trace_config.rb in opentelemetry-sdk-0.12.0

- old
+ new

@@ -8,24 +8,10 @@
   module SDK
     module Trace
       module Config
         # Class that holds global trace parameters.
         class TraceConfig
-          DEFAULT_SAMPLER = Samplers.parent_based(root: Samplers::ALWAYS_ON)
-          DEFAULT_MAX_ATTRIBUTES_COUNT = 32
-          DEFAULT_MAX_EVENTS_COUNT = 128
-          DEFAULT_MAX_LINKS_COUNT = 32
-          DEFAULT_MAX_ATTRIBUTES_PER_EVENT = 32
-          DEFAULT_MAX_ATTRIBUTES_PER_LINK = 32
-
-          private_constant(:DEFAULT_SAMPLER,
-                           :DEFAULT_MAX_ATTRIBUTES_COUNT,
-                           :DEFAULT_MAX_EVENTS_COUNT,
-                           :DEFAULT_MAX_LINKS_COUNT,
-                           :DEFAULT_MAX_ATTRIBUTES_PER_EVENT,
-                           :DEFAULT_MAX_ATTRIBUTES_PER_LINK)
-
           # The global default sampler (see {Samplers}).
           attr_reader :sampler
 
           # The global default max number of attributes per {Span}.
           attr_reader :max_attributes_count
@@ -44,16 +30,16 @@
 
           # Returns a {TraceConfig} with the desired values.
           #
           # @return [TraceConfig] with the desired values.
           # @raise [ArgumentError] if any of the max numbers are not positive.
-          def initialize(sampler: DEFAULT_SAMPLER,
-                         max_attributes_count: DEFAULT_MAX_ATTRIBUTES_COUNT,
-                         max_events_count: DEFAULT_MAX_EVENTS_COUNT,
-                         max_links_count: DEFAULT_MAX_LINKS_COUNT,
-                         max_attributes_per_event: DEFAULT_MAX_ATTRIBUTES_PER_EVENT,
-                         max_attributes_per_link: DEFAULT_MAX_ATTRIBUTES_PER_LINK)
+          def initialize(sampler: sampler_from_environment(Samplers.parent_based(root: Samplers::ALWAYS_ON)),
+                         max_attributes_count: Integer(ENV.fetch('OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT', 1000)),
+                         max_events_count: Integer(ENV.fetch('OTEL_SPAN_EVENT_COUNT_LIMIT', 1000)),
+                         max_links_count: Integer(ENV.fetch('OTEL_SPAN_LINK_COUNT_LIMIT', 1000)),
+                         max_attributes_per_event: max_attributes_count,
+                         max_attributes_per_link: max_attributes_count)
             raise ArgumentError, 'max_attributes_count must be positive' unless max_attributes_count.positive?
             raise ArgumentError, 'max_events_count must be positive' unless max_events_count.positive?
             raise ArgumentError, 'max_links_count must be positive' unless max_links_count.positive?
             raise ArgumentError, 'max_attributes_per_event must be positive' unless max_attributes_per_event.positive?
             raise ArgumentError, 'max_attributes_per_link must be positive' unless max_attributes_per_link.positive?
@@ -65,9 +51,25 @@
             @max_attributes_per_event = max_attributes_per_event
             @max_attributes_per_link = max_attributes_per_link
           end
 
           # TODO: from_proto
+          private
+
+          def sampler_from_environment(default_sampler) # rubocop:disable Metrics/CyclomaticComplexity
+            case ENV['OTEL_TRACE_SAMPLER']
+            when 'always_on' then Samplers::ALWAYS_ON
+            when 'always_off' then Samplers::ALWAYS_OFF
+            when 'traceidratio' then Samplers.trace_id_ratio_based(Float(ENV['OTEL_TRACE_SAMPLER_ARG']))
+            when 'parentbased_always_on' then Samplers.parent_based(root: Samplers::ALWAYS_ON)
+            when 'parentbased_always_off' then Samplers.parent_based(root: Samplers::ALWAYS_OFF)
+            when 'parentbased_traceidratio' then Samplers.parent_based(root: Samplers.trace_id_ratio_based(Float(ENV['OTEL_TRACE_SAMPLER_ARG'])))
+            else default_sampler
+            end
+          rescue StandardError => e
+            OpenTelemetry.handle_error(exception: e, message: "installing default sampler #{default_sampler.description}")
+            default_sampler
+          end
 
           # The default {TraceConfig}.
           DEFAULT = new
         end
       end