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1 | bd924ffd | Dimitris Aragiorgis | #!/usr/bin/env python |
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2 | bd924ffd | Dimitris Aragiorgis | # |
3 | bd924ffd | Dimitris Aragiorgis | # Copyright (C) 2012 Greek Research and Technology Network |
4 | bd924ffd | Dimitris Aragiorgis | # |
5 | bd924ffd | Dimitris Aragiorgis | # This program is free software; you can redistribute it and/or modify |
6 | bd924ffd | Dimitris Aragiorgis | # it under the terms of the GNU General Public License as published by |
7 | bd924ffd | Dimitris Aragiorgis | # the Free Software Foundation; either version 2 of the License, or |
8 | bd924ffd | Dimitris Aragiorgis | # (at your option) any later version. |
9 | bd924ffd | Dimitris Aragiorgis | # |
10 | bd924ffd | Dimitris Aragiorgis | # This program is distributed in the hope that it will be useful, but |
11 | bd924ffd | Dimitris Aragiorgis | # WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | bd924ffd | Dimitris Aragiorgis | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | bd924ffd | Dimitris Aragiorgis | # General Public License for more details. |
14 | bd924ffd | Dimitris Aragiorgis | # |
15 | bd924ffd | Dimitris Aragiorgis | # You should have received a copy of the GNU General Public License |
16 | bd924ffd | Dimitris Aragiorgis | # along with this program; if not, write to the Free Software |
17 | bd924ffd | Dimitris Aragiorgis | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
18 | bd924ffd | Dimitris Aragiorgis | # 02110-1301, USA. |
19 | bd924ffd | Dimitris Aragiorgis | |
20 | bd924ffd | Dimitris Aragiorgis | """Detach the Image file from the loop device |
21 | bd924ffd | Dimitris Aragiorgis | |
22 | bd924ffd | Dimitris Aragiorgis | This program detaches an Image file from the loop device it attached to. |
23 | bd924ffd | Dimitris Aragiorgis | It is idempotent, if the file isn't losetup at all. |
24 | bd924ffd | Dimitris Aragiorgis | |
25 | bd924ffd | Dimitris Aragiorgis | It takes it's input from environment variables. Specifically the |
26 | bd924ffd | Dimitris Aragiorgis | following variable should be present: |
27 | bd924ffd | Dimitris Aragiorgis | |
28 | bd924ffd | Dimitris Aragiorgis | - VOL_NAME: The name of the Image file to which the device points |
29 | bd924ffd | Dimitris Aragiorgis | |
30 | bd924ffd | Dimitris Aragiorgis | Returns O upon successfull unmapping, 1 upon failure |
31 | bd924ffd | Dimitris Aragiorgis | |
32 | bd924ffd | Dimitris Aragiorgis | """ |
33 | bd924ffd | Dimitris Aragiorgis | |
34 | bd924ffd | Dimitris Aragiorgis | import os |
35 | bd924ffd | Dimitris Aragiorgis | import sys |
36 | bd924ffd | Dimitris Aragiorgis | |
37 | 68abdf0d | Dimitris Aragiorgis | sys.path.insert(0, "/etc/ganeti/share") |
38 | bd924ffd | Dimitris Aragiorgis | |
39 | bd924ffd | Dimitris Aragiorgis | from ganeti import utils |
40 | bd924ffd | Dimitris Aragiorgis | |
41 | bd924ffd | Dimitris Aragiorgis | |
42 | bd924ffd | Dimitris Aragiorgis | # Default shared directory |
43 | bd924ffd | Dimitris Aragiorgis | SHARED_DIR = "/srv/ganeti/shared-file-storage" |
44 | bd924ffd | Dimitris Aragiorgis | |
45 | bd924ffd | Dimitris Aragiorgis | |
46 | bd924ffd | Dimitris Aragiorgis | def ReadEnv(): |
47 | bd924ffd | Dimitris Aragiorgis | """Read the mandatory enviromental variables |
48 | bd924ffd | Dimitris Aragiorgis | |
49 | bd924ffd | Dimitris Aragiorgis | """ |
50 | bd924ffd | Dimitris Aragiorgis | name = os.getenv("VOL_NAME") |
51 | bd924ffd | Dimitris Aragiorgis | if name is None: |
52 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('The environment variable VOL_NAME is missing.\n') |
