YARP service discovery broke for preview 5 & 6 ?

[swegele]

This was working at preview 4. Since 5 and 6 the wrong uri is returned. It returns the one for blazor website (itself) not the webapi.

This is from program.cs in the blazor web app (server side)

app.MapForwarder($"/{-mypathhere-}{{**catch-all}}", "https://mywebapi", transformBuilder =>
{                
    transformBuilder.AddRequestTransform(LocalAddRequestTransform);
}).RequireAuthorization();

program.cs from AppHost

var mywebapi = builder.AddProject<MyWebAPI>("mywebapi")
    ...

var websitemain = builder.AddProject<WebsiteMain>("websitemain")
    .WithReference(mywebapi);

The following are the actual URLs:
mywebapi = https://localhost:7182
websitemain = https://localhost:7237

When the YARP does it's thing, it sends the request to https://localhost:7237/api/projects...
That is wrong.
It should be (and was) https://localhost:7182/api/projects...

So to fix it for now I have to manually enter this and it works:

app.MapForwarder($"/{-mypathhere-}{{**catch-all}}", "https://localhost:7182", transformBuilder =>
{                
    transformBuilder.AddRequestTransform(LocalAddRequestTransform);
}).RequireAuthorization();

I didn't notice any new requirements to make service discovery work in the upgrade docs but maybe i missed something.

[DamianEdwards]

@ReubenBond ?

[ReubenBond]

I'm trying to spot the difference between this and what we have in our samples.

Do you have the call to builder.Services.AddHttpForwarderWithServiceDiscovery(); in your WebsiteMain project, @swegele?

[swegele]

Yep program.cs of the blazor server web app...nestled in here between fluent and http...

builder.Services.AddFluentUIComponents();
builder.Services.AddHttpForwarderWithServiceDiscovery();
builder.Services.AddHttpContextAccessor();

I'm trying to spot the difference between this and what we have in our samples.

IKR - I've been scouring the lines too looking for something as I figured it had to be my fault...surely y'all would have seen such an obvious issue by now. The weird thing is that it actually does a replacement/lookup - it just gets the wrong one.

[swegele]

The only diff I see between eshop and mine is that I use the transformBuilder => action overload

Eshop

app.MapForwarder("/product-images/{id}", "http://catalog-api", "/api/v1/catalog/items/{id}/pic");

Mine

async ValueTask LocalAddRequestTransform(RequestTransformContext context)
{
    var accessToken = await context.HttpContext.GetTokenAsync("access_token");
    context.ProxyRequest.Headers.Authorization = new("Bearer", accessToken);
}


app.MapForwarder($"/api/projects/{{**catch-all}}", "https://mywebapi", transformBuilder =>
{                
    transformBuilder.AddRequestTransform(LocalAddRequestTransform);
}).RequireAuthorization();

That local function is for re-use because I currently have 4 different calls to MapForwarder

• users api
• projects api
• organization api
• signalr hub

[swegele]

This may or may not still be an issue, and if it is then others will find it and perhaps report it in a better way.

For now I simply changed to using the ToString() method of the URI used for my .AddHttpClient((...) methods.
Service discovery is working fine for those so why not just use that.

var myWebAPIBaseUri = new Uri("https://mywebapi");
and
myWebAPIBaseUri.ToString() in the .MapForwarder(...) methods.