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Mini Shell
Mini Shell
# -*- coding: utf-8 -*-
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2021 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
from __future__ import absolute_import
import subprocess
from typing import Optional, Tuple, Dict
from clwpos import gettext as _
from clcommon.utils import ExternalProgramFailed, run_command
from clwpos.cl_wpos_exceptions import WposError
class DeadRedisPurgeAttempt(WposError):
"""
Happens when somebody tries to purge
redis instance which is not runnning
"""
def __init__(self):
super().__init__(message=_(
"Unable to purge cache because cache database is not running. "
"Enable at least one optimization feature to start cache database instance."))
class PurgeFailedError(WposError):
"""
Happens when redis is not able to purge cached data for some reason.
"""
def __init__(self, std_out: str, std_err: str):
super().__init__(
message=_('Unable to purge cache. \n'
'Database backend returned error of command "%(command)s" execution. '
'Try again a bit later or contact your system administrator for help.'),
details='stdout: \n<i>%(stdout)s</i>\n'
'stderr: \n<i>%(stderr)s</i>\n',
context={
"command": 'purge',
"stdout": std_out or 'empty',
"stderr": std_err or 'empty',
})
class RedisLibUser(object):
def __init__(self, socket_path: str,
redis_cli_path: str = "/opt/alt/redis/bin/redis-cli") -> None:
self.socket_path = socket_path
self.redis_cli_path = redis_cli_path
def get_redis_shell_command(self, redis_command):
return [
self.redis_cli_path,
"-s",
self.socket_path,
] + redis_command.split(" ")
def run_redis_command(self, command: str) -> Tuple[int, str, str]:
redis_command = self.get_redis_shell_command(command)
try:
returncode, std_out, std_err = run_command(
redis_command, return_full_output=True
)
except (subprocess.CalledProcessError, ExternalProgramFailed) as error:
raise WposError(
message=_("Error during %(command)s command execution: \n%(error)s"),
context={"command": " ".join(redis_command), "error": str(error)},
)
return returncode, std_out, std_err
def purge_redis(self) -> Dict:
"""
Clean entire redis cache for user.
"""
if not self.is_redis_alive():
raise DeadRedisPurgeAttempt()
purge_command = "flushall async"
returncode, std_out, std_err = self.run_redis_command(purge_command)
# Output of Redis FLUSHALL command should be: "OK"
if returncode != 0 or "ok" not in std_out.lower():
raise PurgeFailedError(std_out, std_err)
return {
"used_memory": self.get_redis_used_memory()
}
def is_redis_alive(self) -> bool:
"""
Check if user's redis is alive.
"""
returncode, std_out, _ = self.run_redis_command("ping")
return returncode == 0 and "pong" in std_out.lower()
def is_redis_empty(self) -> bool:
"""
Check if user's redis is empty.
Example (redis is empty):
# Keyspace
Example (redis is NOT empty):
# Keyspace
db0:keys=2,expires=0,avg_ttl=0
"""
returncode, std_out, _ = self.run_redis_command("info keyspace")
return returncode == 0 and len(std_out.strip().split("\n")) <= 1
def get_redis_used_memory(self) -> Optional[str]:
"""
Return amount of memmory used by user's redis instance
in human readable format (kb or mb).
If redis status is offline, 'used_memory_value' value is null.
'info memory' command output:
# Memory
used_memory:369616
used_memory_human:360.95K
...
"""
_, std_out, _ = self.run_redis_command("info memory")
for line in std_out.split("\n"):
if not line.startswith("used_memory_human"):
continue
_, used_memory_value = line.split(":")
return used_memory_value if used_memory_value != "null" else None
Zerion Mini Shell 1.0