The walctl toolkit provides two extra scripts that a DBA should never have to call manually: walctl_push and walctl_pull. These are purely intended to facilitate the preferred architecture of walctl. However, we also understand that many PostgreSQL servers exist already, and not every cluster is new.
It's actually very likely that at least one clone exists now and that such behavior is directly supported by PostgreSQL 9.1 and more. In this recipe, we'll explore how to convert an existing cluster to use walctl for WAL management instead.