A minimally functional OpenTelemetry setup to send traces to Honeycomb. This leaves a lot to be desired, but is a starting point.

Gemfile

# Observability
gem "opentelemetry-sdk"
gem "opentelemetry-exporter-otlp"
gem "opentelemetry-instrumentation-all"

telemetry.rb

OpenTelemetry::SDK.configure do |c|
  c.service_name = "PlaneExpress-Fullfillment"
  c.service_version = ENV.fetch("HEROKU_RELEASE_VERSION", "v0-dev")

  api_key = ENV.fetch("HONEYCOMB_API_KEY", nil)

  if api_key.present?
    oltp_exporter = OpenTelemetry::Exporter::OTLP::Exporter.new(
      endpoint: "https://api.honeycomb.io:443/v1/traces",
      headers: {
        "x-honeycomb-team" => api_key,
        "x-honeycomb-dataset" => "planetexpress - production"
      },
      compression: "gzip"
    )
    batch_processor = OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor.new(oltp_exporter)
    c.add_span_processor(batch_processor)
  end

  env = ENV.fetch("RACK_ENV")

  if env == "development"
    console_exporter = OpenTelemetry::SDK::Trace::Export::ConsoleSpanExporter.new
    c.add_span_processor(OpenTelemetry::SDK::Trace::Export::SimpleSpanProcessor.new(console_exporter))
  elsif env == "test"
    in_memory_exporter = OpenTelemetry::SDK::Trace::Export::InMemorySpanExporter.new(recording: false)
    c.add_span_processor(OpenTelemetry::SDK::Trace::Export::SimpleSpanProcessor.new(in_memory_exporter))
  end

  c.use_all # enables all instrumentation, watch out!
end