The PostgreSQL Operator is now available in the https://operatorhub.io and in a good state for you.
Note that it was NOT just developed to provide a comfortable and flexible Operator to install and manage a PostgreSQL with Backup features on Kubernetes cluster. The primary motivation to do it was to provide a good example over how to do operators using Operator-SDK and the Operator-Framework. This project is covering the usage of its main features, and I hope that it helps you as well.
Please, feel free to check its code source in https://github.com/dev4devs-com/postgresql-operator as use and contribute with.