Kubernetes is an open source container orchestration platform for automating deployment, scaling and management of application containers. Nowadays, more and more applications are being deployed in containers on Kubernetes. However, managing database on Kubernetes is difficult because the data redundancy can have very specific requirements. There are several solutions that can help us to run a PostgreSQL HA cluster on Kubernetes. However, these solutions don't provide query load balancing functionality. Therefore, users need to modify the application to distribute read queries among multiple PostgreSQL containers. In this talk, I would like to give you an overview of Kubernetes and explain how to deploy a PostgreSQL HA cluster with query load balancing using Pgpool-II on Kubernetes. Although Kubernetes provides a way to monitor the basic cluster status, this is not sufficient for practical cluster management. In this talk, I will introduce the way to implement custom Prometheus metrics to monitor PostgreSQL cluster status and performance for extensive cluster monitoring.