4.4.3. Cheating with Apache->httpd_conf

NameVirtualHost         10.0.0.10

<VirtualHost 10.0.0.10>
    ServerName  tech.intranet
    DocumentRoot /home/httpd/httpd_perl/docs/tech
    ServerAdmin webmaster@tech.intranet
</VirtualHost>

<VirtualHost 10.0.0.10>
    ServerName   suit.intranet
    DocumentRoot /home/httpd/httpd_perl/docs/suit
    ServerAdmin webmaster@suit.intranet
</VirtualHost>

You can write it in Perl:

use Socket;
use Sys::Hostname;
my $hostname = hostname( );
(my $domain = $hostname) =~ s/[^.]+\.//;
my $ip = inet_ntoa(scalar gethostbyname($hostname || 'localhost'));
my $doc_root = '/home/httpd/docs';

Apache->httpd_conf(qq{
NameVirtualHost $ip

<VirtualHost $ip>
  ServerName  tech.$domain
  DocumentRoot $doc_root/tech
  ServerAdmin webmaster\@tech.$domain
</VirtualHost>

<VirtualHost $ip>
  ServerName   suit.$domain
  DocumentRoot $doc_root/suit
  ServerAdmin  webmaster\@suit.$domain
</VirtualHost>
 });

First, we prepare the data, such as deriving the domain name and IP address from the hostname. Next, we construct the configuration file in the "usual" way, but using the variables that were created on the fly. We can reuse this configuration file on many machines, and it will work anywhere without any need for adjustment.

Now consider that you have many more virtual hosts with a similar configuration. You have probably already guessed what we are going to do next:

use Socket;
use Sys::Hostname;
my $hostname = hostname( );
(my $domain = $hostname) =~ s/[^.]+\.//;
my $ip = inet_ntoa(scalar gethostbyname($hostname || 'localhost'));
my $doc_root = '/home/httpd/docs';
my @vhosts = qw(suit tech president);

Apache->httpd_conf("NameVirtualHost $ip");

for my $vh (@vhosts) {
  Apache->httpd_conf(qq{
<VirtualHost $ip>
  ServerName  $vh.$domain
  DocumentRoot $doc_root/$vh
  ServerAdmin webmaster\@$vh.$domain
</VirtualHost>
 });
}

In the loop, we create new virtual hosts. If we need to create 100 hosts, it doesn't take a long time—just adjust the @vhosts array.