gitlab-org--gitlab-foss/lib/gitlab/metrics/web_transaction.rb
Yorick Peterse d73e68deb5
Limit the action suffixes in transaction metrics
There seem to be a lot of cases where the suffix of an action (e.g.
".html") is set to bogus data, such as "*/*" or entire URLs. This can
increase cardinality of our metrics, and isn't very useful for
monitoring and filtering. To work around this, we enforce a whitelist
containing a few suffixes we actually care about. Suffixes not supported
will be grouped under the action without a suffix. This means that a
request to "FooController#bar.jpeg" will be assigned to
"FooController#bar".
2018-06-20 14:35:04 +02:00

79 lines
2.5 KiB
Ruby

module Gitlab
module Metrics
class WebTransaction < Transaction
CONTROLLER_KEY = 'action_controller.instance'.freeze
ENDPOINT_KEY = 'api.endpoint'.freeze
ALLOWED_SUFFIXES = Set.new(%w[json js atom rss xml zip])
def initialize(env)
super()
@env = env
end
def labels
return @labels if @labels
# memoize transaction labels only source env variables were present
@labels = if @env[CONTROLLER_KEY]
labels_from_controller || {}
elsif @env[ENDPOINT_KEY]
labels_from_endpoint || {}
end
@labels || {}
end
private
def labels_from_controller
controller = @env[CONTROLLER_KEY]
action = "#{controller.action_name}"
# Devise exposes a method called "request_format" that does the below.
# However, this method is not available to all controllers (e.g. certain
# Doorkeeper controllers). As such we use the underlying code directly.
suffix = controller.request.format.try(:ref).to_s
# Sometimes the request format is set to silly data such as
# "application/xrds+xml" or actual URLs. To prevent such values from
# increasing the cardinality of our metrics, we limit the number of
# possible suffixes.
if suffix && ALLOWED_SUFFIXES.include?(suffix)
action += ".#{suffix}"
end
{ controller: controller.class.name, action: action }
end
def labels_from_endpoint
endpoint = @env[ENDPOINT_KEY]
begin
route = endpoint.route
rescue
# endpoint.route is calling env[Grape::Env::GRAPE_ROUTING_ARGS][:route_info]
# but env[Grape::Env::GRAPE_ROUTING_ARGS] is nil in the case of a 405 response
# so we're rescuing exceptions and bailing out
end
if route
path = endpoint_paths_cache[route.request_method][route.path]
{ controller: 'Grape', action: "#{route.request_method} #{path}" }
end
end
def endpoint_paths_cache
@endpoint_paths_cache ||= Hash.new do |hash, http_method|
hash[http_method] = Hash.new do |inner_hash, raw_path|
inner_hash[raw_path] = endpoint_instrumentable_path(raw_path)
end
end
end
def endpoint_instrumentable_path(raw_path)
raw_path.sub('(.:format)', '').sub('/:version', '')
end
end
end
end