In order for Patroni to reliably determine or define the identity of the primary PostgreSQL instance, we need a distributed key-value layer. In this recipe, we'll be installing etcd to fulfill that role.
The etcd maintainers appear to have designed it to operate primarily in nameless virtual containers. This means that we just need to download it and place some binaries in appropriate locations. It's not an ideal installation with reliable configuration files and other expected components, but that's easily rectified if we decide to rely on etcd in the long term.
So, let's get started.
