Mastering Nginx

Using the Mail Module

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Tying these three parts together, we have the complete authentication service:

#!/usr/bin/env rackup

# This is a basic HTTP server, conforming to the authentication

protocol

# required by NGINX's mail module.

#

require 'logger'

require 'rack'

module MailAuth

# setup a protocol-to-port mapping

Port = {

'smtp' => '25',

'pop3' => '110',

'imap' => '143'

}

class Handler

def initialize

# setup logging, as a mail service

@log = Logger.new("| logger -p mail.info")

# replacing the normal timestamp by the service name and pid

@log.datetime_format = "nginx_mail_proxy_auth pid: "

# the "Auth-Server" header must be an IP address

@mailhost = '127.0.0.1'

# set a maximum number of login attempts

@max_attempts = 3

# our authentication 'database' will just be a fixed hash for

# this example

# it should be replaced by a method to connect to LDAP or a

# database

@auths = { "test:1234" => '127.0.1.1' }

end

After the preceding setup and module initialization, we tell Rack which requests
we would like to have handled and define a get method to respond to requests

from NGINX.

def call(env)

# our headers are contained in the environment

@env = env