Jack Moore

Email: jack(at)jmoore53.com
Project Updates

Installing check_mk for monitoring

23 Dec 2021 » ansible, automation, configuration, logging

CheckMK provides for an easy enough way to configure monitoring and alerting. Right now I am using a docker container.

CheckMK Docker Container

docker container run -dit -p 8080:5000 --tmpfs /opt/omd/sites/cmk/tmp:uid=1000,gid=1000 -v/omd/sites --name monitoring -v/etc/localtime:/etc/localtime:ro --restart always checkmk/check-mk-raw:2.0.0-latest

The official documentation can be found here for the docker deploy. After the deploy is complete, running docker logs will then show the password for the gui.

Fixing Inode and Space Issues with the log server

Check_MK and the host will sometimes run into some issues with inode and disk space.

I still have yet to figure out logrotate, but basically where the issue lies is in /var/log/remotelogs. There are too many files that are being created and not cleaned causing the issues.

Removing all the folders (moving them if necessary) will solve this issue temporarily.

Matrix Alerts

Because I ran checkmk within a container, I had to add python from within the container with the following:


sudo apt update
sudo apt install software-properties-common
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt update
sudo apt install python3.8
python --version

Then I had to copy the following file to matrix.py located at ~/local/share/check_mk/notifications/matrix.py - In the container the directory may not be at ~/local, but rather somewhere in the application directory.

#!/usr/bin/env python3

# Check_mk notifications sender to Matrix.
#
# Copyright(c) 2019, Stanislav N. aka pztrn.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files(the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject
# to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
# OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import json
import os
import random
import string
import sys
import requests

MATRIXHOST = os.environ["NOTIFY_PARAMETER_1"]
MATRIXTOKEN = os.environ["NOTIFY_PARAMETER_2"]
MATRIXROOM = os.environ["NOTIFY_PARAMETER_3"]

data = {
    "TS": os.environ["NOTIFY_SHORTDATETIME"],

    # Host related info.
    "HOST": os.environ["NOTIFY_HOSTNAME"],
    "HOSTADDR": os.environ["NOTIFY_HOSTADDRESS"],
    "HOSTSTATE": os.environ["NOTIFY_HOSTSTATE"],
    "HOSTSTATEPREVIOUS": os.environ["NOTIFY_LASTHOSTSTATE"],
    "HOSTSTATECOUNT": os.environ["NOTIFY_HOSTNOTIFICATIONNUMBER"],
    "HOSTOUTPUT": os.environ["NOTIFY_HOSTOUTPUT"],

    # Service related info.
    "SERVICE": os.environ["NOTIFY_SERVICEDESC"],
    "SERVICESTATE": os.environ["NOTIFY_SERVICESTATE"],
    "SERVICESTATEPREVIOUS": os.environ["NOTIFY_LASTSERVICESTATE"],
    "SERVICESTATECOUNT": os.environ["NOTIFY_SERVICENOTIFICATIONNUMBER"],
    "SERVICEOUTPUT": os.environ["NOTIFY_SERVICEOUTPUT"]
}

servicemessage = '''Service <b>{SERVICE}</b> at <b>{HOST}</b> ({HOSTADDR}) | TS: {TS} | STATE: <b>{SERVICESTATE}</b>
<br>{SERVICEOUTPUT}<br>'''

hostmessage = '''Host <b>{HOST}</b> ({HOSTADDR}) | TS: {TS} | STATE: <b>{HOSTSTATE}</b>
<br>{HOSTOUTPUT}<br>'''

message = ""

print(data)

# Checking host status first.
if (data["HOSTSTATE"] != data["HOSTSTATEPREVIOUS"] or data["HOSTSTATECOUNT"] != "0"):
    message = hostmessage.format(**data)

# Check service state.
# We're replacing it because host state notifications flows in separately
# from service state notifications and we have no need in host state here.
if (data["SERVICESTATE"] != data["SERVICESTATEPREVIOUS"] or data["SERVICESTATECOUNT"] != "0") and (data["SERVICE"] != "$SERVICEDESC$"):
    message = servicemessage.format(**data)

# Data we will send to Matrix Homeserver.
matrixDataDict = {
    "msgtype": "m.text",
    "body": message,
    "format": "org.matrix.custom.html",
    "formatted_body": message,
}
matrixData = json.dumps(matrixDataDict)
matrixData = matrixData.encode("utf-8")

# Random transaction ID for Matrix Homeserver.
txnId = ''.join(random.SystemRandom().choice(
    string.ascii_uppercase + string.digits) for _ in range(16))
# Authorization headers and etc.
matrixHeaders = {"Authorization": "Bearer " + MATRIXTOKEN,
                 "Content-Type": "application/json", "Content-Length": str(len(matrixData))}
# Request.
req = requests.put(url=MATRIXHOST + "/_matrix/client/r0/rooms/" + MATRIXROOM +
                             "/send/m.room.message/" + txnId, data=matrixData, headers=matrixHeaders)


© Jack Moore