Current Behavior

When stream_route references an upstream, it cannot configure key: mqtt_client_id for load balancing in the upstream.

Expected Behavior

No response

Error Logs

No response

Steps to Reproduce

curl --noproxy '*' http://apisix-admin:9180/apisix/admin/upstreams/mqtt -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
  "nodes": {
    "httpbin.org:80": 1
  },
  "type": "chash",
  "key": "mqtt_client_id"
}
'

{"error_msg":"invalid configuration: failed to match pattern \"^((uri|server_name|server_addr|request_uri|remote_port|remote_addr|query_string|host|hostname)|arg_[0-9a-zA-z_-]+)$\" with \"mqtt_client_id\""}

Environment

• APISIX version (run apisix version): 3.2.0
• Operating system (run uname -a):
• OpenResty / Nginx version (run openresty -V or nginx -V):
• etcd version, if relevant (run curl http://127.0.0.1:9090/v1/server_info):
• APISIX Dashboard version, if relevant:
• Plugin runner version, for issues related to plugin runners:
• LuaRocks version, for installation issues (run luarocks --version):