Deploying mailman with daemon and capistrano

Recently, I wanted to store the contents of the email I receive on my email to database of my rails application. I was able to achieve my goal with mailman gem. I learned about it from railscasts. In this post, I will write about how I implemented it.

I added following to my Gemfile

gem mailman

After that, I ran bundle install from my terminal.

Then, I added the following code to my script/mailman_server.rb:

#!/usr/bin/env ruby require "rubygems"
require "mailman"
require File.expand_path(File.join(File.dirname(__FILE__), '..', 'config', 'environment'))

Mailman.config.rails_root = '.'
Mailman.config.logger = Logger.new("log/mailman.log")
Mailman.config.pop3 = {

server: 'mail.your-server.de', port: 110,
username: 'your_username',
password: 'your_password'

}
Mailman::Application.run do

default do

begin
    MyModel.receive_mail(message)
rescue Exception => e
    Mailman.logger.error "Exception occurred while receiving message:\n#{message}"
    Mailman.logger.error [e, *e.backtrace].join("\n")
end

end

end

I wanted to save the body of the mail to body attribute of my MyModel database. So, the model MyModel consists of receive_mail now looks like following:

def self.receive_mail(message)

message_text = message.multipart? ? (message.text_part ? message.text_part.body.decoded : nil) : message.body.decoded
my_model_params = { body: message_text}
MyModel.create!(my_model_params)

end

With the program written above, I stored the contents of the email that I received at username as mentioned in mailman_server.rb in my my_model table of the database.

Now, I wanted to run the mailman_script.rb script with daemons gem, so that I could run the script with just start, stop and restart commands.

In my Gemfile, I added the following line gem daemons and run bundle install.

I added a new file in the script folder called mailman_daemon.rb, that contains following code:

#!/usr/bin/env ruby

require "rubygems"
require "bundler/setup"
require "daemons"

Daemons.run('script/mailman_server.rb')

Now the hardest part that I had was setting up the capistrano with daemon. The main task is to start, stop and restart daemon with capistrano. So, that we don't have to start our daemon server with each deployment. I added the following to config/deploy.rb:

# Mailman configuration
namespace :mailman do

desc "Mailman::Start"
task :start, :roles => [:app] do

run "cd #{current_path};RAILS_ENV=#{rails_env} script/mailman_daemon.rb start"

end
desc "Mailman::Stop" task :stop, :roles => [:app] do

run "cd #{current_path};RAILS_ENV=#{rails_env} script/mailman_daemon.rb stop"

end
desc "Mailman::Restart" task :restart, :roles => [:app] do

mailman.stop mailman.start

end

end
before "deploy:cleanup", "mailman:restart"

Now, the rails application is ready to be deployed with capistrano, mailman and daemon. Have fun!