fix: deprecate api rack env getter (#1042)

* fix: deprecate api rack env getter

* fix: reduce spam level of deprecation warning

Author: robertlaurin

api/lib/opentelemetry/context/propagation.rb

@@ -67,9 +67,13 @@ def text_map_setter
         TEXT_MAP_SETTER
       end
 
+      # @deprecated Use the rack env getter found in the
+      # opentelemetry-common gem instead.
       # Returns a {RackEnvGetter} instance suitable for reading values from a
       # Rack environment.
       def rack_env_getter
+        OpenTelemetry.logger.warn('OpenTelemetry::Context::Propagation.rack_env_getter has been deprecated \
+          use OpenTelemetry::Common::Propagation.rack_env_getter from the opentelemetry-common gem instead.')
         RACK_ENV_GETTER
       end
     end

api/lib/opentelemetry/context/propagation/rack_env_getter.rb

@@ -7,6 +7,9 @@
 module OpenTelemetry
   class Context
     module Propagation
+      # @deprecated Use the rack env getter found in the
+      # opentelemetry-common gem instead.
+
       # The RackEnvGetter class provides a common methods for reading
       # keys from a rack environment. It abstracts away the rack-normalization
       # process so that keys can be looked up without having to transform them

propagator/jaeger/test/text_map_propagator_test.rb

@@ -132,7 +132,7 @@ def extracted_context_must_equal_parent_context(header)
       context = propagator.extract(
         carrier,
         context: parent_context,
-        getter: OpenTelemetry::Context::Propagation.rack_env_getter
+        getter: OpenTelemetry::Common::Propagation.rack_env_getter
       )
       span_context = OpenTelemetry::Trace.current_span(context).context
       _(span_context.hex_trace_id).must_equal('80f198ee56343ba864fe8b2a57d3eff7')