connect_volume()
@lockutils.synchronized('connect_volume', 'nova-')
def connect_volume(self, connection_info, disk_info):
"""Attach the volume to instance_name."""
conf = super(LibvirtISCSIVolumeDriver,
self).connect_volume(connection_info,
disk_info)
iscsi_properties = connection_info['data']
#Multipath用来实现设备的持久化和多路径访问
libvirt_iscsi_use_multipath = CONF.libvirt_iscsi_use_multipath
if libvirt_iscsi_use_multipath:#从配置文件中判断是否支持multipath
#multipath installed, discovering other targets if available
#multipath should be configured on the nova-compute node,
#in order to fit storage vendor
out = self._run_iscsiadm_bare(['-m',
'discovery',
'-t',
'sendtargets',
'-p',
iscsi_properties['target_portal']],
check_exit_code=[0, 255])[0] \
or ""
for ip in self._get_target_portals_from_iscsiadm_output(out):
props = iscsi_properties.copy()
props['target_portal'] = ip
self._connect_to_iscsi_portal(props)
self._rescan_iscsi()
else:
self._connect_to_iscsi_portal(iscsi_properties)#连接iscsi，见下面
host_device = ("/dev/disk/by-path/ip-%s-iscsi-%s-lun-%s" %
(iscsi_properties['target_portal'],
iscsi_properties['target_iqn'],
iscsi_properties.get('target_lun', 0)))
# The /dev/disk/by-path/... node is not always present immediately
# TODO(justinsb): This retry-with-delay is a pattern, move to utils?
tries = 0
disk_dev = disk_info['dev']
while not os.path.exists(host_device):
if tries >= CONF.num_iscsi_scan_tries:
raise exception.NovaException(_("iSCSI device not found at %s")
% (host_device))
LOG.warn(_("ISCSI volume not yet found at: %(disk_dev)s. "
"Will rescan & retry. Try number: %(tries)s") %
locals())
# The rescan isn't documented as being necessary(?), but it helps
self._run_iscsiadm(iscsi_properties, ("--rescan",))#重新扫描
tries = tries + 1#重试tries次,默认3次
if not os.path.exists(host_device):
time.sleep(tries ** 2)
if tries != 0:
LOG.debug(_("Found iSCSI node %(disk_dev)s "
"(after %(tries)s rescans)") %
locals())
if libvirt_iscsi_use_multipath:
#we use the multipath device instead of the single path device
self._rescan_multipath()
multipath_device = self._get_multipath_device_name(host_device)
if multipath_device is not None:
host_device = multipath_device
conf.source_type = "block"
conf.source_path = host_device
return conf
def _connect_to_iscsi_portal(self, iscsi_properties):
