Now openstack have it own datasource additionnally to the ec2,
and it also supports the configdrive datasource when an instance is booted with:
nova boot --configdrive --user-meta .... vm
# For OpenStack, we would like to use Ec2 and no other API
echo "# to update this file, run dpkg-reconfigure cloud-init
-datasource_list: [ Ec2 ]" >${MOUNT_DIR}/etc/cloud/cloud.cfg.d/90_dpkg.cfg
+datasource_list: [ Ec2, ConfigDrive, OpenStack ]" >${MOUNT_DIR}/etc/cloud/cloud.cfg.d/90_dpkg.cfg
# Needed to have automatic mounts of /dev/vdb
echo "mount_default_fields: [~, ~, 'auto', 'defaults,nofail', '0', '2']" >>${MOUNT_DIR}/etc/cloud/cloud.cfg