In addition to being able to just download and consume images that are the same as what run devstack-gate, it's easy to make your own for local dev or testing - or just for fun.
Install the dependencies:
sudo apt-get install kpartx qemu-utils curl python-yaml debootstrap
sudo -H pip install diskimage-builder
Building an image is simple, we have a script!
See the script for environment variables to set distribution, etc. By default it builds an ubuntu-minimal based image. You should be left with a .qcow2 image file of your selected distribution.
Infra uses the -minimal build type for building Ubuntu/CentOS/Fedora. For example: ubuntu-minimal.
It is a good idea to set
TMP_DIR to somewhere with plenty of space to avoid the disappointment of a full-disk mid-way through the script run.
While testing, consider exporting DIB_OFFLINE=true, to skip updating the cache.
If you would like to examine the contents of the image, you can mount it on a loopback device using qemu-nbd.
sudo apt-get install qemu-utils sudo modprobe nbd max_part=16 sudo mkdir -p /tmp/newimage sudo qemu-nbd -c /dev/nbd1 /path/to/devstack-gate-precise.qcow2 sudo mount /dev/nbd1p1 /tmp/newimage
or use the scripts
sudo apt-get install qemu-utils sudo modprobe nbd max_part=16 sudo tools/mount-image.sh devstack-gate-precise.qcow2 sudo tools/umount-image.sh
It's a qcow2 image, so you can do tons of things with it. You can upload it to glance, you can boot it using kvm, and you can even copy it to a cloud server, replace the contents of the server with it and kexec the new kernel.