1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
#
# 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 json
import os
import subprocess
import tempfile
from oslo_log import log
logger = log.getLogger('os-collect-config')
PROC_MOUNTS_PATH = '/proc/mounts'
class BlockDevice:
devname = None
type = None
label = None
mountpoint = None
unmount = False
ATTR_MAP = {
'DEVNAME': 'devname',
'TYPE': 'type',
'LABEL': 'label'
}
@staticmethod
def parse_shell_var(line):
# parse shell-style KEY=value
try:
ieq = line.index('=')
except (ValueError, AttributeError):
return None, None
value = line[ieq + 1:]
# unescape backslash escaped spaces
value = value.replace('\\ ', ' ')
return line[:ieq], value
@classmethod
def from_blkid_export(cls, export_str):
'''Construct BlockDevice from export formatted blkid output.'''
bd = cls()
for line in export_str.splitlines():
var, value = cls.parse_shell_var(line)
if var in cls.ATTR_MAP:
setattr(bd, cls.ATTR_MAP[var], value)
return bd
def config_drive_candidate(self):
'''Whether this block device is a v2 config-drive.'''
return self.label == 'config-2' and self.type in (
'vfat', 'iso9660')
def ensure_mounted(self):
'''Finds an existing mountpoint or mounts to a temp directory.'''
self.unmount = False
# check if already mounted, if so use that
with open(PROC_MOUNTS_PATH) as f:
for line in f.read().splitlines():
values = line.split()
if values[0] == self.devname:
self.mountpoint = values[1]
logger.debug('Found existing mounted config-drive: %s' %
self.mountpoint)
return
# otherwise mount readonly to a temp directory
self.mountpoint = tempfile.mkdtemp(prefix='config-2-')
cmd = ['mount', self.devname, self.mountpoint, '-o', 'ro']
logger.debug('Mounting {} at : {}'.format(
self.devname, self.mountpoint))
try:
subprocess.check_output(cmd)
except subprocess.CalledProcessError as e:
logger.error('Problem running "%s": %s', ' '.join(cmd), e)
os.rmdir(self.mountpoint)
self.mountpoint = None
else:
self.unmount = True
def cleanup(self):
'''Unmounts device if mounted by ensure_mounted.'''
if not self.unmount:
self.mountpoint = None
return
if not self.mountpoint:
self.unmount = False
return
cmd = ['umount', '-l', self.mountpoint]
logger.debug('Unmounting: %s' % self.mountpoint)
try:
subprocess.check_output(cmd)
except subprocess.CalledProcessError as e:
logger.error('Problem running "%s": %s', ' '.join(cmd), e)
else:
os.rmdir(self.mountpoint)
self.mountpoint = None
self.unmount = False
def get_metadata(self):
'''Load and return ec2/latest/meta-data.json from config drive.'''
try:
self.ensure_mounted()
if not self.mountpoint:
return {}
md_path = os.path.join(self.mountpoint,
'ec2', 'latest', 'meta-data.json')
if not os.path.isfile(md_path):
logger.warn('No expected file at path: %s' % md_path)
return {}
with open(md_path) as f:
return json.load(f)
except Exception as e:
logger.error('Problem getting metadata: %s', e)
return {}
finally:
self.cleanup()
def __repr__(self):
return '{}: TYPE="{}" LABEL="{}"'.format(self.devname,
self.type,
self.label)
def all_block_devices():
'''Run blkid and yield a BlockDevice for all devices.'''
try:
cmd = ['blkid', '-o', 'export']
out = subprocess.check_output(cmd, universal_newlines=True)
except Exception as e:
logger.error('Problem running "%s": %s', ' '.join(cmd), e)
else:
# with -o export, devices are separated by a blank line
for device in out.split('\n\n'):
yield BlockDevice.from_blkid_export(device)
def config_drive():
"""Return the first device expected to contain a v2 config drive.
Disk needs to be:
* either vfat or iso9660 formated
* labeled with 'config-2'
"""
for bd in all_block_devices():
if bd.config_drive_candidate():
return bd
def get_metadata():
"""Return discovered config drive metadata, or an empty dict."""
bd = config_drive()
if bd:
return bd.get_metadata()
return {}
|
