Deleting bindings is not working

[vdm24]

Describe the bug

Let's assume we have a server v4.2.1 with default configuration and activated rabbitmq_stream_management plugin.
If we create a new stream queue, an exchange, and bind them together, than we cannot delete the binding anymore.

Reproduction steps

1. Start the server with default configuration in a docker container with "rabbit4" name and ports mapping:

docker run -p 5672:5672 -p 15672:15672 -p 5552:5552 -d --name rabbit4 rabbitmq:4.2.1-management-alpine

2. Activate rabbitmq_stream_management and rabbitmq_stream plugins:

docker exec -it rabbit4 rabbitmq-plugins enable rabbitmq_stream_management

3. Import this config:

{
  "queues": [
    {
      "name": "cache-invalidate",
      "vhost": "/",
      "durable": true,
      "arguments": {
        "x-queue-type": "stream",
        "x-max-age": "3h",
        "x-stream-max-segment-size-bytes": 100000,
        "x-max-length-bytes": 1000000
      }
    }
  ],
  "exchanges": [
    {
      "name": "invalidate-cache-exchange",
      "vhost": "/",
      "type": "topic",
      "durable": true
    }
  ],
  "bindings": [
    {
      "source": "invalidate-cache-exchange",
      "vhost": "/",
      "destination": "cache-invalidate",
      "destination_type": "queue",
      "routing_key": "cache.invalidate"
    }
  ]
}

using any possible way, via the web interface or with this command:

cat /path/to/config.json | docker exec -i rabbit4 rabbitmqctl import_definitions /dev/stdin

4. Go to http://localhost:15672/#/queues/%2F/cache-invalidate
5. Login with guest/guest
6. Now try to delete the appended binding by pressing "Unbind" button. You will see this:

and the server log has this:

2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0> Unbinding error: {'EXIT',
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>     {{case_clause,
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>          {ok,{exchange,
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>                  {resource,<<"/">>,exchange,<<"invalidate-cache-exchange">>},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>                  topic,true,undefined,false,[],undefined,undefined,undefined,
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>                  {[],[]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>                  #{user => <<"rmq-internal">>}}}},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>      [{rabbit_db_exchange,maybe_auto_delete_in_khepri,2,
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>           [{file,"rabbit_db_exchange.erl"},{line,960}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {rabbit_db_binding,maybe_auto_delete_exchange_in_khepri,4,
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>           [{file,"rabbit_db_binding.erl"},{line,389}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {horus,exec,2,[{file,"src/horus.erl"},{line,1026}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {khepri_tx_adv,run,5,[{file,"src/khepri_tx_adv.erl"},{line,1013}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {khepri_machine,apply,3,[{file,"src/khepri_machine.erl"},{line,1535}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {khepri_machine,apply,3,[{file,"src/khepri_machine.erl"},{line,1665}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {ra_server,apply_with,2,[{file,"src/ra_server.erl"},{line,2830}]},
2025-12-12 18:57:29.990532+00:00 [warning] <0.1998.0>       {ra_log,fold,5,[{file,"src/ra_log.erl"},{line,471}]}]}}

Expected behavior

The binding should be deleted successfully, fithout any errors.

Additional context

No response

[lukebakken]

Thank you for the clear reproduction steps! I'm following them now.

UPDATE: yep, reproduced (https://github.com/lukebakken/rabbitmq-server-15128)

[lukebakken]

Interesting, auto_delete in the exchange record is undefined because of this code in rabbit_definitions:

            case rabbit_exchange:declare(Name,
                                         rabbit_exchange:check_type(maps:get(type, Exchange, undefined)),
                                         maps:get(durable,                         Exchange, undefined),
                                         maps:get(auto_delete,                     Exchange, undefined),
                                         Internal,
                                         args(maps:get(arguments, Exchange, undefined)),
                                         ActingUser) of

[michaelklishin]

Binding deletion used an incorrect pattern #15024, addressed in #15025.

[lukebakken]

Hold on there tiger, I don't think this is the same issue.

The provided definitions file does not set auto_delete for the exchange, thus undefined is used, which is probably not what we want. Notice that the code that declares queues via a definitions file does specify default values:

            AutoDelete = maps:get(auto_delete, Queue, false),
            DurableDeclare = maps:get(durable, Queue, true),
            ExclusiveDeclare = maps:get(exclusive, Queue, false),

[lukebakken]

Tested by starting a broker via make run-broker and @vdm24's reproduction steps: #15130

@vdm24 if this is blocking your work, just add durable and auto_delete to your definition file, and the exchange will be imported correctly.