How to monitor available package updates
Use Monibot to monitor available software updates for your servers.
Keeping your server up-to-date
If you are running a server, it is important that you keep it updated.
For Linux, that means you have to run your package manager's update
mechanism often enough so that your server stays up-to-date and secure.
In this article, we'll use the apt system found on
Debian-based distributions (Debian, Ubuntu, Linux-Mint, etc.) for
illustration purposes.
To show available package updates, you would normally run the following commands:
root:~# apt update root:~# apt list --upgradable Listing... Done linux-image-amd64/oldoldstable,oldoldstable 4.19+105+deb10u21 amd64 [upgradable from: 4.19+105+deb10u20] N: There are 2 additional versions. Please use the '-a' switch to see them.
The apt update command is used to update the
local package database.
The apt list --upgradable command then lists all package
that can be upgraded now.
In the example above, one update (a new Linux image) is available.
You, as a server administrator, can now decide if you want to
install the new packages or not.
To keep your server up-to-date, you have to check regularly, for example once a day, for available package updates. This process is time-consuming, so let's automate it with Monibot.
Create a Monibot metric
Let's create a metric that monitors the number of upgradable packages.
- Log into Monibot and click the 'Metrics' menu.
- Click the 'New Metric' button. Enter a name for the metric, e.g. 'Package Updates'. You can chose any name here, it's used only for display.
- As metric type, select 'Gauge'. A gauge is a numeric value that can go up and down, which is what we want for the number of upgradable packages.
- Click 'Save'. Monibot creates the metric and assigns a unique id to it, the metric id. You will need that later.
Send metric values to Monibot
To send values for the 'Package Updates' metric, you can use the curl command
or our moni command line tool, which we'll use in the following.
As root, create a 'packages.sh' script with the following content:
#!/bin/sh # update local package db apt update # initialize api key and metric id - please replace with your values MONIBOT_API_KEY=0000000000 METRIC_ID=7777777777 # get number of updates and store it in PACKAGES variable PACKAGES=$(apt list --upgradable | grep upgradable | wc -l) # use moni 'set' command to upload value to Monibot moni -apiKey $MONIBOT_API_KEY set $METRIC_ID $PACKAGES
This script will get the number of upgradable apt packages
and send it to the 'Package Updates' metric.
Now put the script in your root's crontab, so that it is executed automatically, for example once per hour.
root:~# crontab -l # m h dom mon dow command 0 * * * * /root/packages.sh
From now on, Monibot will show the number of available package updates as a metric. When the metric shows a value of 1 or more, you know you'll have to log in to your server and start an update.
