Example about "Serve the index page from the BFF host"

[andrekiba]

Thanks in advance.

Is it possible to have an example about the Serve the index page from the BFF host ?
I'm thinking if using Yarp to serve the index.html could be a way or maybe using the UseStaticFiles() with a custom IFileProvider that pulls the index.html from the CDN.
Do you have a suggestion?

[khalidabuhakmeh]

@andrekiba The BFF host is a regular ASP.NET Core application, so you can add a minimal API endpoint that can proxy information from your CDN through the BFF Host.

app.Map("/", (IWebHostEnvironment env) =>
{
    // get web content root
    var webRootPath = env.WebRootPath;
    // read the file from anywhere, including a CDN
    var file = File.OpenRead(Path.Combine(webRootPath, "_index.html"));
    return Results.Stream(file, "text/html");
});

If you have no static files on the host, you can remove the static files middleware.

[andrekiba]

Thanks @khalidabuhakmeh yesterday I was trying with something like this for a test.

[khalidabuhakmeh]

Do you only need to serve the index.html file or do you need all the static files served through the proxy?

[khalidabuhakmeh]

YARP does have a feature called "Direct Forwarding," which you can read about here.

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/servers/yarp/direct-forwarding?view=aspnetcore-9.0

It's similar to the concept from above but built into YARP directly. It should let you handle all the files in a CDN.

[andrekiba]

Thanks again @khalidabuhakmeh, the idea is to serve just the index.html (maybe from an azure blob storage, where all other chunks are)
With the middleware I have to use an httpClient to download and serve the content, may YARP does this better?
I'll look at the direct forwarding.
As I said I'm just doing some tests to understand which will be a good way to go and I have to learn how YARP works.