Adding correlation headers via the InsightsMessageHandler would be great

[jesshannon]

It would be really useful if InsightsMessageHandler could add correlation headers, so user actions can be tracked across client and server when viewing on azure portal.

For example adding the request-id and traceparentid headers.

[dhindrik]

Great idea! I have also seen the need. I will add it during the weekend or next week.

[dhindrik]

@jesshannon I never used traceparent before, can you check my PR and see what you think?

[jesshannon]

@dhindrik It should be possible to use the existing dependency module already in AppInsights, it hooks into the DiagnosticSource events for HttpClient automatically and injects all the right headers.

Are you against the idea of including "Microsoft.ApplicationInsights.DependencyCollector" by default? Should it be an optional extra?

It would also listen for SqlClient diagnostics. Maybe we could extend sqlite-net-pcl to emit the same diagnostic events, so you could track it just like Sql Server.

[dhindrik]

I am not against to include it. I have started to investigate how to do it. But I cannot figure out how to add all the custom/global properties to it.

The TinyInsights feature of the DependencyFilter will not work.

But I guess it can be an option to use it so we not will break existing code. Something like this, #64

[jesshannon]

It looks like you're adding those properties directly on a single client instance after creating it. The dependency listeners create their own clients for the injected config.

If you set the properties from a custom ITelemetryInitializer instead, and register that in DI, then all the other modules will use that too. Just need to make sure you do it early enough for it to be injected into the config.

You can also use the ITelemetryInitializer to inspect and manipulate the telemetry before it's sent, so you could add special properties for certain telemetry types.