diff options
Diffstat (limited to 'lib/gitlab/rack_attack.rb')
| -rw-r--r-- | lib/gitlab/rack_attack.rb | 60 |
1 files changed, 58 insertions, 2 deletions
diff --git a/lib/gitlab/rack_attack.rb b/lib/gitlab/rack_attack.rb index 7c336153e32..2a94fb91880 100644 --- a/lib/gitlab/rack_attack.rb +++ b/lib/gitlab/rack_attack.rb @@ -10,14 +10,70 @@ module Gitlab def self.configure(rack_attack) # This adds some methods used by our throttles to the `Rack::Request` rack_attack::Request.include(Gitlab::RackAttack::Request) - # Send the Retry-After header so clients (e.g. python-gitlab) can make good choices about delays - Rack::Attack.throttled_response_retry_after_header = true + + # This is Rack::Attack::DEFAULT_THROTTLED_RESPONSE, modified to allow a custom response + Rack::Attack.throttled_response = lambda do |env| + throttled_headers = Gitlab::RackAttack.throttled_response_headers( + env['rack.attack.matched'], env['rack.attack.match_data'] + ) + [429, { 'Content-Type' => 'text/plain' }.merge(throttled_headers), [Gitlab::Throttle.rate_limiting_response_text]] + end + # Configure the throttles configure_throttles(rack_attack) configure_user_allowlist end + # Rate Limit HTTP headers are not standardized anywhere. This is the latest + # draft submitted to IETF: + # https://github.com/ietf-wg-httpapi/ratelimit-headers/blob/main/draft-ietf-httpapi-ratelimit-headers.md + # + # This method implement the most viable parts of the headers. Those headers + # will be sent back to the client when it gets throttled. + # + # - RateLimit-Limit: indicates the request quota associated to the client + # in 60 seconds. The time window for the quota here is supposed to be + # mirrored to throttle_*_period_in_seconds application settings. However, + # our HAProxy as well as some ecosystem libraries are using a fixed + # 60-second window. Therefore, the returned limit is approximately rounded + # up to fit into that window. + # + # - RateLimit-Observed: indicates the current request amount associated to + # the client within the time window. + # + # - RateLimit-Remaining: indicates the remaining quota within the time + # window. It is the result of RateLimit-Limit - RateLimit-Remaining + # + # - Retry-After: the remaining duration in seconds until the quota is + # reset. This is a standardized HTTP header: + # https://tools.ietf.org/html/rfc7231#page-69 + # + # - RateLimit-Reset: the point of time that the request quota is reset, in Unix time + # + # - RateLimit-ResetTime: the point of time that the request quota is reset, in HTTP date format + def self.throttled_response_headers(matched, match_data) + # Match data example: + # {:discriminator=>"127.0.0.1", :count=>12, :period=>60 seconds, :limit=>1, :epoch_time=>1609833930} + # Source: https://github.com/rack/rack-attack/blob/v6.3.0/lib/rack/attack/throttle.rb#L33 + period = match_data[:period] + limit = match_data[:limit] + rounded_limit = (limit.to_f * 1.minute / match_data[:period]).ceil + observed = match_data[:count] + now = match_data[:epoch_time] + retry_after = period - (now % period) + reset_time = Time.at(now + retry_after) # rubocop:disable Rails/TimeZone + { + 'RateLimit-Name' => matched.to_s, + 'RateLimit-Limit' => rounded_limit.to_s, + 'RateLimit-Observed' => observed.to_s, + 'RateLimit-Remaining' => (limit > observed ? limit - observed : 0).to_s, + 'RateLimit-Reset' => reset_time.to_i.to_s, + 'RateLimit-ResetTime' => reset_time.httpdate, + 'Retry-After' => retry_after.to_s + } + end + def self.configure_user_allowlist @user_allowlist = nil user_allowlist |