| -- Copyright (c) 2016 IBM. All rights reserved. |
| -- |
| -- Permission is hereby granted, free of charge, to any person obtaining a |
| -- copy of this software and associated documentation files (the "Software"), |
| -- to deal in the Software without restriction, including without limitation |
| -- the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| -- and/or sell copies of the Software, and to permit persons to whom the |
| -- Software is furnished to do so, subject to the following conditions: |
| -- |
| -- The above copyright notice and this permission notice shall be included in |
| -- all copies or substantial portions of the Software. |
| -- |
| -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| -- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| -- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| -- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| -- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| -- FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| -- DEALINGS IN THE SOFTWARE. |
| |
| --- @module rateLimit |
| |
| local utils = require "lib/utils" |
| local request = require "lib/request" |
| |
| local _M = {} |
| |
| --- Limit a resource/api/tenant, based on the passed in rateLimit object |
| -- @param red redis client instance |
| -- @param obj rateLimit object containing interval, rate, scope, subscription fields |
| -- @param apiKey optional api key to use if subscription is set to true |
| function limit(red, obj, apiKey) |
| local rate = obj.interval / obj.rate |
| local tenantId = ngx.var.tenant |
| local gatewayPath = ngx.var.gatewayPath |
| local k |
| -- Check scope |
| if obj.scope == "tenant" then |
| k = utils.concatStrings({"ratelimit:tenant:", tenantId}) |
| elseif obj.scope == "api" then |
| local apiId = ngx.var.apiId |
| k = utils.concatStrings({"ratelimit:tenant:", tenantId, ":api:", apiId}) |
| elseif obj.scope == "resource" then |
| k = utils.concatStrings({"ratelimit:tenant:", tenantId, ":resource:", gatewayPath}) |
| end |
| -- Check subscription |
| if obj.subscription ~= nil and obj.subscription == true and apiKey ~= nil then |
| k = utils.concatStrings({k, ":subscription:", apiKey}) |
| end |
| if red:get(k) == ngx.null then |
| red:set(k, "", "PX", math.floor(rate*1000)) |
| else |
| return request.err(429, 'Rate limit exceeded') |
| end |
| end |
| |
| _M.limit = limit |
| |
| return _M |