Web Servers

I have two favorite WebServers that I use currently. One which runs the blog and one that I run on my internal servers. Each of the below web servers each offer their own advantages to the mix which you can weigh and choose the one based on your requirements.

• Nginx (Pronounced "Engine X")
• LiteSpeed

For example LiteSpeed is not open source and there are two version one which is "more optimized" which costs quite a bit of money. Both the free and commercial versions are managed via a web interface. There is also an option at the time of installation to enable AWstats to monitor the traffic on your website. This is quite simple to setup and maintain. The upgrade process detailed blow is extremely simple to do and requires minimal time and effort.

Ruby on Rails Dispatcher

There are two methods of dispatching the Ruby on Rails web application that I use. One which is handled though an API which is installed via a gem (Ruby LSAPI) and one that runs a backend server which handles the dynamic Ruby content (Mongrel).

• LiteSpeed Ruby LSAPI
• Mongrel HA Cluster

If you have never setup a High-Available cluster before don't worry mongrel makes this process very simple. The configuration for a mongrel cluster is also extremely easy to create and understand. The config file itself can be as small as three lines. I would recommend against this as there are some options that would allow for a more secure mogrel cluster. As you can see below mine is a little bit longer but still you can agree with me that it is quite easy.

--- 
cwd: /path/to/railsapp/
log_file: log/mongrel.log
port: "8000"
environment: development
address: 127.0.0.1
pid_file: tmp/pids/mongrel.pid
servers: 3

Comparison

Both of the above options are very good choices when deploying Rails web applications. Each have drawbacks. For example if you are on a resticted VPS or other RAM limited server then the choice would be to use the Ruby-LSAPI because it requires only one ruby process to be run thus saving you tons of memory. On average a ruby process takes about 32MB of RAM. This can be quite detrimental if you only have 256MB on a VPS if you are running a 3 server HA mongrel cluster which would require (you guessed it) 96 MB of RAM! That is without the web proxy running which is required by mongrel cluster to proxy between the mongrel servers.

On to the comparison of the web servers that we use as a reverse proxy, Litespeed and Nginx. Both are wonderful web servers that are efficient and have a very small memory footprint. Each taking about only 2MB of RAM to run with minimal load. As the load increases the RAM usage does not increase that much. That being said Litespeed with Ruby-LSAPI is a wonderful choice when RAM is a consideration. When running development mongrel and Nginx might seem more responsive depending on the load and the amount of mongrel servers you have running in the cluster.

Packages Used

• Ruby 1.8.6 (Latest)
  • libiconv
  • readline
  • openssl
  • zlib
  • ncurses
• Nginx 0.5.29 (0.5.31 Latest Stable)
  • pcre
  • zlib
• PostgreSQL 8.2.4 (Latest)
• Ruby Gems 0.9.4 (Latest)
  • ruby
• Subversion 1.4.4 (Latest)
  • expat
  • neon
  • apr
  • apr-util
  • db44
  • gettext
  • libiconv
• Capisrtano 2.0.0 (Latest)
  • net-ssh (>= 1.0.10)
  • net-sftp (>= 1.1.0)
  • highline (> 0.0.0)
• Rails 1.2.3 (Latest)
  • rake (>= 0.7.2)
  • activesupport (= 1.4.2)
  • activerecord (= 1.15.3)
  • actionpack (= 1.13.3)
  • actionmailer (= 1.3.3)
  • actionwebservice (= 1.2.3)

Service Topology

HTTP Request
    |
    |
Nginx (Web Server)
    |
    |
Mongrel Cluster-----[SVN(Capistrano)]
| | |                                   
| | +mongrel=\ 
| +mongrel====[Rails App]
+mongrel======/

Installation

In this section I will go over the installation of the packages required for this rails deployment environment. I will try and discuss my reasons behind my choices. Please post any comments below. First and foremost we must install the package manager used in this tutorial. MacPorts is a delightful package manager for Mac OS X. It is psuedo-endorsed by Apple, Inc. (They host the web page) http://www.macports.org/

Nginx

At first I was quite skeptical about using this product, I did not believe the numbers I saw in performance so I decided to check it out. Really at the end of the day it doesnt matter what you use here as long as it is not LightTPD (because of incompatibilities between LightTPD and Mongrel) as long as the web server you use support some sort of proxy.

Installation

sudo port install nginx

IMPORTANT MacPorts will prompt you at the end of the installation and ask if you want to install a launchd service to start nginx on boot. I recommend this highly because it makes managing the server very easy.

Nginx Config File

worker_processes  1;

events {
    worker_connections  1024;
}

http {
  include       etc/nginx/mime.types;
  default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] $request '
  #                  '"$status" $body_bytes_sent "$http_referer" '
  #                  '"$http_user_agent" "$http_x_forwarded_for"';

  #access_log  logs/access.log  main;

  sendfile        on;
  #tcp_nopush     on;
    tcp_nodelay        on;

  #keepalive_timeout  0;
  keepalive_timeout  65;

  gzip  on;

  upstream mongrel {
    server 127.0.0.1:8000;
    server 127.0.0.1:8001;
    server 127.0.0.1:8002;
  }

  server {
    listen       80;
    server_name  localhost;

    root /Users/rvalente/Sites/snoompa/public;
    index  index.html index.htm;

    location / {
      proxy_set_header  X-Real-IP  $remote_addr;
      proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_redirect false;
      if (-f $request_filename/index.html) {
        rewrite (.*) $1/index.html break;
      }
      if (-f $request_filename.html) {
        rewrite (.*) $1.html break;
      }
      if (!-f $request_filename) {
        proxy_pass http://mongrel;
        break;
      }
    }
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   html;
    }
  }
}

Ruby

Ruby is self explanatory, if you are questioning why I am installing this you should prolly be reading http://www.ruby-lang.org. I have always used the latest version of Ruby and have always had the best luck with that stradegy. That being said it is quick and easy when using a package manager.

