Class: ZipkinTracer::RackHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/zipkin-tracer/rack/zipkin-tracer.rb

Overview

This middleware reads Zipkin headers from the request and sets/creates a Trace.id usable by the rest of the app It will also send the trace to the Zipkin service using one of the methods configured.

Constant Summary collapse

PATH_INFO =

the following constants are defined only from rack 1.6

Rack::PATH_INFO rescue 'PATH_INFO'.freeze
REQUEST_METHOD = 
Rack::REQUEST_METHOD rescue 'REQUEST_METHOD'.freeze

Instance Method Summary collapse

Constructor Details

#initialize(app, config = nil) ⇒ RackHandler

Returns a new instance of RackHandler.



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# File 'lib/zipkin-tracer/rack/zipkin-tracer.rb', line 14

def initialize(app, config = nil)
  @app = app
  @config = Config.new(app, config).freeze
  @tracer = TracerFactory.new.tracer(@config)
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/zipkin-tracer/rack/zipkin-tracer.rb', line 20

def call(env)
  zipkin_env = ZipkinEnv.new(env, @config)
  trace_id = zipkin_env.trace_id
  TraceContainer.with_trace_id(trace_id) do
    if !trace_id.sampled?
      @app.call(env)
    else
      @tracer.with_new_span(trace_id, span_name(env)) do |span|
        span.kind = Trace::Span::Kind::SERVER
        trace!(span, zipkin_env) { @app.call(env) }
      end
    end
  end
end