Enable 'delete volume on termination'

[mikery]

http://boto.cloudhackers.com/en/latest/ref/ec2.html#boto.ec2.connection.EC2Connection.modify_instance_attribute

Should be an optional setting in the volumes dict, delete_on_termination, True by default.

[tschellenbach]

Some info on this:
boto/boto#542
boto/boto#1023
boto/boto#820
http://itsecureadmin.com/2011/06/aws-instance-ebs-volume-delete-on-termination/

Something like this might work:

# get the current mapping
mapping = ec2,get_instance_attribute('i-xxxxxxxx', 'BlockDeviceMapping')
# remove the current value
new_mapping = set(mapping) - set('/dev/sda=false', '/dev/sda=true')
# add the new value
new_mapping = list(new_mapping) + ['/dev/sda=true']
# write the new mapping
ec2.modify_instance_attribute('i-xxxxxxxx', 'BlockDeviceMapping', ['/dev/sda=false', '/dev/sdb=true']

Not sure though, doesn't seem very forward compatible.