Unable to delete binding with undefined routing key

[tomhreb]

Hi,

• RabbitMQ version: 3.7.15
• Erlang version: 22.0
• RabbitMQ server and client application log files
  • no entry found in log file.
• A runnable code sample, terminal transcript or detailed set of
  instructions that can be used to reproduce the issue
• RabbitMQ plugin information via rabbitmq-plugins list
  • rabbitmq_management
  • rabbitmq_management_agent
  • rabbitmq_web_dispatch
• Client library version (for all libraries used)
  • powershell
• Operating system, version, and patch level
  • Windows Server 2019 Standard

When a binding is created through Management API with routing_key: null, it is not possible to delete such binding through DELETE api call: /api/bindings/vhost/e/exchange/q/queue/props.

API returns 404 Not Found

Invoke-RestMethod -Method Post -Uri https://rabbit01.hrebitom.poc:15671/api/definitions -Headers $headers -Body (  @{"exchanges" = @(@{"name" = "test"; "type" = "headers"; "vhost" = "/"; "durable" = $true; "auto_delete" = $false; "internal"= "false"; "arguments" = @{}}); "queues" = @(@{"name" = "test"; "vhost" = "/"; "durable" = $true; "auto_delete" = $false; "arguments" = @{}}); "bindings" = @( @{"source" = "test"; "destination" = "test"; "destination_type"= "queue"; "vhost" = "/"; "arguments" = @{} })} | ConvertTo-Json -Depth 10 )

Invoke-RestMethod -Method Get -Uri https://rabbit01.hrebitom.poc:15671/api/bindings/%2F/e/test/q/test -Headers $headers
# => 
# source           : test
# vhost            : /
# destination      : test
# destination_type : queue
# routing_key      : undefined
# arguments        :
# properties_key   : undefined

Invoke-RestMethod -Method Delete -Uri https://rabbit01.hrebitom.poc:15671/api/bindings/%2F/e/test/q/test/undefined -Headers $headers
# Invoke-RestMethod : {"error":"Object Not Found","reason":"Not Found"}

It's also not possible to delete the binding through Web UI.

Tom

[michaelklishin]

I have a patch but I'm not convinced we should adopt it. There is no such thing as a "null routing key" in AMQP 0-9-1 clients or management UI form. There is such as thing as a blank routing key.

So instead of correcting the binding lookup so that a 404 is not returned, routing key of null could be rejected or converted to a blank string. This is not great as this would be an implicit conversion but HTTP API allows one to do something that other protocols do not, and that's not by design.

[michaelklishin]

Some other parts of the HTTP API treat "null" values (which are just strings in some cases) as null atoms. So it makes more sense to do the same when looking up a binding to delete, even though that's also an implicit conversion.