Updated rack_attack with few new limits and organization

• Updated:
- rack_attack with few new limits: 20x1d chat conversation creates, 60x10m searches, un auth api 150x5m
- organized all throttles in file, added comments

config/initializers/rack_attack.rb

@@ -40,15 +40,6 @@ class Rack::Attack
     end
   end
 
-  PROTECTED_PATHS = %w(
-    /auth/sign_in
-    /auth
-    /auth/password
-    /auth/confirmation
-  ).freeze
-
-  PROTECTED_PATHS_REGEX = Regexp.union(PROTECTED_PATHS.map { |path| /\A#{Regexp.escape(path)}/ })
-
   # Always allow requests from localhost
   # (blocklist & throttles are skipped)
   Rack::Attack.safelist('allow from localhost') do |req|
@@ -56,57 +47,85 @@ class Rack::Attack
     req.remote_ip == '127.0.0.1' || req.remote_ip == '::1'
   end
 
+  # Rate limit API requests by authenticated users
   throttle('throttle_authenticated_api', limit: 300, period: 5.minutes) do |req|
     req.authenticated_user_id if req.api_request?
   end
 
-  throttle('throttle_unauthenticated_api', limit: 300, period: 5.minutes) do |req|
+  # Rate limit API requests by UN-authenticated users
+  throttle('throttle_unauthenticated_api', limit: 150, period: 5.minutes) do |req|
     req.remote_ip if req.api_request? && req.unauthenticated?
   end
 
+  # Rate limit API requests for submitting a media attachment
   throttle('throttle_api_media', limit: 30, period: 30.minutes) do |req|
     req.authenticated_user_id if req.post? && req.path.start_with?('/api/v1/media')
   end
 
+  # Rate limit requests for using media_proxy route
   throttle('throttle_media_proxy', limit: 30, period: 30.minutes) do |req|
     req.remote_ip if req.path.start_with?('/media_proxy')
   end
 
+  # Rate limit sign up route
   throttle('throttle_api_sign_up', limit: 5, period: 30.minutes) do |req|
     req.remote_ip if req.post? && req.path == '/api/v1/accounts'
   end
 
+  # Rate limit API search route
+  throttle('throttle_api_search', limit: 60, period: 10.minutes) do |req|
+    req.remote_ip if req.post? && req.path == '/api/v2/search'
+  end
+
   # Throttle paging, as it is mainly used for public pages and AP collections
   throttle('throttle_authenticated_paging', limit: 300, period: 15.minutes) do |req|
     req.authenticated_user_id if req.paging_request?
   end
 
+  # Rate limit paging requests (e.g. scrolling down explore/group timelines)
   throttle('throttle_unauthenticated_paging', limit: 300, period: 15.minutes) do |req|
     req.remote_ip if req.paging_request? && req.unauthenticated?
   end
 
+  # Rate limit API route for deleting a status
   API_DELETE_REBLOG_REGEX = /\A\/api\/v1\/statuses\/[\d]+\/unreblog/.freeze
   API_DELETE_STATUS_REGEX = /\A\/api\/v1\/statuses\/[\d]+/.freeze
-  API_POST_CHAT_MESSAGE_REGEX = /\A\/api\/v1\/chat_messages/.freeze
-  API_POST_FOLLOW_REGEX = /\A\/api\/v1\/accounts\/[\d]+\/follow/.freeze
-  API_POST_GROUP_PASSWORD_CHECK_REGEX = /\A\/api\/v1\/groups\/[\d]+\/password/.freeze
-
   throttle('throttle_api_delete', limit: 30, period: 30.minutes) do |req|
     req.authenticated_user_id if (req.post? && req.path =~ API_DELETE_REBLOG_REGEX) || (req.delete? && req.path =~ API_DELETE_STATUS_REGEX)
   end
 
+  # Rate limit API route creating a conversation
+  API_POST_CHAT_CONVERSATION_REGEX = /\A\/api\/v1\/chat_conversation/.freeze
+  throttle('throttle_api_chat_conversation', limit: 20, period: 1.day) do |req|
+    req.authenticated_user_id if req.post? && req.path =~ API_POST_CHAT_CONVERSATION_REGEX
+  end
+
+  # Rate limit API route sending a chat message
+  API_POST_CHAT_MESSAGE_REGEX = /\A\/api\/v1\/chat_messages/.freeze
   throttle('throttle_api_chat_message', limit: 1000, period: 1.day) do |req|
     req.authenticated_user_id if req.post? && req.path =~ API_POST_CHAT_MESSAGE_REGEX
   end
 
+  # Rate limit API route for following someone
+  API_POST_FOLLOW_REGEX = /\A\/api\/v1\/accounts\/[\d]+\/follow/.freeze
   throttle('throttle_api_follow', limit: 200, period: 1.day) do |req|
     req.authenticated_user_id if req.post? && req.path =~ API_POST_FOLLOW_REGEX
   end
 
+  # Rate limit API route for checking if a password to a group is correct
+  API_POST_GROUP_PASSWORD_CHECK_REGEX = /\A\/api\/v1\/groups\/[\d]+\/password/.freeze
   throttle('throttle_group_password_check', limit: 5, period: 1.minute) do |req|
     req.authenticated_user_id if req.post? && req.path =~ API_POST_GROUP_PASSWORD_CHECK_REGEX
   end
 
+  PROTECTED_PATHS = %w(
+    /auth/sign_in
+    /auth
+    /auth/password
+    /auth/confirmation
+  ).freeze
+  # Rate limit protected paths (auth for sign in, password, email confirmation)
+  PROTECTED_PATHS_REGEX = Regexp.union(PROTECTED_PATHS.map { |path| /\A#{Regexp.escape(path)}/ })
   throttle('protected_paths', limit: 10, period: 5.minutes) do |req|
     req.remote_ip if req.post? && req.path =~ PROTECTED_PATHS_REGEX
   end