How to set #HOST# variable used in Chart template using Multiple Domains?

Question

I have a extended question to How can I set #HOST# variable referenced in the Chart template?
In addition to the Proxy layer, we are looking to use multiple sub-domain names into the same Oracle APEX instance (through the one DAD) each mapped to a different application id. Therefore I don't think the solution in the link will work for me - as this embeds a single domain name in the DADS.CONF.
Two questions:
- Is it possible to set the "HTTP_HOST" in "dads.conf" using an existing HTTP Header value? - my proxy can pass on the original domain as "HTTP_X_FORWARDED_HOST". So if it was possible to use (say: using whatever form/syntax of parameterisation is available) ?
>
PlsqlCGIEnvironmentList HTTP_HOST=%{HTTP_X_FORWARDED_HOST}
>
If it can then that would work for me. It would be great if modl_plsql handled this out of the box as I understand the "X-FORWARDED" approach is pretty standard in the proxy world including passing on original IP addresses. Hitting an phpinfo() site shows headers
>
HTTP_X_FORWARDED_FOR     192.168.2.100
HTTP_X_FORWARDED_HOST     dev.mycompany.com:443
HTTP_X_FORWARDED_SERVER     mycompany.com
>
- Alternatively is it possible in APEX environment to set the #HOST# from the HTTP Header "HTTP_X_FORWARDED_HOST" if it exists for all requests?
Thanks

Answer 1

Hi Donna,
changing the CGI environment variables HTTP_HOST, REQUEST_PROTOCOL and SERVER_PORT is the correct way how to resolve this, because it appears that your hiding the web server where you have installed mod_plsql or EPG by a different outside facing web server (also called reverse proxy). That's why APEX gets the host name, protocol and port of the internal web server, but should actually get the values of your reverse proxy web server. Can can fix that by changing the following CGI environment variables.
HTTP_HOST should just contain the domain name (no protocol or port). For example: www.oracle.com
REQUEST_PROTOCOL should contain http or https
SERVER_PORT should be the port for https
I don't want to add a new cgi variable called HOST because HOST sounds so generic and it might interfere with something else running in our environment. Or, I don't want to change the plsql cgi environment variable (such as HTTP_HOST) because many developers may use owa_util.get_cgi_env('HTTP_HOST') to get the current server. If the SERVER_PORT is part of the #HOST# then what could I change it to if it needs to be null. If you leave it blank, then the default SERVER_PORT comes from the CGI variables.The value of HTTP_HOST is wrong anyway and points to your internal web server, but I assume your developers actually want to get the host name of your external web server if they use it to generate absolute URLs. That's why I wouldn't bother and set it to the correct host name.
Regards
Patrick
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