Allow an array-style config format for Serilog:MinimumLevel:Override

At the moment, the way you specify Serilog’s minimum level overrides in configuration is in the following format:

"MinimumLevel": {
	"Default": "Information",
	"Override": {
		"Microsoft.AspNetCore.Mvc.Infrastructure": "Debug",
		"Microsoft": "Warning",
		"Microsoft.Hosting.Lifetime": "Information",
		"Microsoft.AspNetCore.Authentication": "Verbose",
	}
}

The source context (or ‘namespace’) is specified in the setting name, rather than a value. The trouble with this is that not all configuration providers lend themselves to having long, complex configuration key names. For example, I’ve tried to configure the equivalent to this on an Azure web app (using the double-underscore namespace separator as a replacement for the colon), and the best I could get to was:

"Serilog:MinimumLevel:Override:Microsoft_AspNetCore_Mvc_Infras": "Debug"

On my local machine, which is using appsettings.json, this is how it (correctly) looks:

"Serilog:MinimumLevel:Override:Microsoft.AspNetCore.Mvc.Infrastructure": "Debug"

The dots have been replaced with underscores, and more importantly there is a very restrictive length limit on config key names from these environment variables. So I think the solution is not to try and put complex/long information like a namespace in the key name, but as a key value. Thus, I propose that Serilog support the following syntax for minimum level overrides:

"MinimumLevel": {
	"Default": "Information",
	"Override": [
		{
			"SourceContext": "Microsoft.AspNetCore.Mvc.Infrastructure",
			"Level": "Debug"
		},
		{
			"SourceContext": "Microsoft",
			"Level": "Warning"
		},
		{
			"SourceContext": "Microsoft.Hosting.Lifetime",
			"Level": "Information"
		},
		{
			"SourceContext": "Microsoft.AspNetCore.Authentication",
			"Level": "Verbose"
		}
	]
}

When Override is an array, it takes a set of objects with SourceContext/Level that specify the override level for the given source context. This results in the following kind of config structure, which works even with config providers that have restrictive key names:

"Serilog:MinimumLevel:Override:0:SourceContext": "Microsoft.AspNetCore.Mvc.Infrastructure"
"Serilog:MinimumLevel:Override:0:Level": "Debug"

[skomis-mm]

New syntax other than adding more verbosity won’t do any better for environment variables. For one level override: MinimumLevel__Override__0__SourceContext=Microsoft.AspNetCore.Mvc.Infrastructure MinimumLevel__Override__0__Level=Debug

1. Still need to use underscores for some platforms
2. Need to use array indexes elements in the key names which are fragile to use
3. 2 variables for one override instead of 1

We have an old issue to overcome current current syntax and simplify it, not to add complexity to it.

[nblumhardt]

I think any issue Serilog suffers here is going to be shared by Microsoft.Extensions.Logging, which uses the same layout for overrides, so hopefully the Azure web app limitation will be spotted and lifted by the good folks at Microsoft. Raising an issue with them might speed this along, @jez9999.

Adding more variations to the configuration syntax makes it more complicated to define, document, and learn, hence @skomis-mm’s concern about UX, I think.

We don’t have the time here for the “nonsense”, “so what?” combative style of communication; it drains the energy out of open source projects. I’ve responded to similar recent comments here and here. Life’s too short for more of this, let’s start afresh if necessary, closing.