Remove the deprecated rpc_backend configuration option

[Ken Giusti]

rpc_backend has been deprecated in favor of 'transport_url' since newton.

http://git.openstack.org/cgit/openstack/oslo.messaging/tree/oslo_messaging/transport.py#n48

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/500252

[Steve Kowalik (stevenk)]

This is complex, oslo.messaging's ConfFixture class only exports rpc_backend, and not transport_url, so that needs to be fixed first.

http://codesearch.openstack.org/?q=transport_driver&i=nope&files=&repos= shows what is left that refers to it.

https://review.openstack.org/#/c/570082/ is my branch to start us down this path.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/570082
Committed: https://git.openstack.org/cgit/openstack/oslo.messaging/commit/?id=7e4ca449a0a73b2151ad10bf38f71b48215dfffc
Submitter: Zuul
Branch: master

commit 7e4ca449a0a73b2151ad10bf38f71b48215dfffc
Author: Steve Kowalik <email address hidden>
Date: Fri Jun 1 11:45:12 2018 +1000

    Add ConfFixture.transport_url

    As the first step towards removing rpc_backend, we need all of the test
    fixtures to stop setting/using it via ConfFixture.transport_driver. Add
    ConfFixture.transport_url, and move the tests over to setting it rather
    than transport_driver.

    Partial-Bug: #1712399
    Change-Id: I6e2ae2b511fdc52790d5755a9aecaf2f427ab706

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/580910

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/580910
Committed: https://git.openstack.org/cgit/openstack/oslo.messaging/commit/?id=d3f6ca0b47e2a5a3413b27617d9655f02b191c6a
Submitter: Zuul
Branch: master

commit d3f6ca0b47e2a5a3413b27617d9655f02b191c6a
Author: Steve Kowalik <email address hidden>
Date: Thu Sep 13 15:01:27 2018 -0600

    Remove rpc_backend and ConfFixture.transport_driver

    Now that most projects have transitioned from using
    ConfFixture.transport_driver, we can remove it and rpc_backend as a
    whole. rpc_backend was first deprecated in 5.10.0, released during
    Ocata.

    Closes-Bug: #1712399
    Change-Id: I193cc0e613459a6dbbfd54ed0901a54ded78d712

[OpenStack Infra (hudson-openstack)]

Change abandoned by Ken Giusti (<email address hidden>) on branch: master
Review: https://review.openstack.org/500252
Reason: removal complete in master branch:

https://review.openstack.org/#/c/580910/

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/oslo.messaging 9.0.0 release.