Installation

sudo port install ruby

Verification

To make sure you are running the correct version of Ruby run the following command:

ruby -v
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.10.1]

Ruby Gems

Ruby gems is the package manager used to install all the software used within ruby. For example if you wanted to find a gem that dealt with snmp communication you could run the following command: gem search --remote snmp Once the rubygem package manager is installed you can use with MacPorts to update it or you could use itself by running the command port update rubygems

Installation

sudo port install rb-rubygems

Hint: Open a terminal window and run gem_server and then navigate in your web browser to http://localhost:8808 This is the rdoc for each of the packages installed via the gem package manager.

Ruby on Rails

Here is the money application right here. Ruby on Rails is the magic that pulls all this together. Just with a quick one-line command you will have all the power you need to create web applications.

Installation

sudo gem install -y rails

Note: You may need to run the previous command twice. There is some sort of bug which makes the rails install fail the first time you run this command.

PostgreSQL 8.2.4

PostgreSQL is a superior database built for speed and scalability. This database in my humble opinion beats just about everything that MySQL might have to offer. PostgreSQL 8 has a plethora of benefits over mysql including offering a better user experience. PostgreSQL has been made extremely easy to install on the mac. It has been packaged and maintained by Andy Satori. The sourceforge link to download this package installer is below.

http://sourceforge.net/project/showfiles.php?group_id=133151&package_id=146535\

After the PostgreSQL database server is installed you will need the API to connect Ruby to the database server. This is accomplished with the following command:

sudo gem install postgres -- --with-pgsql-dir=/Library/PostgreSQL8/

Mongrel

Mongrel is a wonderful and fast web server for hosting rails web applications. The mongrel_cluster suite of applications makes creating High Availability web applications very easy. The configuration file has an easy syntax to follow and write yourself.

Installation

sudo gem install -y mongrel_cluster

Configuration

The configuration for mongrel is actually quite easy, below is an example of the mongrel_rails command to configure the cluster portion on mongrel. Since rails does not support thread synchronization it is highly recommended to run multiple mongrel clusters even on a development box. I currently run three as you saw by the upstream directive in the nginx configuration.

mongrel_rails cluster::configure -h
Usage: mongrel_rails <command> [options]
    -e, --environment ENV            Rails environment to run as
    -p, --port PORT                  Starting port to bind to
    -a, --address ADDR               Address to bind to
    -l, --log FILE                   Where to write log messages
    -P, --pid FILE                   Where to write the PID
    -c, --chdir PATH                 Change to dir before starting (will be expanded)
    -t, --timeout SECONDS            Timeout all requests after SECONDS time
    -m, --mime PATH                  A YAML file that lists additional MIME types
    -r, --root PATH                  Set the document root (default 'public')
    -n, --num-procs INT              Number of processor threads to use
    -B, --debug                      Enable debugging mode
    -S, --script PATH                Load the given file as an extra config script.
    -N, --num-servers INT            Number of Mongrel servers
    -C, --config PATH                Path to cluster configuration file
        --user USER
                                     User to run as
        --group GROUP
                                     Group to run as
        --prefix PREFIX
                                     Rails prefix to use
    -h, --help                       Show this message
        --version                    Show version

Now that we see all the options possible in the mongrel_rails configuration of the cluster here is an example of a simple configuration file.

--- 
log_file: log/mongrel.log
port: 8000
pid_file: tmp/pids/mongrel.pid
servers: 3
debug: false
docroot: public
address: 127.0.0.1
cwd: /path/to/rails/app

Subversion

Subversion is a superb version control system that is used abundantly in the rails world. Capistrano leverages this when deploying applications over ssh to a server. Subversion is the version control system we use here at SysAdmins' Chronicles for our development.

Installation

sudo port install subversion

Configuration

Subversion is quite easy to configure. Depending on the use of the subversion server changes a few aspects. If the server will be run locally then there is no need for a server and can be accessed via the file:/// prepend. One thing to note about that is the lack of support from capistrano using that method. Subversion repositories can be served up through many other ways included the shipped svnserve application as well as svn+ssh:// which is automatically accessible if a subversion server is running and uses user accounts as authentication, lastly you can use http/https via the DAV protocol to host the repository. For this purpose I will use the svn+ssh:// method because there is no configuration other than the initial creation of the repository.

svnadmin create --fs-type=fsfs ~/repo

Note: I recommend using the --fs-type=fsfs flag because it is superior to the berkeley db implementation originally used in the older versions of subversion and now using the fsfs file structure for the repository is recommended.

Capistrano

Capistrano is an amazing solution for application deployment not only for web applications and ruby on rails but also scripts and system administration tasks with any server. More on that topic later. For now just enjoy the simplistic capistrano deployment workflow for Ruby on Rails.

Installation

sudo gem install -y capistrano