[Unified] Error pre-validating against SSO service

Steps To Reproduce

Follow the tutorial on https://bitwarden.com/help/saml-keycloak/ (Needs updating)
Open incognito/private window
Try to login via SSO

Expected Result

Should redirect to Keycloak for authentication and redirect back (I'm kerberos enabled)

Actual Result

Red error box pops up on screen saying Error pre-validating against SSO service.

Loading spinner keeps spinning.

Screenshots or Videos

Additional Context

Logs from docker:

fail: Bit.Identity.Controllers.SsoController[0] => SpanId:5f02e6c46dc1eb02, TraceId:fd52673c93ea7b154b0fe56161b4ab48, ParentId:0000000000000000 => ConnectionId:0HMSU72UBRP6A => RequestPath:/identity/account/prevalidate RequestId:0HMSU72UBRP6A:00000002 => Bit.Identity.Controllers.SsoController.PreValidate (Identity) Error pre-validating against SSO service System.Net.Http.HttpRequestException: Cannot assign requested address (localhost:5007) ---> System.Net.Sockets.SocketException (99): Cannot assign requested address at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken) at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token) at System.Net.Sockets.Socket.g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) --- End of inner exception stack trace --- at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(HttpRequestMessage request) at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.GetHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken) at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken) at Microsoft.Extensions.Http.Logging.LoggingHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) at Microsoft.Extensions.Http.Logging.LoggingScopeHttpMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) at System.Net.Http.HttpClient.g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken) at Bit.Identity.Controllers.SsoController.PreValidate(String domainHint) in /source/src/Identity/Controllers/SsoController.cs:line 59

Githash Version

9b007586-dirty

Environment Details

Server Type: VPS (Vultr)
vCPU/s: 1 vCPU
RAM: 2048.00 MB
Storage: 50 GB NVMe
IPv4 Address: True
IPv6 Address: True
Operating System: Fedora 38 Minimal (No GUI)
Container: Docker (Standalone)
Firewall: CSF Firewall
DNS Resolver: Unbound
Additional Software: Grafana Agent (Logging & Monitoring)

Database Image

Seperate VPS same specs as Environment Details without Docker PostgreSQL version 15.1-2

Issue-Link

https://github.com/bitwarden/server/issues/2480

Issue Tracking Info

[X] I understand that work is tracked outside of Github. A PR will be linked to this issue should one be opened to address it, but Bitwarden doesn't use fields like "assigned", "milestone", or "project" to track progress.

bitwarden / server