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Contents 1 Introduction 2 Pre-requisites 3 Enabling Ingres for Apache 4 Enabling Apache for Ingres 5 Verifying the setup 5.1 PHP 5.2 Python 6 Feedback

Introduction

Getting web applications to connect to Ingres via Apache on UNIX/Linux can be quite fiddly. Here is a simple guide on the setup steps needed to allow the Ingres PHP, Python and Ruby drivers to work with Apache on SuSE Linux.

Pre-requisites

It is assumed that you have the following installed:

• Ingres 2006 or newer ( Ingres >= 9.0.4 )
• openSuSE 11.0 or newer / SuSE Linux Enterprise Server / Desktop (SLES/SLED) 9
  • Earlier releases might also apply
• Apache 2.2.8
  • The steps here apply to other releases of Apache from 1.3 onwards
  • mod_env - An Apache module which modifies the environment which is passed to CGI scripts and SSI pages

Enabling Ingres for Apache

Any user that connects to Ingres must be a known (defined) user. Specifically a user account must be created within Ingres using CREATE USER .... In the case of web applications served by Apache, Tomcat or whatever, the server process owner is the user that Ingres will initially see. To determine the process owner for Apache execute the following:

ps -fe | grep apache | grep -v grep

On my system I get the following:

grant@esva-suse:~$ ps -fe | grep apache | grep -v grep
root     14056     1  4 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14060 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14074 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14076 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14077 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14078 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14079 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14080 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf
wwwrun   14081 14056  0 08:26 ?        00:00:00 /usr/sbin/httpd2-prefork -f /etc/apache2/httpd.conf

Which shows two user accounts for Apache. The root account can be ignored since it is a monitor/control process that starts up and shuts down servers as required. The processes run under the wwwrun' account will be used to connect to Ingres.

To add wwwrun to Ingres run the following, as the ingres administrator:

sql iidbdb <<EOSQL
create user wwwrun\g
commit\g
\q
EOSQL

You should see something similar to:

ingres@esva-suse:~> sql iidbdb <<EOSQL
> create user wwwrun\g
> commit\g
> \q
> EOSQL
INGRES TERMINAL MONITOR Copyright 2008 Ingres Corporation
Ingres Linux Version II 9.2.0 (int.lnx/141)NPTL login
Tue May 19 22:18:42 2009

continue
* Executing . . .

continue
* Executing . . .

continue
* Ingres Version II 9.2.0 (int.lnx/141)NPTL logout
Tue May 19 22:18:42 2009

Now the Ingres DBMS is setup for the Apache web server.

Enabling Apache for Ingres

1. Edit /usr/share/apache2/load_configuration to include the following:

    II_SYSTEM=/opt/Ingres/IngresII
    LD_LIBRARY_PATH=/opt/Ingres/IngresII/ingres/lib
    ODBCSYSINI=/opt/Ingres/IngresII/ingres/files
    export II_SYSTEM LD_LIBRARY_PATH ODBCSYSINI

   Note - ODBCSYSINI is only needed for the Python driver
2. Create a new config file, /etc/apache2/conf.d/ingres.conf, adding the following:

PassEnv II_SYSTEM LD_LIBRARY_PATH ODBCSYSINI

3. Restart apache: /etc/init.d/apache2 restart

Verifying the setup

To see that the environment variables are visible the following code snippets can be executed through Apache through PHP and mod_python.

PHP

• Code:

<?php
 echo "II_SYSTEM is :" .$_SERVER["II_SYSTEM"] . "<br/>\n";
 echo "LD_LIBRARY_PATH is :" .$_SERVER["LD_LIBRARY_PATH"] . "<br/>\n";
?>

• Sample Output:

II_SYSTEM is :/opt/Ingres/II
LD_LIBRARY_PATH is :/lib:/usr/lib:/usr/local/lib:/opt/Ingres/II/ingres/lib:/opt/Ingres/II/ingres/lib/lp32

Python

• Code, save as env.py:

from mod_python import apache

def environment(req):
    req.content_type = "text/html"
    req.add_common_vars()
    env_vars = req.subprocess_env.copy()

    req.write('<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">')
    req.write('<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">')
    req.write('<head><title>mod_python.publisher</title></head>')
    req.write('<body>')
    req.write('<h1>Environment Variables</h1>')
    req.write('<table border="1">')
    req.write('<tr><td>%s</td><td>%s</td></tr>' % ("II_SYSTEM", env_vars['II_SYSTEM']))
    req.write('<tr><td>%s</td><td>%s</td></tr>' % ("LD_LIBRARY_PATH", env_vars['LD_LIBRARY_PATH']))
    req.write('</table>')
    req.write('</body>')
    req.write('</html>')

• Ouput from http://localhost/env.py/environment:

Environment Variables
II_SYSTEM	/opt/Ingres/II
LD_LIBRARY_PATH	/lib:/usr/lib:/usr/local/lib:/opt/Ingres/II/ingres/lib:/opt/Ingres/II/ingres/lib/lp32

Feedback

If you have any feedback please contact Grant Croker.