Including an additional element is inconvenient

[Steven Hardy]

Currently we have several handy options to overcloud image build in tripleoclient, for example you might want to do this:

git clone https://github.com/openstack/tripleo-puppet-elements.git

<hack on a fancy-new-element element>

export NODE_DIST=centos7

openstack overcloud image build --type overcloud-full --tripleo-puppet-elements /home/stack/tripleo-puppet-elements --overcloud-full-dib-extra-args "fancy-new-element"

However, this doesn't work as expected - the extra-args overwrites the internally defined extra-args instead of appending to them, so we don't build all of the normal openstack elements into the image. Same problem when you export OVERCLOUD_FULL_DIB_EXTRA_ARGS.

To support third-party integrators who may want to build their additional elements into the image, we need a simple way to append extra elements to those normally built, or at least an obvious way to see what is normally defined internally (such as a warning when you call with the overcloud-full-dib-extra-args option, showing the list of elements overwritten so they can be cut/pasted into the CLI).

[Steven Hardy (shardy)]

Note the workaround is to derive the list of extra args from the logs, and pass in a fully qualified list, e.g:

openstack overcloud image build --type overcloud-full --tripleo-puppet-elements /home/stack/tripleo-puppet-elements --overcloud-full-dib-extra-args "overcloud-full overcloud-controller overcloud-compute overcloud-ceph-storage ntp sysctl hosts baremetal dhcp-all-interfaces os-collect-config heat-config-puppet heat-config-script puppet-modules hiera os-net-config stable-interface-names grub2-deprecated "

Clearly this will be fragile because folks won't know if the internally defined list changes.

[Steven Hardy (shardy)]

I think this is actually fixed by https://review.openstack.org/#/c/229778/

I made some notes of how I pulled and tested that via building a local delorean package:

http://paste.openstack.org/show/475605/

[Ben Nemec (bnemec)]

IMHO https://review.openstack.org/#/c/229778/ mitigates the problem, but I'd still like to see the behavior of overcloud-full-dib-extra-args fixed. It's clearly wrong based on the name of the option, and third-party integrators aren't necessarily going to want their extra elements running on ramdisk image builds, which is what that change will do. I'm fine with both options existing because I think there are valid use cases for both, but I don't know that one can replace the other.

[Brad P. Crochet (brad-9)]

I would like to think that this is basically fixed by the use of tripleo-build-images. The yaml definition files are *far* superior to the imperative building approach. There are two final reviews to really have this switched: https://review.openstack.org/#/c/336312/ and https://review.openstack.org/#/c/337669/