Module: Net::Http::Instrumentation

Defined in:
lib/net/http/instrumentation.rb,
lib/net/http/instrumentation/version.rb

Constant Summary collapse

VERSION = 
"0.1.2"

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.ignore_request ⇒ Object

Returns the value of attribute ignore_request.



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# File 'lib/net/http/instrumentation.rb', line 10

def ignore_request
  @ignore_request
end

.tracer ⇒ Object

Returns the value of attribute tracer.



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# File 'lib/net/http/instrumentation.rb', line 10

def tracer
  @tracer
end

Class Method Details

.instrument(tracer: OpenTracing.global_tracer, ignore_request: nil) ⇒ Object 



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# File 'lib/net/http/instrumentation.rb', line 12

def instrument(tracer: OpenTracing.global_tracer, ignore_request: nil)
  @ignore_request = ignore_request
  @tracer = tracer

  patch_request if !@instrumented
  @instrumented = true
end

.patch_request ⇒ Object 



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# File 'lib/net/http/instrumentation.rb', line 32

def patch_request

  ::Net::HTTP.module_eval do
    alias_method :request_original, :request

    def request(req, body = nil, &block)
      res = ''

      if ::Net::Http::Instrumentation.ignore_request.respond_to?(:call) &&
         ::Net::Http::Instrumentation.ignore_request.call

        res = request_original(req, body, &block)
      else
        tags = {
          "component" => "Net::HTTP",
          "span.kind" => "client",
          "http.method" => req.method,
          "http.url" => req.path,
          "peer.host" => @address,
          "peer.port" => @port,
        }
        ::Net::Http::Instrumentation.tracer.start_active_span("net_http.request", tags: tags) do |scope|
          # inject the trace so it's available to the remote service
          OpenTracing.inject(scope.span.context, OpenTracing::FORMAT_RACK, req)

          # call the original request method
          res = request_original(req, body, &block)

          # set response code and error if applicable
          scope.span.set_tag("http.status_code", res.code)
          scope.span.set_tag("error", true) if res.is_a?(::Net::HTTPClientError)
        end
      end

      res
    end
  end
end

.remove ⇒ Object 



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# File 'lib/net/http/instrumentation.rb', line 20

def remove
  return if !@instrumented

  ::Net::HTTP.module_eval do
    remove_method :request
    alias_method :request, :request_original
    remove_method :request_original
  end

  @instrumented = false
end