Configuring for the Apache Server

THE META-HTML LANGUAGE REFERENCE MANUAL

Server Configuration

[TOC]

FastCGI Apache

Configuring for the Apache Server

There are three possibilities to choose from when configuring your Apache server to work with Meta-HTML files:

You can run every document on your server through the Meta-HTML CGI Engine. While there is nothing horribly wrong with this, it is essentially equivalent to running the Meta-HTML server itself, so we do not highly recommend it.
You can run only Meta-HTML documents through the Meta-HTML CGI Engine, foregoing the ability to use statefull sessions with non-cookie capable browsers. If you never use statefull sessions, or, if you only have cookie-capable clients connecting to your server (e.g., Netscape, MSIE), this solution is completely reasonable, and totally painless.
You can run only Meta-HTML documents through the Meta-HTML CGI Engine, handling the case of non-cookie capable browsers co-existing with statefull sessions. This is our recommended configuration.

Step 1: Install the Engine:

In order for the Engine to operate under Apache, you must place it in your cgi-bin directory, and make it executable. For example, if your srm.conf file contained:

   ScriptAlias /cgi-bin/ /www/htdocs/cgi-bin/

then you would copy the Engine and its config file to that directory:

   user@host$ cp engine/engine /www/htdocs/cgi-bin/nph-engine
   user@host$ cp engine/engine.conf /www/htdocs/cgi-bin/

Step 2: Edit the `engine.conf` file:

Now edit the engine.conf file in /www/htdocs/cgi-bin, simply by reading the comments. For most installations, you won't actually need to change any of the parameters defined within -- the saavy site administrator may wish to add special behaviour, or to modify the existing behaviour.

Step 3: Edit the Apache `srm.conf` file:

Now edit the srm.conf for your Apache server. There are two possible edits:

Running Every Document Through the Engine
Add the following line before all of your other ScriptAlias lines:
```
     ScriptAlias / /cgi-bin/nph-engine
    
```
Running Only Meta-HTML Documents Through the Engine
Add the following lines to the srm.conf file, before all other ScriptAlias lines:
```
     AddType metahtml/interpreted .mhtml
     Action metahtml/interpreted /cgi-bin/nph-engine
    
```

Step 4: Compiling Apache 1.x With the Meta-HTML "mini-module":

If you want to make sure that non-cookie capable browsers can have statefull sessions, you will need to recompile your 1.x server with the Meta-HTML mini-module installed. Here is how to do that:

Place the following line in src/Configuration (in your Apache 1.x source tree)
```
     Module mhtml_module           mod_mhtml.o
```
Copy the mod_mhtml.c file to the src directory of your Apache 1.x source tree.
Reconfigure the compilation of your server by typing ./Configure from the src directory of your Apache 1.x source tree.
Recompile the Apache server by typing make, and then copy the httpd file to whereever you have installed the previous version of the Apache server.

That's it!

Congratulations! You have configured the Meta-HTML Engine to work with your Apache server!

So that you can see exactly what the mini-module does, I have included the source code below:

  /* mod_mhtml.c: -*- C -*-  Apache mini-module code for Meta-HTML. */

  #include "httpd.h"
  #include "http_config.h"
  #include "http_request.h"
  #include "http_core.h"
  #include "http_protocol.h"
  #include "http_log.h"
  #include "http_main.h"
  #include "util_script.h"

  /* If the URI starts with a string of digits, leave them there, but
     make the filename be everything after it. */
  static int
  translate_filename (struct request_rec *req)
  {
    register int i;
    int result = DECLINED;

    if ((req->uri != (char *)NULL) &&
        ((req->uri[0] == '/') && (isdigit (req->uri[1]))))
      {
        for (i = 1; isdigit (req->uri[i]); i++);


        /* If the URI contains a cookie, then gobble it, stuff it into
           req->subprocess_env, and move along. */
        if (req->uri[i] == '\0' || req->uri[i] == '/')
          {
            register int j;
            char *value = (char *)palloc (req->pool, 1 + i);
            table *page_env = req->subprocess_env;

            strncpy (value, req->uri + 1, i - 1);
            value[i - 1] = '\0';

            for (j = 0; req->uri[i] != '\0'; j++, i++)
              req->uri[j] = req->uri[i];

            req->uri[j] = '\0';

            /* Now stuff the value into a meaningful environment variable. */
            table_add (req->subprocess_env, "METAHTML_URL_COOKIE", value);
          }
      }

    return (result);
  }

  module mhtml_module =
  {
     STANDARD_MODULE_STUFF,
     NULL,                      /* initializer */
     NULL,                      /* dir config creater */
     NULL,                      /* dir merger --- default is to override */
     NULL,                      /* server config */
     NULL,                      /* merge server config */
     NULL,                      /* command table */
     NULL,                      /* handlers */
     translate_filename,        /* filename translation */
     NULL,                      /* check_user_id */
     NULL,                      /* check auth */
     NULL,                      /* check access */
     NULL,                      /* type_checker */
     NULL,                      /* fixups */
     NULL                               /* logger */
  };

Configuring for the Apache Server

Step 1: Install the Engine:

Step 2: Edit the engine.conf file:

Step 3: Edit the Apache srm.conf file:

Step 4: Compiling Apache 1.x With the Meta-HTML "mini-module":

That's it!

Step 2: Edit the `engine.conf` file:

Step 3: Edit the Apache `srm.conf` file: