History

Jeremy Stanley fd9c80208c Replace subprocess with run_local in _find_images In the DevStack caching script/element for Nodepool images, use run_local instead of subprocess.check_output in the _find_images function. The latter wasn't introduced until Python 2.7 and so won't work on CentOS 6. The script called from this function returns quickly and doesn't benefit from non-blocking I/O anyway. Change-Id: I3129f1f5b3fece321ae132ea1a52b0e156e58365		2015-05-02 12:17:56 +00:00
..
cache-devstack	Replace subprocess with run_local in _find_images	2015-05-02 12:17:56 +00:00
node-devstack	Move to using package-installs.yaml	2014-12-11 13:48:13 -08:00
nodepool-base	Disable metadata in cloud-init config	2015-03-20 14:13:16 -04:00
openstack-repos	Rename config => system-config for nodepool	2014-10-17 21:28:44 +00:00
puppet	Revert "Remove ssh host keys during image build"	2015-03-20 12:47:10 -04:00
slave-db	Reorganizes project-config	2014-09-25 11:41:04 -04:00
README.rst	Determine CentOS 6 platform in cache-devstack	2015-05-01 20:57:05 +00:00

README.rst

Using diskimage-builder to build devstack-gate nodes

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 diskimage-builder

Install the dependencies:

sudo apt-get install kpartx qemu-utils curl python-yaml

Install diskimage-builder:

sudo -H pip install diskimage-builder

Build an image

Building an image is simple, we have a script!

DISTRO="ubuntu" bash tools/build-image.sh

See the script for environment variables to set distribution, etc. You should be left with a .qcow2 image file of your selected distribution.

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.

Mounting the image

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

Other things

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.