dotnet core app api do not keep running on kubernetes - kubernetes

Question

I'm setting a dotnet core app into kubernetes cluster and i getting error "Unable to start kestrel".
Dockerfile is working ok on local machine.
at Microsoft.AspNetCore.Hosting.ListenOptionsHttpsExtensions.UseHttps(ListenOptions listenOptions)
at Microsoft.AspNetCore.Hosting.ListenOptionsHttpsExtensions.UseHttps(ListenOptions listenOptions, Action`1 configureOptions)
For more information on configuring HTTPS see https://go.microsoft.com/fwlink/?linkid=848054.
To generate a developer certificate run 'dotnet dev-certs https'. To trust the certificate (Windows and macOS only) run 'dotnet dev-certs https --trust'.
Unhandled Exception: System.InvalidOperationException: Unable to configure HTTPS endpoint. No server certificate was specified, and the default developer certificate could not be found.
at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding)
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context)
at Microsoft.AspNetCore.Hosting.ListenOptionsHttpsExtensions.UseHttps(ListenOptions listenOptions)
at Microsoft.AspNetCore.Hosting.ListenOptionsHttpsExtensions.UseHttps(ListenOptions listenOptions, Action`1 configureOptions)
For more information on configuring HTTPS see https://go.microsoft.com/fwlink/?linkid=848054.
To generate a developer certificate run 'dotnet dev-certs https'. To trust the certificate (Windows and macOS only) run 'dotnet dev-certs https --trust'.
System.InvalidOperationException: Unable to configure HTTPS endpoint. No server certificate was specified, and the default developer certificate could not be found.
Unable to start Kestrel.
My dockerfile:
[...build step]
FROM microsoft/dotnet:2.1-aspnetcore-runtime
COPY --from=build-env /app/out ./app
ENV PORT=5000
ENV ASPNETCORE_URLS=http://+:${PORT}
WORKDIR /app
EXPOSE $PORT
ENTRYPOINT [ "dotnet", "Gateway.dll" ]
I expected application started successfully but i getting this error "unable to start kestrel".
[UPDATE]
I've removed https port from app and tried again without https but now application just start and stop without any error or warning. Container log bellow:
Running local using dotnet run or building image and running from container, everything work. Application just shut down into kubernetes.
I am using dotnet core 2.2
[UPDATE]
I've generated a cert, added in project, setup in kestrel and i got same result. Localhost using docker imagem it work, but in kubernetes (google cloud), it just shutdown immediately after it started.
localhost:
$ docker run --rm -it -p 5000:5000/tcp -p 5001:5001/tcp juooo:latest
warn: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[35]
No XML encryptor configured. Key {f7808ac5-0a0d-47d0-86cb-c605c2db84a3} may be persisted to storage in unencrypted form.
warn: Microsoft.AspNetCore.Server.Kestrel[0]
Overriding address(es) 'https://+:5001, http://+:5000'. Binding to endpoints defined in UseKestrel() instead.
Hosting environment: Production
Content root path: /app
Now listening on: https://0.0.0.0:5001
Application started. Press Ctrl+C to shut down.

Answer 1

I found a event log with a kubernetes error saying that kubernetes was unable to hit (:5000/). So i tried create a controller targeting root application (because it's a api, so don't have a root like a web app) and it worked.

Answer 2

The problem seems to be with the SSL certificate not being correctly configured while creating docker image. On dev machine,it will be using the developer certificate however on other machines it should be stored somewhere. Check this

Answer 3

I am pretty sure you need to open up a firewall rule to run on any port other than 80, something like:
gcloud compute firewall-rules create test-node-port --allow tcp:5000
Taken from kubernetes how-to located here: https://cloud.google.com/kubernetes-engine/docs/how-to/exposing-apps