Comment 1 for bug 1577928

To clarify, passing:

cat > env.yaml << EOF
parameter_defaults:
  NtpServer: some_server
EOF

openstack overcloud deploy --templates -e env.yaml

Should be equivalent to:

openstack overcloud deploy --templates --ntp-server some server

This works for single node deployments, but the validation in the patch referenced above is in the wrong place - it should validate the parsed environment, including parameters derived from parameters, not the parameter value directly.