It would be nice to follow a single schema for naming context
functions. In the trace package we followed the form FooFromContext
and ContextWithFoo. Do the same in the correlation package. The schema
WithFoo is mainly used for functions following the options pattern.
Not sure about a name of the NewContext function, though. For now I
have left it alone.
Co-authored-by: Rahul Patel <rghetia@yahoo.com>
Correlation context propagation shouldn't be a part of the trace
package - it is a different aspect of the propagation cross-cutting
concern.
This commit also adds a DefaultHTTPPropagator function for correlation
context propagation and makes the plugins use it.
Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>
* Remove binary propagators
They are in process of being dropped from the specification and we
haven't be using them anywhere in the project. Can reintroduce them
later.
* Rename Supplier to HTTPSupplier
The supplier is used only in HTTP propagators currently. It's not
clear if it will be useful for binary propagators if they get to be
specified at some point.
* Rework propagation interfaces
The biggest change here is that HTTP extractors return a new context
with whatever information the propagator is able to retrieve from the
supplier. Such interface does not hardcode any extractor's
functionality (like it was before by explicitly returning a span
context and correlation context) and makes it easy to chain multiple
propagators.
Injection part hasn't changed.
* Add Propagators interface
This interface (and its default implementation) is likely going to be
the propagation API used the most. Single injectors, extractors or
propagators are likely going to be used just as parameters to the
Option functions that configure the Propagators implementation.
* Drop noop propagator
It's rather pointless - just create an empty Propagators instance.
* Fix wrong name in docs
Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>
* Remove Vendor constants from tracing plugins
Unused. And confusing, since "ot" may mean "opentracing" as well.
* Simplify current span key declaration
No need for a block.
* Fix typo
Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>
* Rename distributedcontext package to correlation
Correlation is the name we agreed upon.
* Move trace propagators to api/trace
The trace propagators tests had to be moved to a testtrace subpackage
to avoid import cycles between api/trace and internal/trace.
Needed to shut up golint about stutter in trace.TraceContext -
TraceContext is a name of a W3C spec, so this stutter is
expected. It's certainly still better than golint's suggestion of
having trace.Context.
* Rename api/propagators to api/propagation
This package will not contain any propagators in the long run, just
the interface definitions.
Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>
* Merge propagation
Rename and merge propagation and api/propagation
to api/propagators.
Drop propagator suffix in general such that
TextFormatPropagator becomes TextFormat since
usage is propagators.TextFormat
fixes#311
* Rebase and godoc updates
* Revert go mod changes
* Replace carrier with supplier in godoc
