Disclaimer, I am technical support and sysadmin for my company, not a developer. I'm not after the specifics, simply an idea if what I'd like to acheive is possible or not.
We host hundreds of instances of our in-house classic ASP legacy ecommerce software application and due to countless customisations by clients and ourselves, version management is nightmarish, custom code can't be managed and we've given up releasing new features and mass deploying bug fixes due to the inability to track who needs what patches where.
Parellel to this question I am making management scripts to better automate this though.
What however I'd really like to do is using the miniumum possible effort, port the application code (not the database) to a single code base. Questions I have:
Can ASP relatively effeciently handle connecting to different databases depending on the host header being called? I plan some basic extension to the routine, get hostheader lookup up db credentials in metadb, set application connection string accordingly logic.
The application writes a few files to the webserver from the database for caching purposes, I'd like to handle this by emulating this behaviour by writing it to something like /masterapp/customer1/specificfile.htm then changing the references to /specificfile.htm in the code to more like /masterapp/shop name/specificfile.htm. Obviously the routines that write specificfile.htm would write to the new location accordingly. Does this seem reasonable?
Other webserver-bound store specific contents like images and csv files I need to keep working without URLs changing ideally, can ASP employ logic to redirect get requests for /images/example.jpg to either /masterapp/shop name/images/example.jpg or /shopname/images/example.jpg depending again on host header? Or could that be done via isapirewrite? (which we already use)
I think these are the biggest challenges. I don't need a complete project plan of how to implement each of these things, I just want to know if it's possible. If the answer is 'yes' I should be able to sell my bosses on the development due to saving support time and our in-house developers could hopefully manage this.