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/priority.lua

@@ -0,0 +1,81 @@
+--
+-- 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 ipairs = ipairs
+
+
+local _M = {}
+
+
+local function max_priority(a, b)
+    return a > b
+end
+
+
+function _M.new(up_nodes, upstream, picker_mod)
+    local priority_index = up_nodes._priority_index
+    core.table.sort(priority_index, max_priority)
+
+    local pickers = core.table.new(#priority_index, 0)
+    for i, priority in ipairs(priority_index) do
+        local picker, err = picker_mod.new(up_nodes[priority], upstream)
+        if not picker then
+            return nil, "failed to create picker with priority " .. priority .. ": " .. err
+        end
+        if not picker.before_retry_next_priority then
+            return nil, "picker should define 'before_retry_next_priority' to reset ctx"
+        end
+
+        pickers[i] = picker
+    end
+
+    return {
+        upstream = upstream,
+        get = function (ctx)
+            for i = ctx.priority_balancer_picker_idx or 1, #pickers do
+                local picker = pickers[i]
+                local server, err = picker.get(ctx)
+                if server then
+                    ctx.priority_balancer_picker_idx = i
+                    return server
+                end
+
+                core.log.notice("failed to get server from current priority ",
+                                priority_index[i],
+                                ", try next one, err: ", err)
+
+                picker.before_retry_next_priority(ctx)
+            end
+
+            return nil, "all servers tried"
+        end,
+        after_balance = function (ctx, before_retry)
+            local priority_balancer_picker = pickers[ctx.priority_balancer_picker_idx]
+            if not priority_balancer_picker or
+                not priority_balancer_picker.after_balance
+            then
+                return
+            end
+
+            priority_balancer_picker.after_balance(ctx, before_retry)
+        end
+    }
+end
+
+
+return _M