sonic-buildimage/files/scripts/write_standby.py
Lawrence Lee f317d93cb0 Merged PR 4679112: [write_standby]: Ignore non-auto interfaces
[write_standby]: Ignore non-auto interfaces

* In the event that `write_standby.py` is used to automatically switchover interfaces when linkmgrd or bgp crashes, ignore any interfaces that are not configured to auto-switch

Signed-off-by: Lawrence Lee <lawlee@microsoft.com>
2021-11-10 18:54:33 -08:00

136 lines
4.3 KiB
Python
Executable File

#!/usr/bin/env python3
import time
from sonic_py_common import logger as log
from swsscommon.swsscommon import ConfigDBConnector, DBConnector, FieldValuePairs, ProducerStateTable, SonicV2Connector
from swsscommon.swsscommon import APPL_DB
logger = log.Logger('write_standby')
REDIS_SOCK_PATH = '/var/run/redis/redis.sock'
def create_fvs(**kwargs):
return FieldValuePairs(list(kwargs.items()))
class MuxStateWriter(object):
"""
Class used to write standby mux state to APP DB
"""
def __init__(self):
self.config_db_connector = None
self.appl_db_connector = None
self.asic_db_connector = None
@property
def config_db(self):
"""
Returns config DB connector.
Initializes the connector during the first call
"""
if self.config_db_connector is None:
self.config_db_connector = ConfigDBConnector()
self.config_db_connector.connect()
return self.config_db_connector
@property
def appl_db(self):
"""
Returns the app DB connector.
Initializes the connector during the first call
"""
if self.appl_db_connector is None:
self.appl_db_connector = DBConnector(APPL_DB, REDIS_SOCK_PATH, True)
return self.appl_db_connector
@property
def asic_db(self):
"""
Returns the ASIC DB connector.
Initializes the connector during the first call
"""
if self.asic_db_connector is None:
self.asic_db_connector = SonicV2Connector()
self.asic_db_connector.connect('ASIC_DB')
return self.asic_db_connector
@property
def tunnel_name(self):
"""
Returns the name of the IP-in-IP tunnel used for Dual ToR devices
"""
return self.config_db.get_keys('TUNNEL')[0]
@property
def is_dualtor(self):
"""
Checks if script is running on a dual ToR system
"""
localhost_key = self.config_db.get_keys('DEVICE_METADATA')[0]
metadata = self.config_db.get_entry('DEVICE_METADATA', localhost_key)
return 'subtype' in metadata and 'dualtor' in metadata['subtype'].lower()
def get_auto_mux_intfs(self):
"""
Returns a list of all mux cable interfaces that are configured to auto-switch
"""
all_intfs = self.config_db.get_table('MUX_CABLE')
auto_intfs = [intf for intf, status in all_intfs.items()
if status['state'].lower() == 'auto']
return auto_intfs
def tunnel_exists(self):
"""
Checks if the IP-in-IP tunnel has been written to ASIC DB
"""
tunnel_key_pattern = 'ASIC_STATE:SAI_OBJECT_TYPE_TUNNEL:*'
return len(self.asic_db.keys('ASIC_DB', tunnel_key_pattern)) > 0
def wait_for_tunnel(self, interval=1, timeout=30):
"""
Waits until the IP-in-IP tunnel has been created
Returns:
(bool) True if the tunnel has been created
False if the timeout period is exceeded
"""
logger.log_info("Waiting for tunnel {} with timeout {} seconds".format(self.tunnel_name, timeout))
start = time.time()
curr_time = time.time()
while not self.tunnel_exists() and curr_time - start < timeout:
time.sleep(interval)
curr_time = time.time()
# If we timed out, return False else return True
return curr_time - start < timeout
def apply_mux_config(self):
"""
Writes standby mux state to APP DB for all mux interfaces
"""
if not self.is_dualtor:
# If not running on a dual ToR system, take no action
return
intfs = self.get_auto_mux_intfs()
state = 'standby'
if self.wait_for_tunnel():
logger.log_warning("Applying {} state to interfaces {}".format(state, intfs))
producer_state_table = ProducerStateTable(self.appl_db, 'MUX_CABLE_TABLE')
fvs = create_fvs(state=state)
for intf in intfs:
producer_state_table.set(intf, fvs)
else:
logger.log_error("Timed out waiting for tunnel {}, mux state will not be written".format(self.tunnel_name))
if __name__ == '__main__':
mux_writer = MuxStateWriter()
mux_writer.apply_mux_config()