Class: Datadog::Tracing::Contrib::Excon::Middleware

Inherits:
Excon::Middleware::Base
  • Object
show all
Includes:
HttpAnnotationHelper
Defined in:
lib/datadog/tracing/contrib/excon/middleware.rb

Overview

Middleware implements an excon-middleware for ddtrace instrumentation

Constant Summary collapse

DEFAULT_ERROR_HANDLER = 
lambda do |response|
  Tracing::Metadata::Ext::HTTP::ERROR_RANGE.cover?(response[:status])
end

Class Method Summary collapse

Instance Method Summary collapse

Methods included from HttpAnnotationHelper

#service_name

Constructor Details

#initialize(stack, options = {}) ⇒ Middleware

Returns a new instance of Middleware.



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# File 'lib/datadog/tracing/contrib/excon/middleware.rb', line 22

def initialize(stack, options = {})
  super(stack)
  @default_options = datadog_configuration.options_hash.merge(options)
end

Class Method Details

.around_default_stack ⇒ Object

Returns a copy of the default stack with the trace middleware injected



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# File 'lib/datadog/tracing/contrib/excon/middleware.rb', line 82

def self.around_default_stack
  ::Excon.defaults[:middlewares].dup.tap do |default_stack|
    # If the default stack contains a version of the trace middleware already...
    existing_trace_middleware = default_stack.find { |m| m <= Middleware }
    default_stack.delete(existing_trace_middleware) if existing_trace_middleware

    # Inject after the ResponseParser middleware
    response_middleware_index = default_stack.index(::Excon::Middleware::ResponseParser).to_i
    default_stack.insert(response_middleware_index + 1, self)
  end
end

.with(options = {}) ⇒ Object

Returns a child class of this trace middleware With options given as defaults.



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# File 'lib/datadog/tracing/contrib/excon/middleware.rb', line 59

def self.with(options = {})
  Class.new(self) do
    @options = options

    # rubocop:disable Style/TrivialAccessors
    def self.options
      @options
    end
    # rubocop:enable Style/TrivialAccessors

    # default_options in this case contains our specific middleware options
    # so we want it to take precedence in build_request_options
    def build_request_options!(datum)
      datadog_configuration(datum[:host]).options_hash.merge(@default_options)
    end

    def initialize(stack)
      super(stack, self.class.options)
    end
  end
end

Instance Method Details

#error_call(datum) ⇒ Object 



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# File 'lib/datadog/tracing/contrib/excon/middleware.rb', line 52

def error_call(datum)
  handle_response(datum)
  @stack.error_call(datum)
end

#request_call(datum) ⇒ Object 



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# File 'lib/datadog/tracing/contrib/excon/middleware.rb', line 27

def request_call(datum)
  begin
    unless datum.key?(:datadog_span)
      @options = build_request_options!(datum)
      span = Tracing.trace(Ext::SPAN_REQUEST)
      trace = Tracing.active_trace
      datum[:datadog_span] = span
      annotate!(span, datum)
      propagate!(trace, span, datum) if distributed_tracing?

      span
    end
  rescue StandardError => e
    Datadog.logger.debug(e.message)
  end

  @stack.request_call(datum)
end

#response_call(datum) ⇒ Object 



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# File 'lib/datadog/tracing/contrib/excon/middleware.rb', line 46

def response_call(datum)
  @stack.response_call(datum).tap do |d|
    handle_response(d)
  end
end