localfileproxy
Proxy local files to an online url.
Very useful in web services that uses files on a user's computer but don't want to require the user to upload anything.
- supports many clients
- simple api for programmatic usage
- supports client machines that don't have exposed ports (e.g. a laptop)
Web Server, Client Service, Browser Client
It can be a bit confusing to follow how this works because there are multiple clients involved. Here are the three roles:
- web server (Broker): AKA the localfileproxy server, this is a server on the internet that has an exposed port
- client service (Service): The client application that has access to the files
- browser client (Requester): This is a service that has URLs to the web server, but because it's a browser (or a different computer than the local client) it can't access the files directly. It will request the files from the web server.
Technical Details
All of this is facilitated via a ZeroMQ Majordomo-like pattern. Roughly, this is what happens...
- Start the Broker (the localfileproxy server on a Web Server)
- Client Service (Service) registers itself itself with the Web Server (Broker), establishing a socket connection
- Browser Client (Requester) makes request to Web Server (Broker)
- Web Server (Broker) sends a request to the Client Service (Service) over the socket
- Client Service (Service) answers the socket request with data from a file
- Web Server (Broker) receives data from Client Service (Service), and passes it to the Browser Client (Requester)
The Broker uses a ZeroMQ Router. The Service uses a ZeroMQ Dealer.