At the moment the `openstack overcloud deploy` command accepts the `--environment-file` (short version `-e`) argument. This is for providing additional Heat environment files for the deployment. The problem with these files is that they can reference files in the resource registry anywhere on the local filesystem. To find these files we need to process the templates with python-heatclient (to avoid manually parsing and following them).
The files also have local file paths which don't make sense when the files are uploaded to swift.
We need a better way for this to work. A possible solution would be for the user to put all the files in one directory and tell the deploy command about them with an argument something like `--environment-dir`. Then all files would be uploaded without any processing.
There are some questions.
1. Do we allow users to provide multiple environment directories?
2. How do we merge the environment directory with the tripleo-heat-templates root? Do we just overwrite any files that are the same?
3. Does this have any impact on the GUI?
As a somewhat related reference, bug 1642583 was filed against the UI as it cannot display which environments were enabled if the deployment was launched from the CLI. (Currently the UI shows e.g. "Storage Environment, Base resources configuration, TLS, SSL-enabled deployment with IP address as public endpoint, environments/