CLI will not pick up commands from implicitly enabled plugins

[lukebakken]

To reproduce:

• Download and un-archive the 3.8.2 generic-unix package
• sbin/rabbitmq-plugins enable rabbitmq_shovel_management
• sbin/rabbitmq-server
• sbin/rabbitmq-plugins list to verify plugins
• sbin/rabbitmqctl help - you will not see the shovel plugin items shovel_status, delete_shovel, etc

I see the same behavior using the zip package on Windows.

Running run-broker from master, I do see the plugin commands in the help output:

Management plugin:

   reset_stats_db                Resets statistics database. This will remove all metrics data!

Shovel plugin:

   delete_shovel                 Deletes a Shovel
   restart_shovel                Restarts a dynamic Shovel
   shovel_status                 Displays status of Shovel on a node

Use 'rabbitmqctl help <command>' to learn more about a specific command

Running them on a single node works. In a cluster, the full node name is required (including host name):

(22.2)lbakken@DSCH-WIN ~/development/rabbitmq/umbrella/deps/rabbitmq_server_release (master %=)
$ ./sbin/rabbitmqctl -n rabbit-1@DSCH-WIN shovel_status
Shovel status on node rabbit-1@DSCH-WIN

Otherwise:

(22.2)lbakken@DSCH-WIN ~/development/rabbitmq/umbrella/deps/rabbitmq_server_release (master %=)
$ ./sbin/rabbitmqctl -n rabbit-1 shovel_status

Command 'shovel_status' not found.
...
...
...

(Note: this may not be the correct repo for this issue)

[michaelklishin]

I can only reproduce in one known case: when a plugin is implicitly enabled (as a dependency). Those plugins won't participate in plugin discovery as for some code paths they are not really enabled.

[michaelklishin]

Some evidence:

rabbitmq-plugins list
Listing plugins with pattern ".*" ...
 Configured: E = explicitly enabled; e = implicitly enabled
 | Status: [failed to contact rabbit@warp10 - status not shown]
 |/
[  ] rabbitmq_amqp1_0                  3.8.3
[  ] rabbitmq_auth_backend_cache       3.8.3
[  ] rabbitmq_auth_backend_http        3.8.3
[  ] rabbitmq_auth_backend_ldap        3.8.3
[  ] rabbitmq_auth_backend_oauth2      3.8.3
[  ] rabbitmq_auth_mechanism_ssl       3.8.3
[  ] rabbitmq_consistent_hash_exchange 3.8.3
[  ] rabbitmq_event_exchange           3.8.3
[e ] rabbitmq_federation               3.8.3
[E ] rabbitmq_federation_management    3.8.3
[  ] rabbitmq_jms_topic_exchange       3.8.3
[e ] rabbitmq_management               3.8.3
[e ] rabbitmq_management_agent         3.8.3
[  ] rabbitmq_mqtt                     3.8.3
[  ] rabbitmq_peer_discovery_aws       3.8.3
[  ] rabbitmq_peer_discovery_common    3.8.3
[  ] rabbitmq_peer_discovery_consul    3.8.3
[  ] rabbitmq_peer_discovery_etcd      3.8.3
[  ] rabbitmq_peer_discovery_k8s       3.8.3
[  ] rabbitmq_prometheus               3.8.3
[  ] rabbitmq_random_exchange          3.8.3
[  ] rabbitmq_recent_history_exchange  3.8.3
[  ] rabbitmq_sharding                 3.8.3
[E ] rabbitmq_shovel                   3.8.3
[  ] rabbitmq_shovel_management        3.8.3
[  ] rabbitmq_stomp                    3.8.3
[  ] rabbitmq_top                      3.8.3
[  ] rabbitmq_tracing                  3.8.3
[  ] rabbitmq_trust_store              3.8.3
[e ] rabbitmq_web_dispatch             3.8.3
[  ] rabbitmq_web_mqtt                 3.8.3
[  ] rabbitmq_web_mqtt_examples        3.8.3
[  ] rabbitmq_web_stomp                3.8.3
[  ] rabbitmq_web_stomp_examples       3.8.3

and rabbitmqctl help includes

Shovel plugin:

   delete_shovel                 Deletes a Shovel
   restart_shovel                Restarts a dynamic Shovel
   shovel_status                 Displays status of Shovel on a node

Use 'rabbitmqctl help <command>' to learn more about a specific command

[michaelklishin]

One scenario in which I can reproduce this:

• Enable rabbitmq_shovel_management or rabbitmq_federation_management
• Enable rabbitmq_shovel which will be a no-op
• Observe no plugin commands discovered
• Disable rabbitmq_shovel_management
• Enable rabbitmq_shovel
• Observe plugin commands in help

CLI tools entirely depend on rabbit_plugins in discovering what plugins are enabled and should be placed on the code path.

I cannot reproduce any other way when the plugin that provides the command is enabled explicitly (not as a dependency of another plugin).

[michaelklishin]

RabbitMQ.CLI.Core.CodePath is where most of the relevant functions reside, e.g. https://github.com/rabbitmq/rabbitmq-cli/blob/master/lib/rabbitmq/cli/core/code_path.ex#L19.

[lukebakken]

OK, yes this is due to the plugin being enabled implicitly. It's pretty confusing behavior but I suspect most people enable both rabbitmq_shovel and rabbitmq_shovel_management at the same time. We can close this until someone else gets tripped up by it 😄