debian-mirror-gitlab/lib/gitlab/application_rate_limiter.rb
2022-03-02 08:16:31 +05:30

209 lines
9 KiB
Ruby

# frozen_string_literal: true
module Gitlab
# This class implements a simple rate limiter that can be used to throttle
# certain actions. Unlike Rack Attack and Rack::Throttle, which operate at
# the middleware level, this can be used at the controller or API level.
# See CheckRateLimit concern for usage.
class ApplicationRateLimiter
InvalidKeyError = Class.new(StandardError)
def initialize(key, **options)
@key = key
@options = options
end
def throttled?
self.class.throttled?(key, **options)
end
def threshold_value
options[:threshold] || self.class.threshold(key)
end
def interval_value
self.class.interval(key)
end
class << self
# Application rate limits
#
# Threshold value can be either an Integer or a Proc
# in order to not evaluate it's value every time this method is called
# and only do that when it's needed.
def rate_limits
{
issues_create: { threshold: -> { application_settings.issues_create_limit }, interval: 1.minute },
notes_create: { threshold: -> { application_settings.notes_create_limit }, interval: 1.minute },
project_export: { threshold: -> { application_settings.project_export_limit }, interval: 1.minute },
project_download_export: { threshold: -> { application_settings.project_download_export_limit }, interval: 1.minute },
project_repositories_archive: { threshold: 5, interval: 1.minute },
project_generate_new_export: { threshold: -> { application_settings.project_export_limit }, interval: 1.minute },
project_import: { threshold: -> { application_settings.project_import_limit }, interval: 1.minute },
project_testing_hook: { threshold: 5, interval: 1.minute },
play_pipeline_schedule: { threshold: 1, interval: 1.minute },
raw_blob: { threshold: -> { application_settings.raw_blob_request_limit }, interval: 1.minute },
group_export: { threshold: -> { application_settings.group_export_limit }, interval: 1.minute },
group_download_export: { threshold: -> { application_settings.group_download_export_limit }, interval: 1.minute },
group_import: { threshold: -> { application_settings.group_import_limit }, interval: 1.minute },
group_testing_hook: { threshold: 5, interval: 1.minute },
profile_add_new_email: { threshold: 5, interval: 1.minute },
web_hook_calls: { interval: 1.minute },
users_get_by_id: { threshold: 10, interval: 1.minute },
username_exists: { threshold: 20, interval: 1.minute },
user_sign_up: { threshold: 20, interval: 1.minute },
profile_resend_email_confirmation: { threshold: 5, interval: 1.minute },
profile_update_username: { threshold: 10, interval: 1.minute },
update_environment_canary_ingress: { threshold: 1, interval: 1.minute },
auto_rollback_deployment: { threshold: 1, interval: 3.minutes },
user_email_lookup: { threshold: -> { application_settings.user_email_lookup_limit }, interval: 1.minute },
gitlab_shell_operation: { threshold: 600, interval: 1.minute }
}.freeze
end
# Increments the given key and returns true if the action should
# be throttled.
#
# @param key [Symbol] Key attribute registered in `.rate_limits`
# @param scope [Array<ActiveRecord>] Array of ActiveRecord models, Strings or Symbols to scope throttling to a specific request (e.g. per user per project)
# @param threshold [Integer] Optional threshold value to override default one registered in `.rate_limits`
# @param users_allowlist [Array<String>] Optional list of usernames to exclude from the limit. This param will only be functional if Scope includes a current user.
# @param peek [Boolean] Optional. When true the key will not be incremented but the current throttled state will be returned.
#
# @return [Boolean] Whether or not a request should be throttled
def throttled?(key, scope:, threshold: nil, users_allowlist: nil, peek: false)
raise InvalidKeyError unless rate_limits[key]
return false if scoped_user_in_allowlist?(scope, users_allowlist)
threshold_value = threshold || threshold(key)
return false if threshold_value == 0
interval_value = interval(key)
# `period_key` is based on the current time and interval so when time passes to the next interval
# the key changes and the rate limit count starts again from 0.
# Based on https://github.com/rack/rack-attack/blob/886ba3a18d13c6484cd511a4dc9b76c0d14e5e96/lib/rack/attack/cache.rb#L63-L68
period_key, time_elapsed_in_period = Time.now.to_i.divmod(interval_value)
cache_key = cache_key(key, scope, period_key)
value = if peek
read(cache_key)
else
increment(cache_key, interval_value, time_elapsed_in_period)
end
value > threshold_value
end
# Returns the current rate limited state without incrementing the count.
#
# @param key [Symbol] Key attribute registered in `.rate_limits`
# @param scope [Array<ActiveRecord>] Array of ActiveRecord models to scope throttling to a specific request (e.g. per user per project)
# @param threshold [Integer] Optional threshold value to override default one registered in `.rate_limits`
# @param users_allowlist [Array<String>] Optional list of usernames to exclude from the limit. This param will only be functional if Scope includes a current user.
#
# @return [Boolean] Whether or not a request is currently throttled
def peek(key, scope:, threshold: nil, users_allowlist: nil)
throttled?(key, peek: true, scope: scope, threshold: threshold, users_allowlist: users_allowlist)
end
# Logs request using provided logger
#
# @param request [Http::Request] - Web request to be logged
# @param type [Symbol] A symbol key that represents the request
# @param current_user [User] Current user of the request, it can be nil
# @param logger [Logger] Logger to log request to a specific log file. Defaults to Gitlab::AuthLogger
def log_request(request, type, current_user, logger = Gitlab::AuthLogger)
request_information = {
message: 'Application_Rate_Limiter_Request',
env: type,
remote_ip: request.ip,
request_method: request.request_method,
path: request.fullpath
}
if current_user
request_information.merge!({
user_id: current_user.id,
username: current_user.username
})
end
logger.error(request_information)
end
private
def threshold(key)
value = rate_limit_value_by_key(key, :threshold)
return value.call if value.is_a?(Proc)
value.to_i
end
def interval(key)
rate_limit_value_by_key(key, :interval).to_i
end
def rate_limit_value_by_key(key, setting)
action = rate_limits[key]
action[setting] if action
end
# Increments the rate limit count and returns the new count value.
def increment(cache_key, interval_value, time_elapsed_in_period)
# We add a 1 second buffer to avoid timing issues when we're at the end of a period
expiry = interval_value - time_elapsed_in_period + 1
::Gitlab::Redis::RateLimiting.with do |redis|
redis.pipelined do
redis.incr(cache_key)
redis.expire(cache_key, expiry)
end.first
end
end
# Returns the rate limit count.
# Will be 0 if there is no data in the cache.
def read(cache_key)
::Gitlab::Redis::RateLimiting.with do |redis|
redis.get(cache_key).to_i
end
end
def cache_key(key, scope, period_key)
composed_key = [key, scope].flatten.compact
serialized = composed_key.map do |obj|
if obj.is_a?(String) || obj.is_a?(Symbol)
"#{obj}"
else
"#{obj.class.model_name.to_s.underscore}:#{obj.id}"
end
end.join(":")
"application_rate_limiter:#{serialized}:#{period_key}"
end
def application_settings
Gitlab::CurrentSettings.current_application_settings
end
def scoped_user_in_allowlist?(scope, users_allowlist)
return unless users_allowlist.present?
scoped_user = [scope].flatten.find { |s| s.is_a?(User) }
return unless scoped_user
scoped_user.username.downcase.in?(users_allowlist)
end
end
private
attr_reader :key, :options
end
end