Metrics SDK initialization error with 'add_metric_reader'

[GBoucher42]

Following along the Readme for the Metris SDK. There's an error when running OpenTelemetry.meter_provider.add_metric_reader

# Create an exporter. This example exports metrics to the console.
console_metric_exporter = OpenTelemetry::SDK::Metrics::Export::ConsoleMetricPullExporter.new

# Add the exporter to the meter provider as a new metric reader.
OpenTelemetry.meter_provider.add_metric_reader(console_metric_exporter)

# Create a meter to generate instruments.
meter = OpenTelemetry.meter_provider.meter("SAMPLE_METER_NAME")

The error is

 NoMethodError:
       undefined method `add_metric_reader' for an instance of OpenTelemetry::Internal::ProxyMeterProvider

When going through the code, in metrics_api/lib/opentelemetry/internal/proxy_meter_provider.rb we can see that there is indeed no method called add_metric_reader unlike what we see in metrics_sdk/lib/opentelemetry/sdk/metrics/meter_provider.rb.

The documentation should probably refer to OpenTelemetry::SDK::Metrics::MeterProvider instead of OpenTelemetry.meter_provider.

Share details about your runtime

RUBY_ENGINE: "ruby"
RUBY_VERSION: "3.3.5"

Share a simplified reproduction if possible
Exactly like the Metrics' SDK Readme

console_metric_exporter = OpenTelemetry::SDK::Metrics::Export::ConsoleMetricPullExporter.new

# Add the exporter to the meter provider as a new metric reader.
OpenTelemetry.meter_provider.add_metric_reader(console_metric_exporter)

# Create a meter to generate instruments.
meter = OpenTelemetry.meter_provider.meter("SAMPLE_METER_NAME")

[kaylareopelle]

Hi @GBoucher42, thanks for bringing this to our attention!

This is puzzling. The OpenTelemetry::Internal::ProxyMeterProvider inherits from OpenTelemetry::SDK::Metrics::MeterProvider, so add_metric_reader should be brought in by the parent class.

I'm not able to reproduce the error locally on the latest version of the opentelemetry-metrics-sdk and and opentelemetry-metrics-api gems when I run those lines as part of the examples/metrics_sdk/metrics_collect.rb script.

I have a few questions to help us troubleshoot:

• What versions of opentelemetry-related gems are you using?
• Are you running the code in a script or within a web framework?
• If you clone the repo on Ruby 3.3.5 and run the examples/metrics_sdk/metrics_collect.rb script, does the same error appear in your environment?