The following page and section: https://docs.percona.com/postgresql/16/solutions/ha-setup-yum.html#configure-node1 describes how to set up a basic 3-node Patroni cluster. Etcd configuration instruction suggests using environment variables to simplify the configuration. The way it's described now (putting ${ENV_VARIABLE} directly into etcd.conf) doesn't work as etcd throws parsing error, e.g.:

The solution is probably something closer to: