3.2. Configuring Apache for the Eszter SB Application Engine

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You can use the Eszter SB Application Engine together with the Apache server. The reason to do this is that the engine is not a general purpose web server, like Apache. You want to have static pages, run Perl cgi scripts, PHP programs. These are not provided by the Eszter SB Application Engine. Therefore you need Apache.

Having Apache on your webserver you have two choices how to run ScriptBasic CGI programs.

You can run ScriptBasic programs as regular CGI programs. The command line version of the interpreter usually installed as `/usr/bin/scriba' is capable executing CGI programs. The CGI programs should have a starting line #! /usr/bin/scriba -c telling the UNIX operating system how to start ScriptBasic for the program. The option `-c' tells ScriptBasic that the program is executed in a CGI environment. If this option is used the error messages are HTML formatted and thus you can read it on the web browser. If you omit this option you will get "Internal Server Error" on the browser and you will be able to read the actual error in the Apache server error log.
Using the plain old CGI execution will execute each BASIC program in a newly created process. This means process starting overhead, all database connections are initiated by the program, and no memory stored session variables are available.
The other approach is to install and configure the Apache server including the modules PROXY and REWRITE. In this case the Eszter SB Application Engine runs the BASIC programs. This allows BASIC programs run in the same process in separate threads thus eliminating the overhead of process creation. This also allows access to memory stored session or application variables and database connection pooling. (Note however that the only database supported currently is MySQL and the external MySQL module does not have database connection pooling capability.)

These are standard modules, which are not compiled and configured with the default Apache installation. However they are needed by many installations and thus the Apache documentation contains examples how to compile and install Apache including these modules.

Once you successfully installed Apache including this module you have to alter the configuration file to tell Apache how to use these modules. To have the modules loaded into Apache you should have the two lines in your configuration file uncommented:

LoadModule proxy_module /usr/lib/apache/1.3/mod_proxy.so
LoadModule rewrite_module /usr/lib/apache/1.3/mod_rewrite.so

The actual path to the shared object files may be different. After the modules are configured you have to tell Apache that all URLs that have the file extension .bas should be proxy to the Eszter SB Application Engine. As an example I include here the lines of the configuration of my Linux station.

<VirtualHost 192.168.0.2>
ServerAdmin webmaster@scriptbasic.com
DocumentRoot /home/verhas/scriptbasic
ServerName www.scriptbasic
ServerAlias scriptbasic
ErrorLog /var/log/apache/scriptbasic/error.log
TransferLog /var/log/apache/scriptbasic/access.log
ScriptAlias /cgi-bin/ /home/verhas/scribas/
Alias /doc/ /home/verhas/scriptbasic/doc/
RewriteEngine on
RewriteLog /var/log/apache/rewrite.log
RewriteLogLevel 9
RewriteRule .*/redir/(.+)\.bas$ http://127.0.0.1:8080/cgi-bin/$1.bas [P]
</VirtualHost>

(This machine is no ever connected to the Internet, so you have no way to hack this Linux based on this information.)

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