def GetBlockDeviceMap(machine_type,
root_volume_size_gb=None,
image_id=None,
region=None):
"""Returns the block device map to expose all devices for a given machine.
Args:
machine_type: The machine type to create a block device map for.
root_volume_size_gb: The desired size of the root volume, in GiB,
or None to the default provided by AWS.
image_id: The image id (AMI) to use in order to lookup the default
root device specs. This is only required if root_volume_size
is specified.
region: The region which contains the specified image. This is only
required if image_id is specified.
Returns:
The json representation of the block device map for a machine compatible
with the AWS CLI, or if the machine type has no local disks, it will
return None. If root_volume_size_gb and image_id are provided, the block
device map will include the specification for the root volume.
Raises:
ValueError: If required parameters are not passed.
"""
mappings = []
if root_volume_size_gb is not None:
if image_id is None:
raise ValueError(
'image_id must be provided if root_volume_size_gb is specified'
)
if region is None:
raise ValueError(
'region must be provided if image_id is specified')
root_block_device = GetRootBlockDeviceSpecForImage(image_id, region)
root_block_device['Ebs']['VolumeSize'] = root_volume_size_gb
# The 'Encrypted' key must be removed or the CLI will complain
root_block_device['Ebs'].pop('Encrypted')
mappings.append(root_block_device)
if (machine_type in NUM_LOCAL_VOLUMES
and not aws_disk.LocalDriveIsNvme(machine_type)):
for i in xrange(NUM_LOCAL_VOLUMES[machine_type]):
od = OrderedDict()
od['VirtualName'] = 'ephemeral%s' % i
od['DeviceName'] = '/dev/xvd%s' % chr(ord(DRIVE_START_LETTER) + i)
mappings.append(od)
if mappings:
return json.dumps(mappings)
return None
def _GetNvmeBootIndex(self):
if aws_disk.LocalDriveIsNvme(self.machine_type) and \
aws_disk.EbsDriveIsNvme(self.machine_type):
# identify boot drive
cmd = 'lsblk | grep "part /$" | grep -o "nvme[0-9]*"'
boot_drive = self.RemoteCommand(cmd, ignore_failure=True)[0].strip()
if len(boot_drive) > 0:
# get the boot drive index by dropping the nvme prefix
boot_idx = int(boot_drive[4:])
logging.info('found boot drive at nvme index %d', boot_idx)
return boot_idx
else:
# boot drive is not nvme
return 0
def _GetNvmeBootIndex(self):
if aws_disk.LocalDriveIsNvme(self.machine_type) and \
aws_disk.EbsDriveIsNvme(self.machine_type):
# identify boot drive
# If this command ever fails consider 'findmnt -nM / -o source'
cmd = ('realpath /dev/disk/by-label/cloudimg-rootfs '
'| grep --only-matching "nvme[0-9]*"')
boot_drive = self.RemoteCommand(cmd, ignore_failure=True)[0].strip()
if boot_drive:
# get the boot drive index by dropping the nvme prefix
boot_idx = int(boot_drive[4:])
logging.info('found boot drive at nvme index %d', boot_idx)
return boot_idx
else:
logging.warning('Failed to identify NVME boot drive index. Assuming 0.')
return 0
