Galera behind NAT (mixed environment in k8s and docker)
Database plays an important role in the application development. To have a redundant and high available database, we can use Galera for mysql/mariadb. With Galera, the database can have replication across different server and the load can be divided into some servers. By that capability, we can have a reliable backend database for our application. In this tutorial, we will deploy galera cluster inside kubernetes and docker. In normal circumstance, when we install galera inside kubernetes, the replication communication is using internal network. So we need to set galera to use external network so that galera cluster can communicate with mariadb outside the kubernetes. With this setup, we can combine galera node located in kubernetes, docker, private or public cloud.