New central config options: CaptureHeaders, LogLevel, SpanFramesMinDuration, StackTraceLimit

[gregkalapos]

These 4 configs are not yet supported by .NET, but they are already added in Kibana.

Given we already have the infrastructure, let's add these 4 and make them also runtime changeable.

capture_headers
log_level
span_frames_min_duration
stack_trace_limit

[gregkalapos]

Note to future self: Don't forget to update the docs ;)

[gregkalapos]

Big progress was made on this by @vhatsura in #820 👏

Missing part to close this:
LogLevel does not work yet.

• We should make sure our loggers read the value that we fetch from central config
• We should also think about how this integrates with .NET Core logging (e.g. do we really want to override the log level defined in appsettings.json or elsewhere, etc.)

[vhatsura]

@gregkalapos,
(I've tried to resolve it, at least, for console logger, but it instantiates before remote configuration and used by central config fetcher itself. Looks like we need to add a new method on IApmLogger interface, smth like SetLogLevel. WDYT?
As for

We should also think about how this integrates with .NET Core logging

I'd say, we don't need to do it, due to log level is defined on common logging configuration.

[gregkalapos]

@gregkalapos,
(I've tried to resolve it, at least, for console logger, but it instantiates before remote configuration and used by central config fetcher itself. Looks like we need to add a new method on IApmLogger interface, smth like SetLogLevel. WDYT?
As for

We should also think about how this integrates with .NET Core logging

I'd say, we don't need to do it, due to log level is defined on common logging configuration.

Looks like we need to add a new method on IApmLogger interface, smth like SetLogLevel. WDYT?

Well, it'd be really nice to avoid it - otherwise all implementors need to implement it - and I know for our IIS module it's common that people redirect logs by implementing IApmLogger - for them this would mean a build error. This would be especially less nice if all the benefit would be that our Console Logger uses it, but e.g. in ASP.NET Core we ignore this.

[gregkalapos]

With #1096 this is done.