IdentityServer 4 with ARR (Application Request Routing)

Question

I am trying to get IdentityServer 4 running in a two-node ARR setup. I have other two-node Web applications configured but IdentityServer doesn't want to play nice. The servers are setup for HTTPS only. When I had it in a single site everything was fine, and all requests were https://... But in the ARR setup the requests start like:

https://identityserver.local/.well-known/openid-configuration http:/identityserver.local/connect/authorize?client_id=....

The second request results in a 404. When I have it as a regular single site, that second request is:

https:/identityserver.local/connect/authorize?client_id=....

Why is it http instead of https when running with ARR?

Answer 1

The solution for this one 2-step: First I fixed the Forwarded headers:

services.Configure<ForwardedHeadersOptions>(options =>
{
    options.ForwardedHeaders = ForwardedHeaders.XForwardedProto;
});

Next, configure data protection so that the encryption keys are shared by different instances of the app.

services.AddDataProtection()
        .SetApplicationName("MyAspNetCoreSample")
        .PersistKeysToFileSystem(new DirectoryInfo(@"path\to\shared\folder"));

Hope this helps someone.