feat(apisix): add Cloudron package

- Implements Apache APISIX packaging for Cloudron platform.
- Includes Dockerfile, CloudronManifest.json, and start.sh.
- Configured to use Cloudron's etcd addon.

🤖 Generated with Gemini CLI
Co-Authored-By: Gemini <noreply@google.com>

CloudronPackages/APISIX/apisix-source/apisix/plugins/limit-req/util.lua

@@ -0,0 +1,78 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one or more
+-- contributor license agreements.  See the NOTICE file distributed with
+-- this work for additional information regarding copyright ownership.
+-- The ASF licenses this file to You under the Apache License, Version 2.0
+-- (the "License"); you may not use this file except in compliance with
+-- the License.  You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+local math              = require "math"
+local abs               = math.abs
+local max               = math.max
+local ngx_now           = ngx.now
+local ngx_null          = ngx.null
+local tonumber          = tonumber
+
+
+local _M = {version = 0.1}
+
+
+-- the "commit" argument controls whether should we record the event in shm.
+function _M.incoming(self, red, key, commit)
+    local rate = self.rate
+    local now = ngx_now() * 1000
+
+    key = "limit_req" .. ":" .. key
+    local excess_key = key .. "excess"
+    local last_key = key .. "last"
+
+    local excess, err = red:get(excess_key)
+    if err then
+        return nil, err
+    end
+    local last, err = red:get(last_key)
+    if err then
+        return nil, err
+    end
+
+    if excess ~= ngx_null and last ~= ngx_null then
+        excess = tonumber(excess)
+        last = tonumber(last)
+        local elapsed = now - last
+        excess = max(excess - rate * abs(elapsed) / 1000 + 1000, 0)
+
+        if excess > self.burst then
+            return nil, "rejected"
+        end
+    else
+        excess = 0
+    end
+
+    if commit then
+        local ok
+        local err
+        ok, err = red:set(excess_key, excess)
+        if not ok then
+            return nil, err
+        end
+
+        ok, err = red:set(last_key, now)
+        if not ok then
+            return nil, err
+        end
+    end
+
+    -- return the delay in seconds, as well as excess
+    return excess / rate, excess / 1000
+end
+
+
+return _M