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Improve code quality of check_redis_cluster.py
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Meik Milevczik committed Sep 23, 2020
1 parent 0f65f9a commit 7c312e3
Showing 1 changed file with 33 additions and 10 deletions.
43 changes: 33 additions & 10 deletions src/check_redis_cluster.py
Original file line number Diff line number Diff line change
Expand Up @@ -32,24 +32,28 @@
from argparse import ArgumentParser
from sys import exit


def main():
"""Main entrypoint for script"""

args = get_parser().parse_args()

master_addr, master_state, cluster_state_master, failed_master = _get_cluster_status(
args.master_port, args.password)
slave_addr, slave_state, cluster_state_slave, failed_slave = _get_cluster_status(
args.slave_port, args.password)
master_addr, master_state, cluster_state_master, failed_master = (
_get_cluster_status(args.master_port, args.password)
)
slave_addr, slave_state, cluster_state_slave, failed_slave = (
_get_cluster_status(args.slave_port, args.password)
)
if master_state != 'unknown' and slave_state != 'unknown':
failed_hosts = failed_master + failed_slave
if cluster_state_master != 'ok' and cluster_state_slave != 'ok':
print('CRITICAL - cluster is broken')
code = 2
elif len(failed_master + failed_slave) > 0:
elif failed_hosts:
print('WARNING - cluster status is degraded')
for host in failed_master + failed_slave:
code = 1
for host in failed_hosts:
print('{} is in a failed state'.format(host))
code = 1
else:
print('OK - cluster status is OK')
print('{} - {}'.format(master_addr, master_state))
Expand Down Expand Up @@ -80,15 +84,15 @@ def get_parser():
'--master-port',
action='store',
dest='master_port',
type=int,
type=str,
default=7000,
help='redis port of the master instance',
)
parser.add_argument(
'--slave-port',
action='store',
dest='slave_port',
type=int,
type=str,
default=7001,
help='redis port of the slave instance',
)
Expand All @@ -109,14 +113,33 @@ def _get_cluster_status(port, password):
The status of the local instances will be checked
"""

"""The output from redis-cli cluser nodes has the following format:
6 lines where each line is a space seperated list with the following data:
<hex_string> (hash of the node)
<ip>:7001@17001 (ip:port@remote port)
slave,fail (myself,)?(master|slave)(,fail)?
<hex_string> (remote node hash)
<number> (performance data)
<number> (performance data)
<number> (number of connected clients)
connected (fixed string)
The string ",fail" is optional. It will only exists on failed hosts
"""
try:
role = subprocess.check_output(
'redis-cli -p {0} -a {1} cluster nodes'.format(
port, password), shell=True).decode().split()
# Find keyword myself in the output
state_index = [i for i, s in enumerate(role) if 'myself' in s][0]
failed_hosts = [role[i-1] for i, s in enumerate(role) if 'fail' in s and str(port) in role[i-1]]
# Remove "myself," from the string. It will be either master or slave
role_state = role[state_index].replace('myself,', '')
# Get ip:port information which is one to the left of mysql, string
role_addr = role[state_index - 1]
# Get ip:port of the node that uses the current port and
# is in status "fail".
failed_hosts = [role[i-1] for i, s in enumerate(role)
if 'fail' in s and port in role[i-1]]

cluster_state = subprocess.check_output(
'redis-cli -p {0} -a {1} cluster info'.format(
Expand Down

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