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/least_conn.lua

@@ -0,0 +1,113 @@
+--
+-- 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 core = require("apisix.core")
+local binaryHeap = require("binaryheap")
+local ipairs = ipairs
+local pairs = pairs
+
+
+local _M = {}
+
+
+local function least_score(a, b)
+    return a.score < b.score
+end
+
+
+function _M.new(up_nodes, upstream)
+    local servers_heap = binaryHeap.minUnique(least_score)
+    for server, weight in pairs(up_nodes) do
+        local score = 1 / weight
+        -- Note: the argument order of insert is different from others
+        servers_heap:insert({
+            server = server,
+            effect_weight = 1 / weight,
+            score = score,
+        }, server)
+    end
+
+    return {
+        upstream = upstream,
+        get = function (ctx)
+            local server, info, err
+            if ctx.balancer_tried_servers then
+                local tried_server_list = {}
+                while true do
+                    server, info = servers_heap:peek()
+                    -- we need to let the retry > #nodes so this branch can be hit and
+                    -- the request will retry next priority of nodes
+                    if server == nil then
+                        err = "all upstream servers tried"
+                        break
+                    end
+
+                    if not ctx.balancer_tried_servers[server] then
+                        break
+                    end
+
+                    servers_heap:pop()
+                    core.table.insert(tried_server_list, info)
+                end
+
+                for _, info in ipairs(tried_server_list) do
+                    servers_heap:insert(info, info.server)
+                end
+            else
+                server, info = servers_heap:peek()
+            end
+
+            if not server then
+                return nil, err
+            end
+
+            info.score = info.score + info.effect_weight
+            servers_heap:update(server, info)
+            return server
+        end,
+        after_balance = function (ctx, before_retry)
+            local server = ctx.balancer_server
+            local info = servers_heap:valueByPayload(server)
+            info.score = info.score - info.effect_weight
+            servers_heap:update(server, info)
+
+            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[server] = true
+        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
+        end,
+    }
+end
+
+
+return _M