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skynet-webportal/setup-scripts/health-checker.py

167 lines
6.0 KiB
Python
Executable File

#!/usr/bin/env python3
import asyncio
import io
import json
import os
import re
import sys
import traceback
from datetime import datetime, timedelta
import discord
import pytz.reference
import requests
from bot_utils import setup, send_msg
from tzlocal import get_localzone
"""
health-checker reads the /health-check endpoint of the portal and dispatches
messages to a Discord channel.
"""
# Get the number of hours to look back in the logs or use 1 as default.
CHECK_HOURS = 1
if len(sys.argv) > 3:
CHECK_HOURS = int(sys.argv[3])
# Discord messages have a limit on their length set at 2000 bytes. We use
# a lower limit in order to leave some space for additional message text.
DISCORD_MAX_MESSAGE_LENGTH = 1900
GB = 1 << 30 # 1 GiB in bytes
# We are going to issue Discord warnings if the free space on a server falls
# under this threshold.
FREE_DISK_SPACE_THRESHOLD = 50 * GB
bot_token = setup()
client = discord.Client()
# exit_after kills the script if it hasn't exited on its own after `delay` seconds
async def exit_after(delay):
await asyncio.sleep(delay)
os._exit(0)
@client.event
async def on_ready():
await run_checks()
asyncio.create_task(exit_after(3))
async def run_checks():
print("Running Skynet portal health checks")
try:
await check_load_average()
await check_disk()
await check_health()
except:
trace = traceback.format_exc()
print("[DEBUG] run_checks() failed.")
if len(trace) < DISCORD_MAX_MESSAGE_LENGTH:
await send_msg(client, "```\n{}\n```".format(trace), force_notify=False)
else:
await send_msg(client, "Failed to run the portal health checks!",
file=discord.File(io.BytesIO(trace.encode()), filename="failed_checks.log"),
force_notify=True)
# check_load_average monitors the system's load average value and issues a
# warning message if it exceeds 10.
async def check_load_average():
uptime_string = os.popen("uptime").read().strip()
if sys.platform == "Darwin":
pattern = "^.*load averages: \d*\.\d* \d*\.\d* (\d*\.\d*)$"
else:
pattern = "^.*load average: \d*\.\d*, \d*\.\d*, (\d*\.\d*)$"
load_av = re.match(pattern, uptime_string).group(1)
if float(load_av) > 10:
await send_msg(client, "High system load detected: `uptime: {}`".format(uptime_string), force_notify=True)
# check_disk checks the amount of free space on the /home partition and issues
# a warning message if it's under FREE_DISK_SPACE_THRESHOLD GB.
async def check_disk():
# We check free disk space in 1024 byte units, so it's easy to convert.
df = os.popen("df --block-size=1024").read().strip()
volumes = {}
for line in df.split("\n")[1:]:
fields = list(filter(None, line.split(" ")))
# -1 is "mounted on", 3 is "available space" in KiB which we want in bytes
volumes[fields[-1]] = fields[3] * 1024
# List of mount point, longest to shortest. We'll use that to find the best
# fit for the volume we want to check.
mount_points = sorted(volumes.keys(), key=len, reverse=True)
wd = os.popen("pwd").read().strip()
vol = ""
for mp in mount_points:
if wd.startswith(mp):
vol = mp
break
if vol == "":
msg = "Failed to check free disk space! Didn't find a suitable mount point to check.\ndf output:\n{}".format(df)
await send_msg(client, msg)
return
if int(volumes[vol]) < FREE_DISK_SPACE_THRESHOLD:
free_space_gb = "{:.2f}".format(int(volumes[vol]) / GB)
await send_msg(client, "WARNING! Low disk space: {}GiB".format(free_space_gb), force_notify=True)
return
# check_health checks /health-check endpoint and reports recent issues
async def check_health():
print("\nChecking portal health status...")
try:
res = requests.get("http://localhost/health-check", verify=False)
except:
trace = traceback.format_exc()
print("[DEBUG] check_health() failed.")
if len(trace) < DISCORD_MAX_MESSAGE_LENGTH:
await send_msg(client, "```\n{}\n```".format(trace), force_notify=False)
else:
await send_msg(client, "Failed to run the checks!",
file=discord.File(io.BytesIO(trace.encode()), filename="failed_checks.log"),
force_notify=True)
return
# Check the health records.
passed_checks = 0
failed_checks = 0
failed_critical = 0
failed_records = []
time_limit_unaware = datetime.now() - timedelta(hours=CHECK_HOURS) # local time
time_limit = time_limit_unaware.astimezone(get_localzone()) # time with time zone
for rec in res.json():
time_unaware = datetime.strptime(rec['date'], '%Y-%m-%dT%H:%M:%S.%fZ') # time in UTC
time = pytz.utc.localize(time_unaware) # time with time zone
if time < time_limit:
continue
bad = False
for check in rec['checks']:
if check['up'] == False:
bad = True
failed_checks += 1
if check['critical']:
failed_critical += 1
if bad:
# We append the entire record, so we can get the full context.
failed_records.append(rec)
passed_checks += 1
checks = passed_checks + failed_checks
if len(failed_records) > 0:
message = "Found {}/{} failed checks ({} critical) over the last {} hours!".format(failed_checks, checks,
failed_critical, CHECK_HOURS)
file = discord.File(io.BytesIO(json.dumps(failed_records, indent=2).encode()), filename="failed_checks.log")
notifyTeam = failed_critical > 0
await send_msg(client, message, file=file, force_notify=notifyTeam)
return
# Send an informational heartbeat if all checks passed.
await send_msg(client, "Health checks passed: {}/{}\n".format(passed_checks, checks))
client.run(bot_token)