# NOTE(vish): If we are on the same host as nova volume, the
# discovery makes the target so we don't need to
# run --op new. Therefore, we check to see if the
# target exists, and if we get 255 (Not Found), then
# we run --op new. This will also happen if another
# volume is using the same target.
try:
self._run_iscsiadm(iscsi_properties, ())
#执行：iscsiadm -m node -T iqn.2010-10.org.openstack:volume-c7a768b1-5b4a-49c3-80fe-a1ef007c52c1 -p 192.168.88.168:3260 execute /usr/lib/python2.7/dist-packages/nova/utils.py:208
except exception.ProcessExecutionError as exc:
# iscsiadm returns 21 for "No records found" after version 2.0-871
if exc.exit_code in [21, 255]:
self._run_iscsiadm(iscsi_properties, ('--op', 'new'))
else:
raise
if iscsi_properties.get('auth_method'):#get()返回CHAP
self._iscsiadm_update(iscsi_properties,
"node.session.auth.authmethod",
iscsi_properties['auth_method'])
#执行：iscsiadm -m node -T iqn.2010-10.org.openstack:volume-c7a768b1-5b4a-49c3-80fe-a1ef007c52c1 -p 192.168.88.168:3260 --op update -n node.session.auth.authmethod -v CHAP execute /usr/lib/python2.7/dist-packages/nova/utils.py:208
self._iscsiadm_update(iscsi_properties,
"node.session.auth.username",
iscsi_properties['auth_username'])
#执行：iscsiadm -m node -T iqn.2010-10.org.openstack:volume-c7a768b1-5b4a-49c3-80fe-a1ef007c52c1 -p 192.168.88.168:3260 --op update -n node.session.auth.username -v AREmd94wksBpTxEcJ5Yh execute /usr/lib/python2.7/dist-packages/nova/utils.py:208
self._iscsiadm_update(iscsi_properties,
"node.session.auth.password",
iscsi_properties['auth_password'])
#执行：iscsiadm -m node -T iqn.2010-10.org.openstack:volume-c7a768b1-5b4a-49c3-80fe-a1ef007c52c1 -p 192.168.88.168:3260 --op update -n node.session.auth.password -v wV4WuDvACoVyYA9Ru5tz execute /usr/lib/python2.7/dist-packages/nova/utils.py:208
#duplicate logins crash iscsiadm after load,
#so we scan active sessions to see if the node is logged in.
out = self._run_iscsiadm_bare(["-m", "session"],
run_as_root=True,
check_exit_code=[0, 1, 21])[0] or ""
#执行：iscsiadm ['-m', 'session']: stdout=
tcp: [20] 192.168.88.168:3260,1
iqn.2010-10.org.openstack:volume-14abe479-830d-4661-8047-a49414970f67
tcp: [4] 192.168.88.168:3260,1 iqn.2010-10.org.openstack:volume-993d0ed4-78b2-4c9f-a881-6aacafa173eb
stderr= _run_iscsiadm_bare /usr/lib/python2.7/dist-packages/nova/virt/libvirt/volume.py:423
portals = [{'portal': p.split(" ")[2], 'iqn': p.split(" ")[3]}
for p in out.splitlines() if p.startswith("tcp:")]
# portals=[{'iqn': 'iqn.2010-10.org.openstack:volume-14abe479-830d-4661-8047-a49414970f67', 'portal': '192.168.88.168:3260,1'}, {'iqn': 'iqn.2010-10.org.openstack:volume-993d0ed4-78b2-4c9f-a881-6aacafa173eb', 'portal': '192.168.88.168:3260,1'}]
stripped_portal = iscsi_properties['target_portal'].split(",")[0]
if len(portals) == 0 or len([s for s in portals
if stripped_portal ==
s['portal'].split(",")[0]
and
s['iqn'] ==
iscsi_properties['target_iqn']]
) == 0:
try:
self._run_iscsiadm(iscsi_properties,
("--login",),
check_exit_code=[0, 255])
#执行：iscsiadm -m node -T iqn.2010-10.org.openstack:volume-c7a768b1-5b4a-49c3-80fe-a1ef007c52c1 -p 192.168.88.168:3260 --login execute /usr/lib/python2.7/dist-packages/nova/utils.py:208
except exception.ProcessExecutionError as err:
#as this might be one of many paths,
#only set successfull logins to startup automatically
if err.exit_code in [15]:
self._iscsiadm_update(iscsi_properties,
"node.startup",
"automatic")
#执行：iscsiadm -m node -T iqn.2010-10.org.openstack:volume-c7a768b1-5b4a-49c3-80fe-a1ef007c52c1 -p 192.168.88.168:3260 --op update -n node.startup -v automatic execute /usr/lib/python2.7/dist-packages/nova/utils.py:208
return
self._iscsiadm_update(iscsi_properties,
"node.startup",
"automatic")
lua:
local access_token = ngx.var.cookie_SGAccessToken
if access_token then
ngx.header["Set-Cookie"] = "SGAccessToken="..access_token.."; path=/;Max-Age=3000"
end
