Description of problem: The openstack-heat-agents package installs a significant number of dependencies, none of which have been required by OSP/TripleO directly for some time (since stable/wallaby aka OSP 17.x at the very least). Partner/Customer integrations could be using these. The preferred method of integration is to use Ansible instead. As noted in https://review.opendev.org/c/openstack/tripleo-common/+/838633 (present in stable/zed aka OSP 18.0) there is no OSP-native requirement for the heat agents any more. We should ideally deprecate the inclusion of this package in the overcloud base image in OSP 17.1 and remove it in OSP 18.0. We should also consider deprecating the interface in OSP 17.1 and stopping support for it in OSP 18.0. To do this may require some changes to the partner integration documentation [a] and the example integration repository [b]. [a] https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/17.0/html/partner_integration/index [b] https://github.com/redhat-openstack/tripleo-example-integration
AFAIK the heat-agent package is still required for the ExtraConfigPre/Post resources. If we aim to remove the package then we should implement an anternative interface to implement the same pre/post configuration hook.
I think before proposing to drop the package from overcloud image, As Takashi mentioned, we need to either replace/drop interface and provide a way for users to migrate.
FTR, we need another bz for removing puppet from overcloud images, and moving it/modules to the corresponding components' base container images.