Redirect outgoing external asset requests to local filesystem with NodeJS - html

Question

Let's say we have a request to an S3 bucket to get an image:
<img src="https://s3-us-west-2.amazonaws.com/{BUCKET}/logo.png" />
I need to work on this project without having access to the internet, so within my Express server, I need to find a way to redirect all requests from https://s3-us-west-2.amazonaws.com/{BUCKET} to ~/Desktop/project/{BUCKET}.
Is there a way to do this via proxying, or would it be a better idea to cut a new branch and replace all external asset links with local file locations?

Answer 1

You would have something get something like this in your network panel
"https://s3-us-west-2.amazonaws.com/{BUCKET}/logo.png"
You can basically remove all "http://s3-us-west-2.amazonaws.com"
And lets say you run it on localhost:3000, your request will look like http://localhost:3000/{BUCKET}/logo.png
You can add following lines in your express server.
var request = require('request');
var proxy = true //if running locally else false
app.get('/{BUCKET}/logo.png', function (req,res) {
if (proxy)
res.sendFile('/home/Desktop/project/' + req.url)
else {
var options = {url : 'http://s3-us-west-2.amazonaws.com' +req.url,
method: 'GET'};
req.pipe(request(options)).pipe(res);
}
)}
The problem with this may be that for every asset it requests from s3 it will always go through your express server and the load of getting the assets will come on express server. You can do it for development but it is not recommended for production.
So for the final deploy you can put all the "http://s3-us-west-2.amazonaws.com" again.
If you don't want to do it programmatically, you can use proxy tools like charles or fiddler. They capture all the traffic from your system. You can create rules for particular requests or set of requests to fetch from local instead of s3.