rails deployment in subdomain - ruby-on-rails

Question

on a dedicated server Debian 7, my default domain is www.example.org
I installed a mail server as smtp.example.org on localhost, running fine
I would like to deploy a rails app as a subdomain as : myapp.example.org
I deployed correctly the app, w Capistrano , and added a vhost :
<VirtualHost *:80>
ServerAdmin webmaster#example.org
ServerName myapp.example.org
ServerAlias myapp.example.org
DocumentRoot /var/www/rails/staging/myapp/current/public
<Directory /var/www/rails/staging/myapp/current/public>
AllowOverride All
Options -MultiViews
</Directory>
</VirtualHost>
the I enabled the site and restarted apache and tried to get http://myapp.example.org
but I always get the default site : http://www.example.org
my /etc/host is the following :
127.0.0.1 localhost smtp.example.org
localhost.localdomain localhost smtp
when I perform in the console : apache2ctl -S, I get
VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
...
*:80 is a NameVirtualHost
...
port 80 namevhost myapp.example.org (/etc/apache2/sites-enabled/myapp.example.org:1)
what did I missed ?

Answer 1

Found the answer at :
http://shapeshed.com/developing-subdomain-rails-sites-locally/
in the vhost file , I changed :
ServerAlias *.example.com
...
Options +FollowSymlinks +SymLinksIfOwnerMatch
RackEnv staging # or development or production