53 | bd924ffd | Dimitris Aragiorgis | return None |
54 | bd924ffd | Dimitris Aragiorgis | shared_dir_param = os.getenv("EXTP_SHARED_DIR") |
55 | bd924ffd | Dimitris Aragiorgis | if shared_dir_param is not None: |
56 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('Found shared dir param, value: %s\n' % shared_dir_param) |
57 | bd924ffd | Dimitris Aragiorgis | |
58 | bd924ffd | Dimitris Aragiorgis | return (name, shared_dir_param) |
59 | bd924ffd | Dimitris Aragiorgis | |
60 | bd924ffd | Dimitris Aragiorgis | |
61 | bd924ffd | Dimitris Aragiorgis | def _ParseLosetupOutput(output, filename): |
62 | bd924ffd | Dimitris Aragiorgis | """Parse the output of `losetup -j <filename>` |
63 | bd924ffd | Dimitris Aragiorgis | |
64 | bd924ffd | Dimitris Aragiorgis | This method parses the output of `losetup -j <filename>` and returns |
65 | bd924ffd | Dimitris Aragiorgis | the corresponding loop device path for this filename |
66 | bd924ffd | Dimitris Aragiorgis | (e.g. /dev/loop0) |
67 | bd924ffd | Dimitris Aragiorgis | |
68 | bd924ffd | Dimitris Aragiorgis | @type output: string |
69 | bd924ffd | Dimitris Aragiorgis | @param output: the whole output of `losetup -j filename` |
70 | bd924ffd | Dimitris Aragiorgis | @type filename: string |
71 | bd924ffd | Dimitris Aragiorgis | @param filename: the complete file path to the file we search for |
72 | bd924ffd | Dimitris Aragiorgis | @rtype: string or None |
73 | bd924ffd | Dimitris Aragiorgis | @return: loop device path if the file is losetup, else None |
74 | bd924ffd | Dimitris Aragiorgis | |
75 | bd924ffd | Dimitris Aragiorgis | """ |
76 | bd924ffd | Dimitris Aragiorgis | # `losetup -j file1` output looks like this |
77 | bd924ffd | Dimitris Aragiorgis | # /dev/loop0: [X]:Y (/path/to/file1) |
78 | bd924ffd | Dimitris Aragiorgis | # if the file has been losetup. If not there is no output. |
79 | bd924ffd | Dimitris Aragiorgis | # If the file has been losetup more than once, then there will be |
80 | bd924ffd | Dimitris Aragiorgis | # multiple lines like the one above. |
81 | bd924ffd | Dimitris Aragiorgis | # |
82 | bd924ffd | Dimitris Aragiorgis | # We assume the following format (space is the seperator): |
83 | bd924ffd | Dimitris Aragiorgis | # field0: field1 (field2) |
84 | bd924ffd | Dimitris Aragiorgis | |
85 | bd924ffd | Dimitris Aragiorgis | field0 = 0 |
86 | bd924ffd | Dimitris Aragiorgis | field_sep = " " |
87 | bd924ffd | Dimitris Aragiorgis | |
88 | bd924ffd | Dimitris Aragiorgis | lines = output.splitlines() |
89 | bd924ffd | Dimitris Aragiorgis | splitted_lines = map(lambda l: l.split(field_sep), lines) |
90 | bd924ffd | Dimitris Aragiorgis | |
91 | bd924ffd | Dimitris Aragiorgis | # Check empty output. If empty, the file is not losetup |
92 | bd924ffd | Dimitris Aragiorgis | if not splitted_lines: |
93 | bd924ffd | Dimitris Aragiorgis | return None |
94 | bd924ffd | Dimitris Aragiorgis | |
95 | bd924ffd | Dimitris Aragiorgis | # Check if we have more than one lines in the output |
96 | bd924ffd | Dimitris Aragiorgis | if len(splitted_lines) > 1: |
97 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write("The file %s is losetup more than once" % filename) |
98 | bd924ffd | Dimitris Aragiorgis | sys.exit(1) |
99 | bd924ffd | Dimitris Aragiorgis | |
100 | bd924ffd | Dimitris Aragiorgis | # The file is losetup only once |
101 | bd924ffd | Dimitris Aragiorgis | # Take field0, remove the ":" at the end and we have our path |
102 | bd924ffd | Dimitris Aragiorgis | dev_path = splitted_lines[0][field0].split(":")[0] |
103 | bd924ffd | Dimitris Aragiorgis | |
104 | bd924ffd | Dimitris Aragiorgis | return dev_path |
105 | bd924ffd | Dimitris Aragiorgis | |
