Split Stack Experiments

NOTE: requires https://review.openstack.org/600042

Prototype of a TripleO Split Controlplane deployment.

External Compute

1. Deploy a single controller node with deploy-control-plane.sh
2. Extract control plane information that an "external" compute node would need with create-compute-stack-env.sh
3. Deploy an "external" compute node with a separate heat stack deploy-compute.sh

"Work for me", at least the pingtest does (owalsh)

TODO(owalsh): migration is unlikely to work between computes on different stacks. We will need to propegate ssh_known_hosts to all hosts to resolve this and probably /etc/hosts too until I revert https://review.openstack.org/590362

Based examples from shardy.

Multi-Cell

NOTE requires: https://review.openstack.org/600042 https://review.openstack.org/600588 https://review.openstack.org/600589

1. Deploy a single controller node with deploy-control-plane.sh
2. Extract control plane information that a connected cell v2 controller and compute would need with create-cell-stack-env.sh
3. Deploy a cell controller and compute node with a separate heat stack deploy-cell.sh

Should see the newcompute being added to mycomputecell e.g:

Found 3 cell mappings.
Skipping cell0 since it does not contain hosts.
Getting computes from cell 'default': 1c4883d8-0ab5-422d-95d5-c786bd2caecc
Found 0 unmapped computes in cell: 1c4883d8-0ab5-422d-95d5-c786bd2caecc
Getting computes from cell 'mycomputecell': 3d868a19-5152-4977-8fc4-d87dab2a3cbc
Creating host mapping for service computecell0-novacompute-0.localdomain
Found 1 unmapped computes in cell: 3d868a19-5152-4977-8fc4-d87dab2a3cbc

TODO:

• look at improving how hieradata is passed from parent to child stack (probably need to support multiple generations too)
• probably need to add new t-h-t services instead of hieradata hacks to avoid conflicts with the parent stack services' hieradata
• need a proper solution for /etc/hosts. This is required for cell_v2 as the main stack needs to connect to the cell mq using the fqdn (rabbit will not allow IPs to be used).

Notes

Workaround here for reboot issues with cinder LVM - https://bugzilla.redhat.com/show_bug.cgi?id=1412661#c15