bootstrap-vz/bootstrapvz/base/fs/partitions/base.py
Anders Ingemann 33a430566b bootstrap-vz is now a proper python package
logs/ was remove. logs are now placed in /var/logs/bootstrap-vz instead
2014-04-02 23:25:50 +02:00

105 lines
3.6 KiB
Python

from abstract import AbstractPartition
class BasePartition(AbstractPartition):
"""Represents a partition that is actually a partition (and not a virtual one like 'Single')
"""
# Override the states of the abstract partition
# A real partition can be mapped and unmapped
events = [{'name': 'create', 'src': 'nonexistent', 'dst': 'unmapped'},
{'name': 'map', 'src': 'unmapped', 'dst': 'mapped'},
{'name': 'format', 'src': 'mapped', 'dst': 'formatted'},
{'name': 'mount', 'src': 'formatted', 'dst': 'mounted'},
{'name': 'unmount', 'src': 'mounted', 'dst': 'formatted'},
{'name': 'unmap', 'src': 'formatted', 'dst': 'unmapped_fmt'},
{'name': 'map', 'src': 'unmapped_fmt', 'dst': 'formatted'},
{'name': 'unmap', 'src': 'mapped', 'dst': 'unmapped'},
]
def __init__(self, size, filesystem, format_command, previous):
"""
Args:
size (Bytes): Size of the partition
filesystem (str): Filesystem the partition should be formatted with
format_command (list): Optional format command, valid variables are fs, device_path and size
previous (BasePartition): The partition that preceeds this one
"""
# By saving the previous partition we have
# a linked list that partitions can go backwards in to find the first partition.
self.previous = previous
from bootstrapvz.common.bytes import Bytes
# Initialize the offset to 0 bytes, may be changed later
self.offset = Bytes(0)
# List of flags that parted should put on the partition
self.flags = []
super(BasePartition, self).__init__(size, filesystem, format_command)
def create(self, volume):
"""Creates the partition
Args:
volume (Volume): The volume to create the partition on
"""
self.fsm.create(volume=volume)
def get_index(self):
"""Gets the index of this partition in the partition map
Returns:
int. The index of the partition in the partition map
"""
if self.previous is None:
# Partitions are 1 indexed
return 1
else:
# Recursive call to the previous partition, walking up the chain...
return self.previous.get_index() + 1
def get_start(self):
"""Gets the starting byte of this partition
Returns:
Bytes. The starting byte of this partition
"""
if self.previous is None:
# If there is no previous partition, this partition begins at the offset
return self.offset
else:
# Get the end of the previous partition and add the offset of this partition
return self.previous.get_end() + self.offset
def map(self, device_path):
"""Maps the partition to a device_path
Args:
device_path (str): The device patht his partition should be mapped to
"""
self.fsm.map(device_path=device_path)
def _before_create(self, e):
"""Creates the partition
"""
from bootstrapvz.common.tools import log_check_call
# The create command is failry simple, start and end are just Bytes objects coerced into strings
create_command = ('mkpart primary {start} {end}'
.format(start=str(self.get_start()),
end=str(self.get_end())))
# Create the partition
log_check_call(['parted', '--script', '--align', 'none', e.volume.device_path,
'--', create_command])
# Set any flags on the partition
for flag in self.flags:
log_check_call(['parted', '--script', e.volume.device_path,
'--', ('set {idx} {flag} on'
.format(idx=str(self.get_index()), flag=flag))])
def _before_map(self, e):
# Set the device path
self.device_path = e.device_path
def _before_unmap(self, e):
# When unmapped, the device_path ifnromation becomes invalid, so we delete it
self.device_path = None