A static mechanism is the easiest way to set up a cluster. However, the IP address of every member should be known beforehand. This means that if you bootstrap an etcd cluster in a cloud provider environment, the static mechanism might not be so practical. Therefore, etcd also provides a discovery mechanism to bootstrap itself from the existing cluster.
To make etcd communications secure, etcd supports TLS channels to encrypt the communication between peers, and also clients and servers. Each member needs to have a unique key pair. In this section, we'll show you how to use automatically generated certificates to build a cluster.
In CoreOs GitHub, there is a handy tool we can use to generate self-signed certificates (