Broken app startup when Overriding Microsoft logs

[4wakened5leeper]

I have a strange behaviour when I start a new Asp .Net Core project in VS2019, with Docker support on Linux. I add the support of docker-compose, and update the default program.cs with the one in the EarlyInitializationSample. (With Serilog.AspNetCore 3.0 nuget package)
I start the app, everything works fine, it launches my browser on the WeatherForecastController (the demo controller from the Visual Studio template).

If I add a filter in the logger configuration (.MinimumLevel.Override("System", LogEventLevel.Warning)), it still works as expected.

BUT ! If I replace System by Microsoft (.MinimumLevel.Override("Microsoft", LogEventLevel.Warning)), the application start, but seems to stop loading stuff in the middle of the startup process, and it doesn't launch my browser.

My app seems to respond normally, but I fear it could hide something wierd...

[nblumhardt]

Very strange! I know it's easy for me to say :-) but I think this is unlikely to be directly caused by Serilog (chances are that the odd logging behavior is a symptom of some other problem, perhaps missing assemblies in the deployment, mismatched target/runtime versions, or a broken install of something in the image.. the possibilities are pretty broad).

If you find more details or figure out how to reproduce it with a File > New Project-style app and container image, it would be great to learn more, but there's not a lot of chance we can help at this stage, sorry.

[4wakened5leeper]

Yes, as I wrote in my previous post, it's very quick and straightforward to reproduce, here are the detailed steps:

• In VS2019, Create a new project / with ASP.NET Core Web Application template / clic Create
• In the wizard, select ASP.NET Core 3.0 / API / No Authentication / Uncheck Configure for HTTPS / Check Enable Docker Support for Linux / clic Create
• In VS, right clic on the csproj / Add / Container Orchestrator Support... / Select Docker-Compose / Select Linux / clic OK
• right clic on Dependencies / Manage Nuget Packages / Install Serilog.AspNetCore nuget package (v3.0.0)
• copy the content of EarlyInitializationSample Program.cs into your Program.cs
• in Program.cs, during the LoggerConfiguration, add .MinimumLevel.Override("System", LogEventLevel.Warning) just after .ReadFrom.Configuration(Configuration)
• clic on ▶️ Docker Compose: the app is deployed on Docker, and VS launch the browser on http://localhost:XXXXX/weatherforecast

Here, everything works fine.

• Now, replace System by Microsoft in .MinimumLevel.Override("System", LogEventLevel.Warning)
• clic on ▶️ Docker Compose: the app is deployed on Docker, but suddently, something stop working during the initialization, VS don't launch the browser.

[nblumhardt]

Thanks for the follow-up 👍

Just to clarify, the problem is just that VS does not launch the browser? If so, it might be that VS is waiting to see some specific (Microsoft.*) log output as an indication that the process is ready.

[4wakened5leeper]

Indeed, it could just be a VS issue as it's the only visible problem...
But it works with .Net Core 2.2, so I'll try with the next release of .Net Core 3 !

[nblumhardt]

I'll close this for now, but if you end up with more information/any data that points to an issue in Serilog, please feel free to jump back in. Thanks, Flavien!

[tbraz]

Thanks for the follow-up 👍

Just to clarify, the problem is just that VS does not launch the browser? If so, it might be that VS is waiting to see some specific (Microsoft.*) log output as an indication that the process is ready.

I've encountered the same issue, and after reading this thread and your comment in particular I made some testing with the logging output.

It seems indeed that VS is waiting on a specific output from Microsoft.Hosting.Lifetime to launch the browser.

[INF][Microsoft.Hosting.Lifetime] Now listening on: https://[::]:443
[INF][Microsoft.Hosting.Lifetime] Now listening on: http://[::]:80
[INF][Microsoft.Hosting.Lifetime] Application started. Press Ctrl+C to shut down.

Those are the first log outputs from that Namespace that appear in the logs and if I silence them (change the log level to something higher than Information) the browser won't launch.

There is no issue what so ever with Serilog.

[dev-thinks]

Yes. encountered this same case today when running with linux docker container. glad i found this information to confirm it. Thanks.

[dazinator]

I just hit this when my application was deployed to Azure Web App for Containers. Azure starts the container, and then just waits for ages to detect whether it has started. What is the solution - can we override microsoft in general but just allow those specific entries through somehow?