+<%
+dockerd = '/usr/bin/dockerd'
+# old daemon command
+dockerd = '/usr/bin/docker daemon' unless File.exist?(dockerd)
+-%>
[Service]
ExecStart=
-ExecStart=/usr/bin/docker daemon <%= @docker_opts.join(' ') %>
+ExecStart=<%= dockerd %> <%= @docker_opts.join(' ') %>