Speeding up DevStack with a JeOS template
As XenServer runs all the OpenStack services in a separate VM, DevStack needs to install a new operating system during its first run. This is achieved by performing a netinstall with a preseed file. If you use DevStack in a CI environment, you most probably start each DevStack execution with an empty hypervisor. To speed up such scenarios, you can re-use a JeOS template from a previous DevStack run.
To achieve this, we provide a script that can be downloaded from GitHub.
To export the JeOS template after a successful DevStack run, use:
./install-devstack-xen.sh $HOST $XenServerPassword devstack_key.priv -e external-precise.xva
The exported xva could be shared on a webserver, and it could be re-used later. As an example, in our CI, we use this command line to execute devstack:
./install-devstack-xen.sh $HOST $XenServerPassword devstack_key.priv -j http://[path-to-webserver]/external-precise.xva
This significantly speeds up the devstack execution.