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/balancer/roundrobin.lua

@@ -0,0 +1,89 @@
+--
+-- 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 roundrobin  = require("resty.roundrobin")
+local core = require("apisix.core")
+local nkeys = core.table.nkeys
+local pairs = pairs
+
+
+local _M = {}
+
+
+function _M.new(up_nodes, upstream)
+    local safe_limit = 0
+    for _, weight in pairs(up_nodes) do
+        -- the weight can be zero
+        safe_limit = safe_limit + weight + 1
+    end
+
+    local picker = roundrobin:new(up_nodes)
+    local nodes_count = nkeys(up_nodes)
+    return {
+        upstream = upstream,
+        get = function (ctx)
+            if ctx.balancer_tried_servers and ctx.balancer_tried_servers_count == nodes_count then
+                return nil, "all upstream servers tried"
+            end
+
+            local server, err
+            for i = 1, safe_limit do
+                server, err = picker:find()
+                if not server then
+                    return nil, err
+                end
+                if ctx.balancer_tried_servers then
+                    if not ctx.balancer_tried_servers[server] then
+                        break
+                    end
+                else
+                    break
+                end
+            end
+
+            return server
+        end,
+        after_balance = function (ctx, before_retry)
+            if not before_retry then
+                if ctx.balancer_tried_servers then
+                    core.tablepool.release("balancer_tried_servers", ctx.balancer_tried_servers)
+                    ctx.balancer_tried_servers = nil
+                end
+
+                return nil
+            end
+
+            if not ctx.balancer_tried_servers then
+                ctx.balancer_tried_servers = core.tablepool.fetch("balancer_tried_servers", 0, 2)
+            end
+
+            ctx.balancer_tried_servers[ctx.balancer_server] = true
+            ctx.balancer_tried_servers_count = (ctx.balancer_tried_servers_count or 0) + 1
+        end,
+        before_retry_next_priority = function (ctx)
+            if ctx.balancer_tried_servers then
+                core.tablepool.release("balancer_tried_servers", ctx.balancer_tried_servers)
+                ctx.balancer_tried_servers = nil
+            end
+
+            ctx.balancer_tried_servers_count = 0
+        end,
+    }
+end
+
+
+return _M