Files
deb-nova/nova/api/ec2/ec2utils.py
2011-09-21 09:34:59 -07:00

138 lines
4.1 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import re
from nova import exception
def ec2_id_to_id(ec2_id):
"""Convert an ec2 ID (i-[base 16 number]) to an instance id (int)"""
try:
return int(ec2_id.split('-')[-1], 16)
except ValueError:
raise exception.InvalidEc2Id(ec2_id=ec2_id)
def id_to_ec2_id(instance_id, template='i-%08x'):
"""Convert an instance ID (int) to an ec2 ID (i-[base 16 number])"""
return template % instance_id
def id_to_ec2_snap_id(instance_id):
"""Convert an snapshot ID (int) to an ec2 snapshot ID
(snap-[base 16 number])"""
return id_to_ec2_id(instance_id, 'snap-%08x')
def id_to_ec2_vol_id(instance_id):
"""Convert an volume ID (int) to an ec2 volume ID (vol-[base 16 number])"""
return id_to_ec2_id(instance_id, 'vol-%08x')
_c2u = re.compile('(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|$)))')
def camelcase_to_underscore(str):
return _c2u.sub(r'_\1', str).lower().strip('_')
def _try_convert(value):
"""Return a non-string from a string or unicode, if possible.
============= =====================================================
When value is returns
============= =====================================================
zero-length ''
'None' None
'True' True case insensitive
'False' False case insensitive
'0', '-0' 0
0xN, -0xN int from hex (postitive) (N is any number)
0bN, -0bN int from binary (positive) (N is any number)
* try conversion to int, float, complex, fallback value
"""
if len(value) == 0:
return ''
if value == 'None':
return None
lowered_value = value.lower()
if lowered_value == 'true':
return True
if lowered_value == 'false':
return False
valueneg = value[1:] if value[0] == '-' else value
if valueneg == '0':
return 0
if valueneg == '':
return value
if valueneg[0] == '0':
if valueneg[1] in 'xX':
return int(value, 16)
elif valueneg[1] in 'bB':
return int(value, 2)
else:
try:
return int(value, 8)
except ValueError:
pass
try:
return int(value)
except ValueError:
pass
try:
return float(value)
except ValueError:
pass
try:
return complex(value)
except ValueError:
return value
def dict_from_dotted_str(items):
"""parse multi dot-separated argument into dict.
EBS boot uses multi dot-separeted arguments like
BlockDeviceMapping.1.DeviceName=snap-id
Convert the above into
{'block_device_mapping': {'1': {'device_name': snap-id}}}
"""
args = {}
for key, value in items:
parts = key.split(".")
key = str(camelcase_to_underscore(parts[0]))
if isinstance(value, str) or isinstance(value, unicode):
# NOTE(vish): Automatically convert strings back
# into their respective values
value = _try_convert(value)
if len(parts) > 1:
d = args.get(key, {})
args[key] = d
for k in parts[1:-1]:
k = camelcase_to_underscore(k)
v = d.get(k, {})
d[k] = v
d = v
d[camelcase_to_underscore(parts[-1])] = value
else:
args[key] = value
return args