keystone-manage hangs when the AMQP server is down

[Lance Bragstad]

Keystone supports notifications via oslo.messaging. Included with oslo.messaging notifications is the ability to emit messages using AMQP (e.g., rabbitmq).

Keystone uses notification extensively in its API to signal when resources are modified (creating, updating, or deleting users, projects, domains, role assignments, etc).

If keystone is configured to use AMQP for notifications but the AMQP server isn't reachable, keystone-manage will hang.

Steps to reproduce:

1. install a fresh devstack with keystone and rabbit as enabled services
2. configure keystone to emit messages using the messagingv2 driver and put a typo in the connection string

[oslo_messaging_notifications]
transport_url = rabbit://stackrabbit:stackqueue@10.10.3.122:5672/
driver = messagingv2

3. restart keystone
4. run keystone-manage bootstrap --bootstrap-password $password

You'd expect keystone-manage to handle connections with rabbit gracefully but it hangs.

https://pasted.tech/pastes/2a87e13e2e9e7323a93a14419ef6ebf55881621e.raw