

$ sudo a2dissite 000-default
Site 000-default disabled.
To activate the new configuration, you need to run:
  service apache2 reload

重新加载或重启 Apache 服务使配置生效。

一个错误

查看 Apache 的日志文件/var/log/apache2/error.log，刚才的访问会输出如下错误。

App 9888 stdout:
App 9888 stderr:  [passenger_native_support.so] trying to compile for the current user (nobody) and Ruby interpreter...
App 9888 stderr:      (set PASSENGER_COMPILE_NATIVE_SUPPORT_BINARY=0 to disable)
App 9888 stderr:      Warning: compilation did not succeed. To learn why, read this file:
App 9888 stderr:      /tmp/passenger_native_support-1ozcjtk.log
App 9888 stderr:  [passenger_native_support.so] finding downloads for the current Ruby interpreter...
App 9888 stderr:      (set PASSENGER_DOWNLOAD_NATIVE_SUPPORT_BINARY=0 to disable)
App 9888 stderr:      # tar xzf rubyext-ruby-2.3.3-x86_64-linux.tar.gz
App 9888 stderr:      # rm -f rubyext-ruby-2.3.3-x86_64-linux.tar.gz
App 9888 stderr:      Checking whether downloaded binary is usable...
App 9888 stderr:      # /home/aaron67/.rvm/gems/ruby-2.3.3/wrappers/ruby -I. test.rb
App 9888 stderr:      Binary is usable.
App 9888 stderr:      # current user is: nobody
App 9888 stderr:      # mkdir -p /nonexistent/.passenger/native_support/5.1.2/ruby-2.3.3-x86_64-linux
App 9888 stderr:      Encountered permission error, but no more directories to try. Giving up.
App 9888 stderr:      -------------------------------
App 9888 stderr:  [passenger_native_support.so] will not be used (cannot compile or download)
App 9888 stderr:   --> Passenger will still operate normally.
App 9924 stdout:

看起来像是目录权限问题，修改/var/www/hello-sinatra文件夹的 owner 成当前用户。

$ sudo chown -R aaron67:aaron67 /var/www/hello-sinatra/

重启服务，搞定。

花拳绣腿 & 柴米油盐

在 Ubuntu Server 16.04 上配置 Apache 和 Passenger 部署 Sinatra 应用