Path rewriting causes too many problems when vendoring
vendored code. When CNI code is vendored into rkt,
godep has problems code already vendored by CNI.
The plugin binary actually functions in two modes. The first mode
is a regular CNI plugin. The second mode (when stared with "daemon" arg)
runs a DHCP client daemon. When executed as a CNI plugin, it issues
an RPC request to the daemon for actual processing. The daemon is
required since a DHCP lease needs to be maintained by periodically
renewing it. One instance of the daemon can server arbitrary number
of containers/leases.