Comment 9 for bug 1640815

For general reference, summarised from IRC: the CLI eventually will store the environments in the same way than the UI (aka will need this fix too), but cannot at the moment for backwards-compatibility reasons. Custom environments deployed with the CLI can include relative paths [1], which means an env could reference files anywhere locally. For this to continue to work, heatclient is used to discovered all the referenced files, which is how we end up with a merged environment.

[1] https://github.com/openstack/tripleo-heat-templates/blob/master/environments/net-bond-with-vlans.yaml