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NAME

Getting Your Feet Wet with mod_perl

Description

This chapter gives you the bare minimum information to get you started with mod_perl 2.0. For most people it's sufficient to get going.

Installation

If you are a Win32 user, please refer to the Win32 installation document.

First, download the mod_perl 2.0 source.

Before installing mod_perl, you need check that you have the mod_perl 2.0 prerequisites installed. Apache and the right Perl version have to be built and installed before you can proceed with building mod_perl.

In this chapter we assume that httpd and all helper files were installed under $HOME/httpd/prefork, if your distribution doesn't install all the files under the same tree, please refer to the complete installation instructions.

Now, configure mod_perl:

  % tar -xvzf mod_perl-2.x.xx.tar.gz
  % cd modperl-2.0
  % perl Makefile.PL MP_APXS=$HOME/httpd/prefork/bin/apxs MP_INST_APACHE2=1

where MP_APXS is the full path to the apxs executable, normally found in the same directory as the httpd executable, but could be put in a different path as well.

Finally, build, test and install mod_perl:

  % make && make test && make install

Become root before doing make install if installing system-wide.

If something goes wrong or you need to enable optional features please refer to the complete installation instructions.

Configuration

If you are a Win32 user, please refer to the Win32 configuration document.

Enable mod_perl built as DSO, by adding to httpd.conf:

  LoadModule perl_module modules/mod_perl.so

Next, tell Perl where to find mod_perl2 libraries:

  PerlModule Apache2

There are many other configuration options which you can find in the configuration manual.

If you want to run mod_perl 1.0 code on mod_perl 2.0 server enable the compatibility layer:

  PerlModule Apache::compat

For more information see: Migrating from mod_perl 1.0 to mod_perl 2.0.

Server Launch and Shutdown

Apache is normally launched with apachectl:

  % $HOME/httpd/prefork/bin/apachectl start

and shut down with:

  % $HOME/httpd/prefork/bin/apachectl stop

Check $HOME/httpd/prefork/logs/error_log to see that the server has started and it's a right one. It should say something similar to:

  [Thu May 29 12:22:12 2003] [notice] Apache/2.0.46-dev (Unix)
  mod_perl/1.99_10-dev Perl/v5.9.0 mod_ssl/2.0.46-dev OpenSSL/0.9.7
  DAV/2 configured -- resuming normal operations

Registry Scripts

To enable registry scripts add to httpd.conf:

  Alias /perl/ /home/httpd/httpd-2.0/perl/
  <Location /perl/>
      SetHandler perl-script
      PerlResponseHandler ModPerl::Registry
      PerlOptions +ParseHeaders
      Options +ExecCGI
  </Location>

and now assuming that we have the following script:

  #!/usr/bin/perl
  print "Content-type: text/plain\n\n";
  print "mod_perl 2.0 rocks!\n";

saved in /home/httpd/httpd-2.0/perl/rock.pl. Make the script executable and readable by everybody:

  % chmod a+rx /home/httpd/httpd-2.0/perl/rock.pl

Of course the path to the script should be readable by the server too. In the real world you probably want to have a tighter permissions, but for the purpose of testing that things are working this is just fine.

Now restart the server and issue a request to http://localhost/perl/rock.pl and you should get the response:

  mod_perl 2.0 rocks!

If that didn't work check the error_log file.

For more information on the registry scripts refer to the ModPerl::Registry manapage. (XXX: on day there will a tutorial on registry, should port it from 1.0's docs).

Handler Modules

Finally check that you can run mod_perl handlers. Let's write a response handler similar to the registry script from the previous section:

  #file:MyApache/Rocks.pm
  #----------------------
  package MyApache::Rocks;
  
  use strict;
  use warnings;
  
  use Apache::RequestRec ();
  use Apache::RequestIO ();
  
  use Apache::Const -compile => qw(OK);
  
  sub handler {
      my $r = shift;
  
      $r->content_type('text/plain');
      print "mod_perl 2.0 rocks!\n";
  
      return Apache::OK;
  }
  1;

Save the code in the file MyApache/Rocks.pm, somewhere where mod_perl can find it. For example let's put it under /home/httpd/httpd-2.0/perl/MyApache/Rocks.pm, and we tell mod_perl that /home/httpd/httpd-2.0/perl/ is in @INC, via a startup file which includes just:

  use lib qw(/home/httpd/httpd-2.0/perl);
  1;

and loaded from httpd.conf:

  PerlRequire /home/httpd/httpd-2.0/perl/startup.pl

Now we can configure our module in httpd.conf:

  <Location /rocks>
      SetHandler perl-script
      PerlResponseHandler  MyApache::Rocks
  </Location>

Now restart the server and issue a request to http://localhost/rocks and you should get the response:

  mod_perl 2.0 rocks!

If that didn't work check the error_log file.

Troubleshooting

If after reading the complete installation and configuration chapters you are still having problems, take a look at the troubleshooting sections. If the problem persist, please report them using the following guidelines.

Maintainers

Maintainer is the person(s) you should contact with updates, corrections and patches.

  • Stas Bekman <stas (at) stason.org>

Authors

  • Stas Bekman <stas (at) stason.org>

Only the major authors are listed above. For contributors see the Changes file.