106 | bd924ffd | Dimitris Aragiorgis | |
107 | bd924ffd | Dimitris Aragiorgis | def main(): |
108 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('Detaching started: reading environment...\n') |
109 | bd924ffd | Dimitris Aragiorgis | |
110 | bd924ffd | Dimitris Aragiorgis | # Read environment |
111 | bd924ffd | Dimitris Aragiorgis | env = ReadEnv() |
112 | bd924ffd | Dimitris Aragiorgis | if env is None: |
113 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('Wrong environment. Aborting\n') |
114 | bd924ffd | Dimitris Aragiorgis | return 1 |
115 | bd924ffd | Dimitris Aragiorgis | |
116 | bd924ffd | Dimitris Aragiorgis | file_name, shared_dir_param = env |
117 | bd924ffd | Dimitris Aragiorgis | |
118 | bd924ffd | Dimitris Aragiorgis | if shared_dir_param is None: |
119 | bd924ffd | Dimitris Aragiorgis | shared_dir_param = SHARED_DIR |
120 | bd924ffd | Dimitris Aragiorgis | |
121 | bd924ffd | Dimitris Aragiorgis | file_path = utils.PathJoin(shared_dir_param, file_name) |
122 | bd924ffd | Dimitris Aragiorgis | |
123 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('Read environment successfully: file name: %s\n' % file_path) |
124 | bd924ffd | Dimitris Aragiorgis | |
125 | bd924ffd | Dimitris Aragiorgis | # Check if the file exists |
126 | bd924ffd | Dimitris Aragiorgis | if not os.path.exists(file_path): |
127 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('File %s does not exist. Aborting\n' % file_path) |
128 | bd924ffd | Dimitris Aragiorgis | return 1 |
129 | bd924ffd | Dimitris Aragiorgis | |
130 | bd924ffd | Dimitris Aragiorgis | # Check if the file is losetup |
131 | bd924ffd | Dimitris Aragiorgis | cmd1 = ["losetup", "-j", "%s" % file_path] |
132 | bd924ffd | Dimitris Aragiorgis | result = utils.RunCmd(cmd1) |
133 | bd924ffd | Dimitris Aragiorgis | if result.failed: |
134 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('losetup -j %s failed (%s): %s' % |
135 | bd924ffd | Dimitris Aragiorgis | (dev_path, result.fail_reason, result.output)) |
136 | bd924ffd | Dimitris Aragiorgis | return 1 |
137 | bd924ffd | Dimitris Aragiorgis | else: |
138 | bd924ffd | Dimitris Aragiorgis | # Parse the result's output |
139 | bd924ffd | Dimitris Aragiorgis | dev_path = _ParseLosetupOutput(result.output, file_path) |
140 | bd924ffd | Dimitris Aragiorgis | |
141 | bd924ffd | Dimitris Aragiorgis | if dev_path is None: |
142 | bd924ffd | Dimitris Aragiorgis | # The file is not losetup (device is not attached). Return. |
143 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('File %s successfully detached\n' % file_path) |
144 | bd924ffd | Dimitris Aragiorgis | return 0 |
145 | bd924ffd | Dimitris Aragiorgis | else: |
146 | bd924ffd | Dimitris Aragiorgis | # The file is losetup (device attached). Detach it. |
147 | bd924ffd | Dimitris Aragiorgis | cmd2 = ["losetup", "-d", "%s" % dev_path] |
148 | bd924ffd | Dimitris Aragiorgis | result = utils.RunCmd(cmd2) |
149 | bd924ffd | Dimitris Aragiorgis | if result.failed: |
150 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('Cannot `losetup -d` device: %s, detachment failed ' |
151 | bd924ffd | Dimitris Aragiorgis | '(%s): %s\n' % |
152 | bd924ffd | Dimitris Aragiorgis | (dev_path, result.fail_reason, result.output)) |
153 | bd924ffd | Dimitris Aragiorgis | return 1 |
154 | bd924ffd | Dimitris Aragiorgis | |
155 | bd924ffd | Dimitris Aragiorgis | sys.stderr.write('File %s successfully detached\n' % file_path) |
156 | bd924ffd | Dimitris Aragiorgis | return 0 |
157 | bd924ffd | Dimitris Aragiorgis | |
158 | bd924ffd | Dimitris Aragiorgis | |
159 | bd924ffd | Dimitris Aragiorgis | if __name__ == "__main__": |
160 | bd924ffd | Dimitris Aragiorgis | sys.exit(main()) |