I'm trying to write a front end to an API service with Node JS (with which I am a relative beginner).
I'd like to be able to have a user point their browser at my node server and make a request. The node script would modify the input to the request, call the api service, then modify the output and pass back to the user.
I like the solution here (with Express JS and node-http-proxy) as it passes the cookies and headers directly from the user through my site to the api server.
proxy request in node.js / express
I see how to modify the input to the request, but i can't figure out how to modify the response. Any suggestions?
Harmon is designed to plug into node-http-proxy https://github.com/No9/harmon It uses trumpet and so is stream based to work around any buffering problems. It uses an element and attribute selector to enable manipulation of a response.
This can be used to modify output response.
See here: https://github.com/nodejitsu/node-http-proxy/issues/382#issuecomment-14895039
transformer-proxy could be useful here. I'm the author of this plugin and I'm answering here because I found this page when looking for the same question and wasn't satisfied with harmon as I don't want to manipulate HTML.
Maybe someone else is looking for this and finds it useful.
http-proxy-interceptor is a middleware I wrote for this very purpose. It allows you to modify the http response using one or more transform streams. There are tons of stream-based packages available (like trumpet, which harmon uses), and by using streams you can avoid buffering the entire response.
来源：https://stackoverflow.com/questions/13596942/using-node-js-to-proxy-http-and-modify-response