ruby配置opentelemetry的插件

配置OpenTelemetry::SDK时，可以指定user_all或use

OpenTelemetry::SDK.configure do |c|
  # ...

  # 使用所有
  c.use_all({
    'OpenTelemetry::Instrumentation::Rack' => {
      url_quantization: ->(path, env) { "HTTP #{env['REQUEST_METHOD']} #{path}" }
    }
  })

  # 使用某些
  c.use 'OpenTelemetry::Instrumentation::Rack', { allowed_request_headers: [] }
end

它们会设置usemode为`USEMODEALL或USEMODE_ONE`。不能同时两种模式。

# opentelemetry-sdk-1.0.3/lib/opentelemetry/sdk/configurator.rb
def use(instrumentation_name, config = nil)
  check_use_mode!(USE_MODE_ONE)
  @instrumentation_names << instrumentation_name
  @instrumentation_config_map[instrumentation_name] = config if config
end

def use_all(instrumentation_config_map = {})
  check_use_mode!(USE_MODE_ALL)
  @instrumentation_config_map = instrumentation_config_map
end

def check_use_mode!(mode)
  @use_mode = mode if @use_mode == USE_MODE_UNSPECIFIED
  raise 'Use either `use_all` or `use`, but not both' unless @use_mode == mode
end

安装各个插件时，会从@instrumentation_config_map取出改插件对应的配置

# opentelemetry-sdk-1.0.3/lib/opentelemetry/sdk/configurator.rb
def install_instrumentation
  case @use_mode
  when USE_MODE_ONE
    OpenTelemetry::Instrumentation.registry.install(@instrumentation_names, @instrumentation_config_map)
  when USE_MODE_ALL
    OpenTelemetry::Instrumentation.registry.install_all(@instrumentation_config_map)
  end
end