我只知道python的基础知识。我有这个项目的信息存储和管理主题。我必须解释下面的代码。
我搜索了此脚本中使用的每个命令，但找不到大多数命令。代码可以找到here：
import glob
import json
import os
import re
import string
import sys
from oslo.config import cfg
from nova import context
from nova.db.sqlalchemy import api as db_api
from nova.db.sqlalchemy import models
from nova import utils
CONF = cfg.CONF
def usage():
print("""
Usage:
python %s --config-file /etc/nova/nova.conf
Note: This script intends to clean up the iSCSI multipath faulty devices
hosted by VNX Block Storage.""" % sys.argv[0])
class FaultyDevicesCleaner(object):
def __init__(self):
# Get host name of Nova computer node.
self.host_name = self._get_host_name()
def _get_host_name(self):
(out, err) = utils.execute('hostname')
return out
def _get_ncpu_emc_target_info_list(self):
target_info_list = []
# Find the targets used by VM on the compute node
bdms = db_api.model_query(context.get_admin_context(),
models.BlockDeviceMapping,
session = db_api.get_session())
bdms = bdms.filter(models.BlockDeviceMapping.connection_info != None)
bdms = bdms.join(models.BlockDeviceMapping.instance).filter_by(
host=string.strip(self.host_name))
for bdm in bdms:
conn_info = json.loads(bdm.connection_info)
if 'data' in conn_info:
if 'target_iqns' in conn_info['data']:
target_iqns = conn_info['data']['target_iqns']
target_luns = conn_info['data']['target_luns']
elif 'target_iqn' in conn_info['data']:
target_iqns = [conn_info['data']['target_iqn']]
target_luns = [conn_info['data']['target_lun']]
else:
target_iqns = []
target_luns = []
for target_iqn, target_lun in zip(target_iqns, target_luns):
if 'com.emc' in target_iqn:
target_info = {
'target_iqn': target_iqn,
'target_lun': target_lun,
}
target_info_list.append(target_info)
return target_info_list
def _get_ncpu_emc_target_info_set(self):
target_info_set = set()
for target_info in self._get_ncpu_emc_target_info_list():
target_iqn = target_info['target_iqn']
target_lun = target_info['target_lun']
target_info_key = "%s-%s" % (target_iqn.rsplit('.', 1)[0],
target_lun)
# target_iqn=iqn.1992-04.com.emc:cx.fnm00130200235.a7
# target_lun=203
# target_info_key=iqn.1992-04.com.emc:cx.fnm00130200235-203
target_info_set.add(target_info_key)
return target_info_set
def _get_target_info_key(self, path):
temp_tuple = path.split('-lun-', 1)
target_lun = temp_tuple[1]
target_iqn = temp_tuple[0].split('-iscsi-')[1]
target_info_key = "%s-%s" % (target_iqn.rsplit('.', 1)[0], target_lun)
# path=/dev/disk/by-path/ip-192.168.3.52:3260-iscsi-iqn.1992-
# 04.com.emc:cx.fnm00130200235.a7-lun-203
# target_info_key=iqn.1992-04.com.emc:cx.fnm00130200235-203
return target_info_key
def _get_non_ncpu_target_info_map(self):
# Group the paths by target_info_key
ncpu_target_info_set = self._get_ncpu_emc_target_info_set()
device_paths = self._get_emc_device_paths()
target_info_map = {}
for path in device_paths:
target_info_key = self._get_target_info_key(path)
if target_info_key in ncpu_target_info_set:
continue
if target_info_key not in target_info_map:
target_info_map[target_info_key] = []
target_info_map[target_info_key].append(path)
return target_info_map
def _all_related_paths_faulty(self, paths):
for path in paths:
real_path = os.path.realpath(path)
out, err = self._run_multipath(['-ll', real_path],
run_as_root=True,
check_exit_code=False)
if 'active ready' in out:
# At least one path is still working
return False
return True
def _delete_all_related_paths(self, paths):
for path in paths:
real_path = os.path.realpath(path)
device_name = os.path.basename(real_path)
device_delete = '/sys/block/%s/device/delete' % device_name
if os.path.exists(device_delete):
# Copy '1' from stdin to the device delete control file
utils.execute('cp', '/dev/stdin', device_delete,
process_input='1', run_as_root=True)
else:
