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/stream/plugins/mqtt-proxy.lua

@@ -0,0 +1,186 @@
+--
+-- 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 bit       = require("bit")
+local ngx       = ngx
+local str_byte  = string.byte
+local str_sub   = string.sub
+
+
+core.ctx.register_var("mqtt_client_id", function(ctx)
+    return ctx.mqtt_client_id
+end)
+
+
+local schema = {
+    type = "object",
+    properties = {
+        protocol_name = {type = "string"},
+        protocol_level = {type = "integer"}
+    },
+    required = {"protocol_name", "protocol_level"},
+}
+
+
+local plugin_name = "mqtt-proxy"
+
+
+local _M = {
+    version = 0.1,
+    priority = 1000,
+    name = plugin_name,
+    schema = schema,
+}
+
+
+function _M.check_schema(conf)
+    return core.schema.check(schema, conf)
+end
+
+
+local function decode_variable_byte_int(data, offset)
+    local multiplier = 1
+    local len = 0
+    local pos
+    for i = offset, offset + 3 do
+        pos = i
+        local byte = str_byte(data, i, i)
+        len = len + bit.band(byte, 127) * multiplier
+        multiplier = multiplier * 128
+        if bit.band(byte, 128) == 0 then
+            break
+        end
+    end
+
+    return len, pos
+end
+
+
+local function parse_msg_hdr(data)
+    local packet_type_flags_byte = str_byte(data, 1, 1)
+    if packet_type_flags_byte < 16 or packet_type_flags_byte > 32 then
+        return nil, nil,
+            "Received unexpected MQTT packet type+flags: " .. packet_type_flags_byte
+    end
+
+    local len, pos = decode_variable_byte_int(data, 2)
+    return len, pos
+end
+
+
+local function parse_mqtt(data, parsed_pos)
+    local res = {}
+
+    local protocol_len = str_byte(data, parsed_pos + 1, parsed_pos + 1) * 256
+                         + str_byte(data, parsed_pos + 2, parsed_pos + 2)
+    parsed_pos = parsed_pos + 2
+    res.protocol = str_sub(data, parsed_pos + 1, parsed_pos + protocol_len)
+    parsed_pos = parsed_pos + protocol_len
+
+    res.protocol_ver = str_byte(data, parsed_pos + 1, parsed_pos + 1)
+    parsed_pos = parsed_pos + 1
+
+    -- skip control flags & keepalive
+    parsed_pos = parsed_pos + 3
+
+    if res.protocol_ver == 5 then
+        -- skip properties
+        local property_len
+        property_len, parsed_pos = decode_variable_byte_int(data, parsed_pos + 1)
+        parsed_pos = parsed_pos + property_len
+    end
+
+    local client_id_len = str_byte(data, parsed_pos + 1, parsed_pos + 1) * 256
+                          + str_byte(data, parsed_pos + 2, parsed_pos + 2)
+    parsed_pos = parsed_pos + 2
+
+    if parsed_pos + client_id_len > #data then
+        res.expect_len = parsed_pos + client_id_len
+        return res
+    end
+
+    if client_id_len == 0 then
+        -- A Server MAY allow a Client to supply a ClientID that has a length of zero bytes
+        res.client_id = ""
+    else
+        res.client_id = str_sub(data, parsed_pos + 1, parsed_pos + client_id_len)
+    end
+
+    parsed_pos = parsed_pos + client_id_len
+
+    res.expect_len = parsed_pos
+    return res
+end
+
+
+function _M.preread(conf, ctx)
+    local sock = ngx.req.socket()
+    -- the header format of MQTT CONNECT can be found in
+    -- https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html#_Toc3901033
+    local data, err = sock:peek(5)
+    if not data then
+        core.log.error("failed to read the msg header: ", err)
+        return 503
+    end
+
+    local remain_len, pos, err = parse_msg_hdr(data)
+    if not remain_len then
+        core.log.error("failed to parse the msg header: ", err)
+        return 503
+    end
+
+    local data, err = sock:peek(pos + remain_len)
+    if not data then
+        core.log.error("failed to read the Connect Command: ", err)
+        return 503
+    end
+
+    local res = parse_mqtt(data, pos)
+    if res.expect_len > #data then
+        core.log.error("failed to parse mqtt request, expect len: ",
+                        res.expect_len, " but got ", #data)
+        return 503
+    end
+
+    if res.protocol and res.protocol ~= conf.protocol_name then
+        core.log.error("expect protocol name: ", conf.protocol_name,
+                       ", but got ", res.protocol)
+        return 503
+    end
+
+    if res.protocol_ver and res.protocol_ver ~= conf.protocol_level then
+        core.log.error("expect protocol level: ", conf.protocol_level,
+                       ", but got ", res.protocol_ver)
+        return 503
+    end
+
+    core.log.info("mqtt client id: ", res.client_id)
+
+    -- when client id is missing, fallback to balance by client IP
+    if res.client_id ~= "" then
+        ctx.mqtt_client_id = res.client_id
+    end
+    return
+end
+
+
+function _M.log(conf, ctx)
+    core.log.info("plugin log phase, conf: ", core.json.encode(conf))
+end
+
+
+return _M