sonic-buildimage/files/image_config/monit/container_checker
yozhao101 2737c9681f
[container_checker] Exclude the 'always_disabled' container from expected running container list (#7217)
Signed-off-by: Yong Zhao yozhao@microsoft.com

Why I did it
Since we introduced a new value always_disabled for the state field in FEATURE table, the expected running container list
should exclude the always_diabled containers. This bug was found by nightly test and posted at here: issue. This PR fixes #7210.

How I did it
I added a logic condition to decide whether the value of state field of a container was always_disabled or not.

How to verify it
I verified this on the device str-dx010-acs-1.

Which release branch to backport (provide reason below if selected)
 201811
 201911
 202006
[ x] 202012
2021-04-02 08:05:46 -07:00

117 lines
4.5 KiB
Python
Executable File

#!/usr/bin/env python3
"""
container_checker
This script is intended to be run by Monit. It will write an alerting message into
syslog if it found containers which were expected to run but were not running. At
the same time, if some containers were unexpected to run, it also writes an alerting
syslog message. Note that if print(...) statement in this script was executed, the
string in it will be appended to Monit syslog messages.
The following is an example in Monit configuration file to show how Monit will run
this script:
check program container_checker with path "/usr/bin/container_checker"
if status != 0 for 5 times within 5 cycles then alert repeat every 1 cycles
"""
import subprocess
import sys
import swsssdk
from sonic_py_common import multi_asic
def get_command_result(command):
"""
@summary: This function will execute the command and return the resulting output.
@return: A string which contains the output of command.
"""
command_stdout = ""
try:
proc_instance = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
shell=True, universal_newlines=True)
command_stdout, command_stderr = proc_instance.communicate()
if proc_instance.returncode != 0:
print("Failed to execute the command '{}'. Return code: '{}'".format(
command, proc_instance.returncode))
sys.exit(1)
except (OSError, ValueError) as err:
print("Failed to execute the command '{}'. Error: '{}'".format(command, err))
sys.exit(2)
return command_stdout.rstrip().split("\n")
def get_expected_running_containers():
"""
@summary: This function will get the expected running containers by following the rule:
The 'state' field of container in 'FEATURE' table should not be 'disabled' or 'always_disabled'.
If the device has Multi-ASIC, this function will get container list by determining the
value of field 'has_global_scope', the number of ASICs and the value of field
'has_per_asic_scope'.
If the device has single ASIC, the container name was put into the list.
@return: A set which contains the expected running containers.
"""
config_db = swsssdk.ConfigDBConnector()
config_db.connect()
feature_table = config_db.get_table("FEATURE")
expected_running_containers = set()
for container_name in feature_table.keys():
if feature_table[container_name]["state"] not in ["disabled", "always_disabled"]:
if multi_asic.is_multi_asic():
if feature_table[container_name]["has_global_scope"] == "True":
expected_running_containers.add(container_name)
if feature_table[container_name]["has_per_asic_scope"] == "True":
num_asics = multi_asic.get_num_asics()
for asic_id in range(num_asics):
expected_running_containers.add(container_name + str(asic_id))
else:
expected_running_containers.add(container_name)
return expected_running_containers
def get_current_running_containers():
"""
@summary: This function will get the current running container list by analyzing the
output of command `docker ps`.
@return: A set which contains the current running contianers.
"""
running_containers = set()
command = "docker ps"
command_stdout = get_command_result(command)
for line in command_stdout[1:]:
running_containers.add(line.split()[-1].strip())
return running_containers
def main():
"""
@summary: This function will compare the difference between the current running containers
and the containers which were expected to run. If containers which were exepcted
to run were not running, then an alerting message will be written into syslog.
"""
expected_running_containers = get_expected_running_containers()
current_running_containers = get_current_running_containers()
not_running_containers = expected_running_containers.difference(current_running_containers)
if not_running_containers:
print("Expected containers not running: " + ", ".join(not_running_containers))
sys.exit(3)
unexpected_running_containers = current_running_containers.difference(expected_running_containers)
if unexpected_running_containers:
print("Unexpected running containers: " + ", ".join(unexpected_running_containers))
sys.exit(4)
if __name__ == "__main__":
main()