I have an issue running an .NET Core worker service on an On-Premise environment, that blocks by default all outgoing request. The service is trying to send push notifications via the FirebaseAdmin package (https://github.com/Firebase/firebase-admin-dotnet) and on our test environment, that is hosted in azure, everything works fine.
I have no idea which URLs need to opened up in the firewall so get the notifications going. The only error message I get is not helping.
2020-04-17 12:42:19.979 +02:00 [ERR] Error sending notification 13f54141-0455-4829-afa0-172e7963965e
System.Net.Http.HttpRequestException: No such host is known.
---> System.Net.Sockets.SocketException (11001): No such host is known.
at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken)
--- End of inner exception stack trace ---
at Google.Apis.Http.ConfigurableMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpClient.FinishSendAsyncBuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
at Google.Apis.Auth.OAuth2.Requests.TokenRequestExtenstions.ExecuteAsync(TokenRequest request, HttpClient httpClient, String tokenServerUrl, CancellationToken taskCancellationToken, IClock clock)
at Google.Apis.Auth.OAuth2.ServiceAccountCredential.RequestAccessTokenAsync(CancellationToken taskCancellationToken)
at Google.Apis.Auth.OAuth2.TokenRefreshManager.RefreshTokenAsync()
at Google.Apis.Auth.OAuth2.TokenRefreshManager.ResultWithUnwrappedExceptions[T](Task`1 task)
at Google.Apis.Auth.OAuth2.TokenRefreshManager.<>c.<GetAccessTokenForRequestAsync>b__10_0(Task`1 task)
at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj)
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location where exception was thrown ---
at Google.Apis.Auth.OAuth2.TokenRefreshManager.GetAccessTokenForRequestAsync(CancellationToken cancellationToken)
at Google.Apis.Auth.OAuth2.ServiceAccountCredential.GetAccessTokenForRequestAsync(String authUri, CancellationToken cancellationToken)
at Google.Apis.Auth.OAuth2.ServiceCredential.InterceptAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at Google.Apis.Http.ConfigurableMessageHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpClient.FinishSendAsyncBuffered(Task`1 sendTask, HttpRequestMessage request, CancellationTokenSource cts, Boolean disposeCts)
at FirebaseAdmin.Util.ErrorHandlingHttpClient`1.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
at FirebaseAdmin.Util.ErrorHandlingHttpClient`1.SendAndReadAsync(HttpRequestMessage request, CancellationToken cancellationToken)
I had a look into the google-api-dotnet package but it seems like they are using their own logging system, which does not show up in our log files.
Any one has an idea how to get further information on what host gets blocked here?
You will likely have to open up: