example.erl

start(_StartType, _StartArgs) ->
    application:load(opentelemetry),

    application:set_env(opentelemetry, sampler, {always_on, #{}}),
    application:set_env(opentelemetry, processors, [{otel_batch_processor, #{exporter => {otel_exporter_stdout, []},
                                                                            exporting_timeout_ms => 100,
                                                                            scheduled_delay_ms => timer:seconds(5)}}]),
    {ok, _} = application:ensure_all_started(opentelemetry),
    {ok, _} = application:ensure_all_started(opentelemetry_api),

    otel_batch_processor:set_exporter(otel_exporter_stdout, []),
    true = opentelemetry:register_application_tracer(otel_example), 


    % otel_batch_processor:set_exporter(opentelemetry_exporter, #{protocol => http_protobuf,
    %                                                          endpoints => [
    %                                                          {http, "localhost", 9090, []}],
    %                                                          scheduled_delay_ms => 10000}),
    otel_example_sup:start_link().