https://github.com/openshift/openshift-ansible/pull/12095

Test on the following playbooks using openshift-ansible-3.11.187-1.git.0.154c878.el7.noarch.rpm and ansible-2.9.5-1.el7ae.  

* Installation
- playbooks/prerequisites.yml
- playbooks/deploy_cluster.yml

* Redeploy certificate
- playbooks/redeploy-certificates.yml

* Certificate expiry
- playbooks/openshift-checks/certificate_expiry/easy-mode.yaml

* Upgrade
- playbooks/byo/openshift-cluster/upgrades/v3_11/upgrade.yml

* Node scale-up
- playbooks/openshift-node/scaleup.yml

No issue found.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:0793

Please advise of the accompanying documentation to support this.

*** Bug 1832693 has been marked as a duplicate of this bug. ***

Testing this with Ansible-2.9 for OpenShift 3.11 on OpenStack 13, which requires openstacksdk. Initially I was just testing node scale-up which needs the openstack libraries to create the extra VM (which is also needed for a fresh install).

I get the following error (excerpt):

PLAY [Create the OpenStack resources for cluster installation or scaleup] ****************************************************************

TASK [openshift_openstack : Get subnet facts when using a custom subnet] *********************************************************[27/672]
task path: /usr/share/ansible/openshift-ansible/roles/openshift_openstack/tasks/provision.yml:2
Wednesday 13 May 2020  17:39:12 -0400 (0:00:00.080)       0:00:16.175 *********
Using module file /usr/lib/python2.7/site-packages/ansible/modules/cloud/openstack/_os_subnets_facts.py

fatal: [localhost]: FAILED! => {
    "changed": false,
    "invocation": {
        "module_args": {
            "api_timeout": null,
            "auth": null,
            "auth_type": null,
            "availability_zone": null,
            "ca_cert": null,
            "client_cert": null,
            "client_key": null,
            "cloud": null,
            "filters": null,
            "interface": "public",
            "name": "openshift-dev-subnet",
            "region_name": null,
            "timeout": 180,
            "validate_certs": null,
            "wait": true
        }
    },
    "msg": "To utilize this module, the installed version of the openstacksdk library MUST be >=0.12."
}

$ rpm -qa |egrep 'ansible|openstacksdk'
ansible-2.9.7-1.el7ae.noarch
openshift-ansible-roles-3.11.216-1.git.0.085486a.el7.noarch
python2-openstacksdk-0.11.4-1.el7ost.noarch
openshift-ansible-playbooks-3.11.216-1.git.0.085486a.el7.noarch
openshift-ansible-3.11.216-1.git.0.085486a.el7.noarch
openshift-ansible-docs-3.11.216-1.git.0.085486a.el7.noarch

So, unless I'm missing something, I'd say Ansible-2.9 won't work for the OpenStack related playbooks. 

If I am missing something, please let me know.

There is a docs bug introduced recently ( BZ 1838441 ). I have raised it so we can fast track the PR for the documentation for this bug, which is in another PR: 

https://github.com/openshift/openshift-docs/pull/20705