copy tags from the context into spans

[ivantopo]

Once #552 is merged we will be able to copy tags from incoming HTTP requests into the HTTP server spans, but it is something very specific to the server instrumentation. I'm thinking that it might be useful to define this behavior as a more general tracer behavior, in which upon starting or finishing a Span a certain number of tags can be copied into the Span from the current context... this would ensure that certain information can be stored on all Spans created by an instrumented app, regardless of who created the Span (manually or via automatic instrumentation).

[codefromthecrypt]

in brave we have a finishedspanhandler now which allows you to copy things into the span from the context. this assumes whatever you wanted isnt removed between start and finish which is likely ok. this stage is before a span is reported. from a user pov a hook that has an expression based on a context (source) and expression on the span (sink) would let you copy anything. doing just some tags is likely simpler both to implement and understand.

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On Fri, 12 Oct 2018, 21:04 Ivan Topolnjak, ***@***.***> wrote: Once #552 <#552> is merged we will be able to copy tags from incoming HTTP requests into the HTTP server spans, but it is something very specific to the server instrumentation. I'm thinking that it might be useful to define this behavior as a more general tracer behavior, in which upon starting or finishing a Span a certain number of tags can be copied into the Span from the current context... this would ensure that certain information can be stored on all Spans created by an instrumented app, regardless of who created the Span (manually or via automatic instrumentation). — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#556>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAD61_asoA3Kuv5oFDZROEfROp2L0chrks5ukJNlgaJpZM4XZb4a> .