print "Unable to delete %s" % real_path
def _cleanup_faulty_paths(self):
non_ncpu_target_info_map = self._get_non_ncpu_target_info_map()
for paths in non_ncpu_target_info_map.itervalues():
if self._all_related_paths_faulty(paths):
self._delete_all_related_paths(paths)
def _cleanup_faulty_dm_devices(self):
out_ll, err_ll = self._run_multipath(['-ll'],
run_as_root=True,
check_exit_code=False)
# Pattern to split the dm device contents as follows
# Each section starts with a WWN and ends with a line with
# " `-" as the prefix
#
# 3600601601bd032007c097518e96ae411 dm-2 ,
# size=1.0G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
# `-+- policy='round-robin 0' prio=0 status=active
# `- #:#:#:# - #:# active faulty running
# 36006016020d03200bb93e048f733e411 dm-0 DGC,VRAID
# size=1.0G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
# |-+- policy='round-robin 0' prio=130 status=active
# | |- 3:0:0:2 sdd 8:48 active ready running
# | `- 5:0:0:2 sdj 8:144 active ready running
# `-+- policy='round-robin 0' prio=10 status=enabled
# |- 4:0:0:2 sdg 8:96 active ready running
# `- 6:0:0:2 sdm 8:192 active ready running
dm_pat = r'([0-9a-fA-F]{30,})[^\n]+,[^\n]*\n[^,]* `-[^\n]*'
dm_m = re.compile(dm_pat)
path_pat = r'- \d+:\d+:\d+:\d+ '
path_m = re.compile(path_pat)
for m in dm_m.finditer(out_ll):
if not path_m.search(m.group(0)):
# Only #:#:#:# remain in the output, all the paths of the dm
# device should have been deleted. No need to keep the device
out_f, err_f = self._run_multipath(['-f', m.group(1)],
run_as_root=True,
check_exit_code=False)
def cleanup(self):
self._cleanup_faulty_paths()
# Make sure the following configuration is in /etc/multipath.conf
# Otherwise, there may be "map in use" failure when deleting
# dm device
#
# defaults {
# flush_on_last_del yes
# }
#
self._cleanup_faulty_dm_devices()
def _get_emc_device_paths(self):
# Find all the EMC iSCSI devices under /dev/disk/by-path
# except LUNZ and partition reference
pattern = '/dev/disk/by-path/ip-*-iscsi-iqn*com.emc*-lun-*'
device_paths = [path for path in glob.glob(pattern)
if ('lun-0' not in path and '-part' not in path)]
return device_paths
def _run_multipath(self, multipath_command, **kwargs):
check_exit_code = kwargs.pop('check_exit_code', 0)
(out, err) = utils.execute('multipath',
*multipath_command,
run_as_root=True,
check_exit_code=check_exit_code)
print ("multipath %(command)s: stdout=%(out)s stderr=%(err)s"
% {'command': multipath_command, 'out': out, 'err': err})
return out, err
if __name__ == "__main__":
if len(sys.argv) != 3 or sys.argv[1] != '--config-file':
usage()
exit(1)
out, err = utils.execute('which', 'multipath', check_exit_code=False)
if 'multipath' not in out:
print('Info: Multipath tools not installed. No cleanup need be done.')
exit(0)
multipath_flush_on_last_del = False
multipath_conf_path = "/etc/multipath.conf"
if os.path.exists(multipath_conf_path):
flush_on_last_del_yes = re.compile(r'\s*flush_on_last_del.*yes')
for line in open(multipath_conf_path, "r"):
if flush_on_last_del_yes.match(line):
multipath_flush_on_last_del = True
break
if not multipath_flush_on_last_del:
print("Warning: 'flush_on_last_del yes' is not seen in"
" /etc/multipath.conf."
" 'map in use' failure may show up during cleanup.")
CONF(sys.argv[1:])
# connect_volume and disconnect_volume in nova/virt/libvirt/volume.py
# need be adjusted to take the same 'external=True' lock for
# synchronization
@utils.synchronized('connect_volume', external=True)
def do_cleanup():
cleaner = FaultyDevicesCleaner()
cleaner.cleanup()
do_cleanup()
答案 0 :(得分：1)
https://wiki.python.org/moin/BeginnersGuide/Programmers http://www.astro.ufl.edu/~warner/prog/python.html
看起来像这个python版本3所以。去寻找第三版的教程。 尝试下载任何IDE。顺便说一句，eric5很不错。
尝试执行此文件一次。
学习缩进 和动态变量声明 不要第一次尝试游泳池跳入海洋：）