Commit ba74928 by
@davidopp says:
Have etcd listen on all interfaces so that monit probes succeed. Closes #3852.

Listening on all interfaces is the wrong thing to do from a security standpoint because it exposes etcd to modification.

Once @ArtfulCoder change to put etcd in a pod is complete, then kubelet can monitor instead of monit, so then etc can be on 127.0.0.1.

It is confusing, because DAEMON_ARGS is set in cluster/saltbase/salt/etcd/defaults, which is where you normally set those things. But that file is only pushed to the node by cluster/saltbase/salt/etcd/init.sls if the OS is red-hat. What a mess.