How to integrate a platform as a service with configuration management tools?
A configuration management tool is not required to manage a PAAS. For example, when one has created a VM on Azure then it is possible to export the configuration snippet as powershell or as yaml and use yaml to deploy and manage systems.

In my opinion one should restrict configuration management tools like puppet or ansible to manage configuration files and installing additional packages and yaml to manage the PAAS as I prefer KISS.

If one would like to manage different PASS then one could consider to use terraform.