heatclient should accept multiple environment files

[Peter Belanyi]

Currently heatclient accepts only one environment file, while it would be useful to accept more than one (in tripleo we would like to pass in several enviroment files, e.g. 1 containing parameters, 1 for resource mapping).

heatclient loads the env file and passes its contents to the api as a dictionary, so it seems possible to process several files, merge the resulting dicts and send it to the api.

[Steven Hardy (shardy)]

To clarify, this is about adding some convenience preprocessing to python-heatclient, not modifying the heat API right?

If so, then this should be marked as affecting python-heatclient not heat.

Also, can you outline how you expect to handle the merge strategy, in the event of collisions between the environment files to be merged?

[Peter Belanyi (pbelanyi)]

You are right, it only affects python-heatclient. I have already submitted a patch: https://review.openstack.org/110984

In my patch I chose to process the environment files in the order they appear on the command line, and have the newer values overwrite the old ones in case of collisions.

[Unmesh Gurjar (unmesh-gurjar)]

Just a thought: (IMO) Collisions are accidental. So, (only) in case of a collision, would it be good to show the user the final value that will be used and give him a chance to confirm before proceeding with the operation?

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/110984
Committed: https://git.openstack.org/cgit/openstack/python-heatclient/commit/?id=b3d350ad3e5776875b24ef63e1ff3a5d1ba87531
Submitter: Jenkins
Branch: master

commit b3d350ad3e5776875b24ef63e1ff3a5d1ba87531
Author: root <email address hidden>
Date: Thu Jul 31 09:07:37 2014 -0400

    Add support for multiple environment files

    This patch adds support for heat to accept multiple -e commandline
    arguments. The environment files are merged, with newer values
    overwriting older ones.

    Change-Id: I01e2baf8dea3bafb1ac6eac34f281c5ff86bf4aa
    Closes-Bug: 1350403