initialize_request = function()

in kong/kong/plugins/zipkin/handler.lua [120:193]

• 60 lines of code
• 10 McCabe index (conditional complexity)

  initialize_request = function(conf, ctx)
    local req = kong.request

    local req_headers = req.get_headers()

    local header_type, trace_id, span_id, parent_id, should_sample, baggage =
      propagation.parse(req_headers, conf.header_type)

    local method = req.get_method()

    if should_sample == nil then
      should_sample = math_random() < conf.sample_ratio
    end

    if trace_id == nil then
      trace_id = rand_bytes(conf.traceid_byte_count)
    end

    local span_name = method
    local path = req.get_path()
    if conf.http_span_name == "method_path" then
      span_name = method .. ' ' .. path
    end

    local request_span = new_span(
      "SERVER",
      span_name,
      ngx_req_start_time_mu(),
      should_sample,
      trace_id,
      span_id,
      parent_id,
      baggage)

    local http_version = req.get_http_version()
    local protocol = http_version and 'HTTP/'..http_version or nil

    request_span.ip = kong.client.get_forwarded_ip()
    request_span.port = kong.client.get_forwarded_port()

    request_span:set_tag("lc", "kong")
    request_span:set_tag("http.method", method)
    request_span:set_tag("http.host", req.get_host())
    request_span:set_tag("http.path", path)
    if protocol then
      request_span:set_tag("http.protocol", protocol)
    end

    local static_tags = conf.static_tags
    if type(static_tags) == "table" then
      for i = 1, #static_tags do
        local tag = static_tags[i]
        request_span:set_tag(tag.name, tag.value)
      end
    end

    local req_tags, err = request_tags.parse(req_headers[conf.tags_header])
    if err then
      
      kong.log.warn(err)
    end
    if req_tags then
      for tag_name, tag_value in pairs(req_tags) do
        request_span:set_tag(tag_name, tag_value)
      end
    end

    ctx.zipkin = {
      request_span = request_span,
      header_type = header_type,
      proxy_span = nil,
      header_filter_finished = false,
    }
  end