We've merged our docker and pulp 2.5 changes into katello master. There were no code changes necessary to support 2.5.
To upgrade, enable the pulp beta repo. Additionally, the pulp betas should be in the katello nightly repos too.
After you've enabled the repos, run:
sudo yum update pulp
To get the docker pulp packages, you'll want to install them:
yum install python-crane pulp-docker-plugins
yum install pulp-docker-admin-extensions (if using pulp-admin)
Then upgrade your database:
sudo -u apache pulp-manage-db
And then restart the pulp services:
for x in httpd pulp_resource_manager pulp_celerybeat pulp_workers
sudo service $x restart
Also, there are some changes to the katello-installer to setup/configure docker and crane but the PRs have not been merged yet.