gitlab-org--gitlab-foss/lib/gitlab/metrics/rack_middleware.rb
2016-06-17 18:14:25 +02:00

74 lines
1.9 KiB
Ruby

module Gitlab
module Metrics
# Rack middleware for tracking Rails and Grape requests.
class RackMiddleware
CONTROLLER_KEY = 'action_controller.instance'
ENDPOINT_KEY = 'api.endpoint'
def initialize(app)
@app = app
end
# env - A Hash containing Rack environment details.
def call(env)
trans = transaction_from_env(env)
retval = nil
begin
retval = trans.run { @app.call(env) }
# Even in the event of an error we want to submit any metrics we
# might've gathered up to this point.
ensure
if env[CONTROLLER_KEY]
tag_controller(trans, env)
elsif env[ENDPOINT_KEY]
tag_endpoint(trans, env)
end
trans.finish
end
retval
end
def transaction_from_env(env)
trans = Transaction.new
trans.set(:request_uri, filtered_path(env))
trans.set(:request_method, env['REQUEST_METHOD'])
trans
end
def tag_controller(trans, env)
controller = env[CONTROLLER_KEY]
trans.action = "#{controller.class.name}##{controller.action_name}"
end
def tag_endpoint(trans, env)
endpoint = env[ENDPOINT_KEY]
path = endpoint_paths_cache[endpoint.route.route_method][endpoint.route.route_path]
trans.action = "Grape##{endpoint.route.route_method} #{path}"
end
private
def filtered_path(env)
ActionDispatch::Request.new(env).filtered_path.presence || env['REQUEST_URI']
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