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feat(linstor): simplify get_controller_uri using ss command #121

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Merged
Wescoeur merged 2 commits into from
Feb 3, 2026
Merged

feat(linstor): simplify get_controller_uri using ss command #121

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7c1f6f0
feat(linstor): simplify `get_controller_uri` using `ss` command
Wescoeur Jan 29, 2026
4b860b0
fixes
Wescoeur Jan 29, 2026
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9 changes: 7 additions & 2 deletions drivers/linstor-manager
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,12 @@ import XenAPIPlugin
from json import JSONEncoder
from linstorjournaler import LinstorJournaler
from linstorvhdutil import LinstorVhdUtil, check_ex
from linstorvolumemanager import get_controller_uri, get_local_volume_openers, LinstorVolumeManager
from linstorvolumemanager import (
get_controller_uri,
get_local_volume_openers,
LinstorVolumeManager,
LINSTOR_SATELLITE_PORT,
)
from lock import Lock
import json
import LinstorSR
Expand All @@ -42,7 +47,7 @@ LVM_PLUGIN = 'lvm.py'
THIN_POOL = 'thin_pool'

FIREWALL_PORT_SCRIPT = '/etc/xapi.d/plugins/firewall-port'
LINSTOR_PORTS = [3366, 3370, 3376, 3377, 8076, 8077]
LINSTOR_PORTS = (LINSTOR_SATELLITE_PORT, 3370, 3376, 3377, 8076, 8077)
DRBD_PORTS = '7000:8000'

DRBD_REACTOR_CONF = '/etc/drbd-reactor.d/sm-linstor.toml'
Expand Down
94 changes: 26 additions & 68 deletions drivers/linstorvolumemanager.py
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Expand Up @@ -15,9 +15,13 @@
# along with this program. If not, see <https://www.gnu.org/licenses/>.
#

from sm_typing import Any, Dict, override
from sm_typing import (
Any,
Dict,
List,
override,
)

import errno
import json
import linstor
import os.path
Expand All @@ -38,6 +42,8 @@
DATABASE_PATH = '/var/lib/linstor'
DATABASE_MKFS = 'mkfs.ext4'

LINSTOR_SATELLITE_PORT = 3366

REG_DRBDADM_PRIMARY = re.compile("([^\\s]+)\\s+role:Primary")
REG_DRBDSETUP_IP = re.compile('[^\\s]+\\s+(.*):.*$')

Expand Down Expand Up @@ -128,73 +134,25 @@ def round_down(value, divisor):

# ==============================================================================

def get_remote_host_ip(node_name):
(ret, stdout, stderr) = util.doexec([
'drbdsetup', 'show', DATABASE_VOLUME_NAME, '--json'
])
if ret != 0:
return

def _get_controller_addresses() -> List[str]:
try:
conf = json.loads(stdout)
if not conf:
return

for connection in conf[0]['connections']:
if connection['net']['_name'] == node_name:
value = connection['path']['_remote_host']
res = REG_DRBDSETUP_IP.match(value)
if res:
return res.groups()[0]
break
except Exception:
pass


def _get_controller_uri():
PLUGIN_CMD = 'hasControllerRunning'

# Try to find controller using drbdadm.
(ret, stdout, stderr) = util.doexec([
'drbdadm', 'status', DATABASE_VOLUME_NAME
])
if ret == 0:
# If we are here, the database device exists locally.

if stdout.startswith('{} role:Primary'.format(DATABASE_VOLUME_NAME)):
# Nice case, we have the controller running on this local host.
return 'linstor://localhost'

# Try to find the host using DRBD connections.
res = REG_DRBDADM_PRIMARY.search(stdout)
if res:
node_name = res.groups()[0]
ip = get_remote_host_ip(node_name)
if ip:
return 'linstor://' + ip

# Worst case: we use many hosts in the pool (>= 4), so we can't find the
# primary using drbdadm because we don't have all connections to the
# replicated volume. `drbdadm status xcp-persistent-database` returns
# 3 connections by default.
try:
session = util.timeout_call(10, util.get_localAPI_session)
(ret, stdout, stderr) = util.doexec([
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@klmp200 klmp200 Jan 29, 2026

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You should check the return code and also that the output is indeed an IP address. It could very much be that the ss commad is missing (even if very unlikely) or that it doesn't return anything. It could also be that the output changed or many other things.

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@Wescoeur Wescoeur Jan 29, 2026

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I'm not sure it's useful to check if it's an IP address (let's say the output later shows us a hostname; we can theoretically leave it as is, all we want is a destination string). However, I'll modify the script to support IPv6 just in case...

If the program isn't there, an exception is already raised by doexec. No need to verify that.

However, you make a good point about the return check; I didn't backport that fix correctly, as I'm using a different API in my new code. :)

"/usr/sbin/ss", "-tnpH", "state", "established", f"( sport = :{LINSTOR_SATELLITE_PORT} )"
])
if ret == 0:
return [
line.split()[3].rsplit(":", 1)[0]
for line in stdout.splitlines()
]
util.SMlog(f"Unexpected code {ret}: {stderr}")
except Exception as e:
util.SMlog(f"Unable to get controller addresses: {e}")
return []

for host_ref, host_record in session.xenapi.host.get_all_records().items():
node_name = host_record['hostname']
try:
if util.strtobool(
session.xenapi.host.call_plugin(host_ref, PLUGIN, PLUGIN_CMD, {})
):
return 'linstor://' + host_record['address']
except Exception as e:
# Can throw and exception if a host is offline. So catch it.
util.SMlog('Unable to search controller on `{}`: {}'.format(
node_name, e
))
except:
# Not found, maybe we are trying to create the SR...
pass
def _get_controller_uri() -> str:
# TODO: Check that an IP address from the current pool is returned.
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@Nambrok Nambrok Feb 3, 2026

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It might not be needed to check that the controller is an existing pool. It's unlikely but a future configuration could place the controller somewhere else.

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@Wescoeur Wescoeur Feb 3, 2026

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My fear is that a host might be moved to another LINSTOR pool. I think there are some situations we just don't want to happen.

addresses = _get_controller_addresses()
return "linstor://" + addresses[0] if addresses else ""

def get_controller_uri():
retries = 0
Expand All @@ -204,7 +162,7 @@ def get_controller_uri():
return uri

retries += 1
if retries >= 10:
if retries >= 30:
break
time.sleep(1)

Expand Down