Merge pull request #233 from tsloughter/baggage-encoding

url encode baggage keys and values

Author: tsloughter

README.md

@@ -9,6 +9,14 @@ OpenTelemetry stats collection and distributed tracing framework for Erlang.
 
 Requires OTP 21.3 or above.
 
+## Contacting Us
+
+We hold regular meetings. See details at [community page](https://github.com/open-telemetry/community#special-interest-groups).
+
+We use [GitHub Discussions](https://github.com/open-telemetry/opentelemetry-erlang/discussions) for support or general questions. Feel free to drop us a line.
+
+We are also present in the #otel-erlang-elixir channel in the [CNCF slack](https://slack.cncf.io/). Please join us for more informal discussions.
+
 ## Design
 
 The [OpenTelemetry specification](https://github.com/open-telemetry/opentelemetry-specification) defines a language library as having 2 components, the API and the SDK. The API must not only define the interfaces of any implementation in that language but also be able to function as a noop implementation of the tracer. The SDK is the default implementation of the API that must be optional.

apps/opentelemetry/test/opentelemetry_SUITE.erl

@@ -214,21 +214,28 @@ propagation(Config) ->
     ?assertMatch(#span_ctx{trace_flags=1}, ?current_span_ctx),
     ?assertMatch(#span_ctx{is_recording=true}, ?current_span_ctx),
 
-    otel_baggage:set("key-1", "value-1"),
-    otel_baggage:set("key-2", "value-2"),
+
+    otel_baggage:set("key-1", <<"value=1">>, []),
+    %% TODO: should the whole baggage entry be dropped if metadata is bad?
+    %% drop bad metadata (the `1').
+    otel_baggage:set(<<"key-2">>, <<"value-2">>, [<<"metadata">>, 1, {<<"md-k-1">>, <<"md-v-1">>}]),
+    %% drop baggage with bad value
+    otel_baggage:set(<<"key-3">>, value3),
+
     Headers = otel_propagator:text_map_inject([{<<"existing-header">>, <<"I exist">>}]),
 
     EncodedTraceId = io_lib:format("~32.16.0b", [TraceId]),
     EncodedSpanId = io_lib:format("~16.16.0b", [SpanId]),
 
-    ?assertListsEqual([{<<"baggage">>, "key-2=value-2,key-1=value-1"},
+    ?assertListsEqual([{<<"baggage">>, <<"key-2=value-2;metadata;md-k-1=md-v-1,key-1=value%3D1">>},
                        {<<"existing-header">>, <<"I exist">>} |
                        trace_context(Propagator, EncodedTraceId, EncodedSpanId)], Headers),
 
     ?end_span(SpanCtx),
 
-    ?assertEqual(#{"key-1" => "value-1",
-                   "key-2" => "value-2"}, otel_baggage:get_all()),
+    ?assertEqual(#{<<"key-1">> => {<<"value=1">>, []},
+                   <<"key-2">> => {<<"value-2">>, [<<"metadata">>, {<<"md-k-1">>, <<"md-v-1">>}]}},
+                 otel_baggage:get_all()),
 
     %% ?end_span doesn't remove the span from the context
     ?assertEqual(SpanCtx, ?current_span_ctx),
@@ -243,8 +250,9 @@ propagation(Config) ->
     BinaryHeaders = [{string:uppercase(Key), iolist_to_binary(Value)} || {Key, Value} <- Headers],
     otel_propagator:text_map_extract(BinaryHeaders),
 
-    ?assertEqual(#{"key-1" => "value-1",
-                   "key-2" => "value-2"}, otel_baggage:get_all()),
+    ?assertEqual(#{<<"key-1">> => {<<"value=1">>, []},
+                   <<"key-2">> => {<<"value-2">>, [<<"metadata">>, {<<"md-k-1">>, <<"md-v-1">>}]}},
+                 otel_baggage:get_all()),
 
     %% extracted remote spans are set to the active span
     %% but with `is_recording' false

apps/opentelemetry_api/lib/open_telemetry/baggage.ex

@@ -6,8 +6,12 @@ defmodule OpenTelemetry.Baggage do
   """
 
   defdelegate set(keyvalues), to: :otel_baggage
-  defdelegate set(key, values), to: :otel_baggage
+  defdelegate set(ctx_or_key, keyvalues), to: :otel_baggage
+  defdelegate set(ctx, key, value), to: :otel_baggage
+  defdelegate set(ctx, key, values, metadata), to: :otel_baggage
   defdelegate get_all(), to: :otel_baggage
+  defdelegate get_all(ctx), to: :otel_baggage
   defdelegate clear(), to: :otel_baggage
+  defdelegate clear(ctx), to: :otel_baggage
   defdelegate get_text_map_propagators(), to: :otel_baggage
 end