Otel declarative configuration

CHANGELOG.md

@@ -7,6 +7,25 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### SDK 
+
+#### Added
+
+- Support `OTEL_EXPERIMENTAL_CONFIG_FILE` environment variable to specify a json
+  file assumed to already be validated against the Otel file configuration
+  jsonschema.
+- Support the new file configuration schema as Erlang application environment
+  configuration in addition to as json.
+
+#### Changes
+
+- *Deprecated*: Resource attribute configuration: No longer use maps to
+  structure resource attribute keys with dots. Meaning use a key of
+  `service.name` instead of `#{service => #{name => ...}}` to represent
+  `service.name` attribute in the resource.
+- Options passed to the start of a tracer server and span processor have changed
+  to correspond to the file configuration schema.
+
 ## Experimental API 0.5.2 - 2024-11-22
 
 ### Added

apps/opentelemetry/src/opentelemetry_app.erl

@@ -24,8 +24,18 @@
 -include_lib("opentelemetry_api/include/opentelemetry.hrl").
 
 start(_StartType, _StartArgs) ->
-    Config = otel_configuration:merge_with_os(
-               application:get_all_env(opentelemetry)),
+    Env = application:get_all_env(opentelemetry),
+    Config = case os:getenv("OTEL_EXPERIMENTAL_CONFIG_FILE") of
+                 false ->
+                     case proplists:get_value(config_file, Env) of
+                         undefined ->
+                             otel_configuration:merge_with_os(Env);
+                         File ->
+                             otel_configuration:merge_with_env(otel_file_configuration:parse_file(File), Env)
+                     end;
+                 File ->
+                     otel_configuration:merge_with_env(otel_file_configuration:parse_file(File), Env)
+             end,
 
     %% set the global propagators for HTTP based on the application env
     %% these get set even if the SDK is disabled
@@ -34,7 +44,7 @@ start(_StartType, _StartArgs) ->
     SupResult = opentelemetry_sup:start_link(Config),
 
     case Config of
-        #{sdk_disabled := true} ->
+        #{disabled := true} ->
             %% skip the rest if the SDK is disabled
             SupResult;
         _ ->
@@ -57,8 +67,14 @@ stop(_State) ->
 
 %% internal functions
 
-setup_text_map_propagators(#{text_map_propagators := List}) ->
-    CompositePropagator = otel_propagator_text_map_composite:create(List),
+setup_text_map_propagators(Config) ->
+    Propagator = maps:get(propagator, Config, #{}),
+    PropagatorList = maps:get(composite_list, Propagator, []),
+    Propagators = maps:get(composite, Propagator, []),
+
+    Combined = append_if_not_found(otel_configuration:transform(propagators, PropagatorList), Propagators),
+
+    CompositePropagator = otel_propagator_text_map_composite:create(Combined),
     opentelemetry:set_text_map_propagator(CompositePropagator).
 
 create_loaded_application_tracers(#{create_application_tracers := true}) ->
@@ -68,3 +84,13 @@ create_loaded_application_tracers(#{create_application_tracers := true}) ->
     ok;
 create_loaded_application_tracers(_) ->
     ok.
+
+append_if_not_found([], Existing) ->
+    Existing;
+append_if_not_found([C | Rest], Existing) ->
+    case lists:member(C, Existing) of
+        true ->
+            append_if_not_found(Rest, Existing);
+        false ->
+            append_if_not_found(Rest, Existing ++ [C])
+    end.

apps/opentelemetry/src/opentelemetry_sup.erl

@@ -29,7 +29,7 @@
 start_link(Opts) ->
     supervisor:start_link({local, ?SERVER}, ?MODULE, [Opts]).
 
-init([#{sdk_disabled := true}]) ->
+init([#{disabled := true}]) ->
     {ok, {#{}, []}};
 init([Opts]) ->
     SupFlags = #{strategy => one_for_one,

apps/opentelemetry/src/otel_batch_processor.erl

@@ -147,8 +147,8 @@ init([Args=#{reg_name := RegName}]) ->
     process_flag(trap_exit, true),
 
     SizeLimit = maps:get(max_queue_size, Args, ?DEFAULT_MAX_QUEUE_SIZE),
-    ExportingTimeout = maps:get(exporting_timeout_ms, Args, ?DEFAULT_EXPORTER_TIMEOUT_MS),
-    ScheduledDelay = maps:get(scheduled_delay_ms, Args, ?DEFAULT_SCHEDULED_DELAY_MS),
+    ExportingTimeout = maps:get(export_timeout, Args, ?DEFAULT_EXPORTER_TIMEOUT_MS),
+    ScheduledDelay = maps:get(schedule_delay, Args, ?DEFAULT_SCHEDULED_DELAY_MS),
     CheckTableSize = maps:get(check_table_size_ms, Args, ?DEFAULT_CHECK_TABLE_SIZE_MS),
 
     %% TODO: this should be passed in from the tracer server