Specifically the scheduling of a job to run the temperature check & send email email alert if required, with a SystemD timer rather than a Cron job. Also removing the requirement for a separate python script. The temperature check and alert is now all done with one bash script. The script does now require installing msmtp, this does require some configuration to work with an external mail server (as did the python script in the original post); a quick google search should give you all you need; if not please comment and I’ll assist further.
Updated bash script (/home/pi/temp-check.sh):
#!/bin/bash TEMP=$(/usr/local/bin/tempered | grep -oP '(?<=/dev/hidraw1 0: temperature) [\d.]+') MAXTEMP=40 if [ $TEMP \> $MAXTEMP ]; then echo -e "Subject: $TEMP°c Temperature is to high! \r\n\r\n$TEMP°c Temperature is to high!" |msmtp --email@example.com -t firstname.lastname@example.org else echo "Temperature" $TEMP"°c, normal"; fi; unset TEMP MAXTEMP
Just set the MAXTEMP variable, to the maximum desired temperature.
Now the SystemD timer, first thing is to create the service unit (/lib/systemd/system/check-temp.service):
Being a long time user of Fedora and a frequent browser on their discourse. I quite often see posts, where users do not want to move on from a version of Fedora which they consider stable, but the version is EOL. These sort of posts are quite often followed with suggestions to use Centos rather than Fedora. Problem with this is that Centos is more of a server distro, and although its possible to install a desktop environment, it isn’t as straight forward as it is with other distros. This is why I have created a kickstart file:
Which I hope takes the hardwork out setting Gnome-workstation with Centos 8. It also includes TLP to improve battery life, is only enabled on Laptops. I looked at the way Fedora does this, but this would require changes to kernel; which is beyond the scope of this project.
Here is a script for setting up an NFS server that works within kodi for OSMC, for both kodi 18 & 19; I’ve also created created an uninstall script. This wouldn’t have been possible without the help of bmillham who is a member of the OSMC team.
Readers of my previous posts, will be aware I noticed issues with apf under systemd; further details can found here.
Further updates and improvements were reported here. On a side note I’ve never received a response to the issue I raised on rfxn’s github.
I acknowledge that life can take people away from open-source projects , so I’ve created my own fork with some extras. Not only have I made improvements over the systemd solution provided on this blog previously. The fork also includes auto update with email alert and an un-install bash script.
This is a follow up to this post. The below script is written with automated CPANEL updates in mind, but could be quite easily modified to be used with any automated updates with logs.
!/bin/bash cd /var/cpanel/updatelogs # Change to cpanel updates logs directory. VAR1=$(ls -tr up*|tail -1) # Find the latest log and set it as a variable. egrep 'Error:|error:|Another app is currently holding the yum lock|Segmentation fault' $VAR1 > /tmp/update-check # Check for errors and output to temp file if egrep 'Error:|error:|Another app is currently holding the yum lock|Segmentation fault' /tmp/update-check; then # If then to check for errors and send email alert if required. /bin/mail -s "$(echo -e "Check to see if updates work, failed\nX-Priority: 1")" < /tmp/update-check root fi unset VAR1 # Unset variable.
Cronjob should be scheduled about an hour after updates:
#!/bin/bash /usr/local/sbin/apf --start &> /tmp/check-apf if egrep 'unable to load iptables module|timed out while attempting to gain lock|could not process allow_hosts|could not process deny_hosts|apf does not appear to have rules loaded|could not verify that interface|trust rules unchanged since last refresh' /tmp/check-apf; then /usr/local/sbin/apf --stop echo "APF Aborted" exit 1 else echo "All ok" fi exit 0
From looking at /etc/apf/internals/functions.apf, the egrep should cover all possible errors. If anyone thinks I’ve missed any, please feel free to let me know.
I have confirmed results in systemd failure by changing un-trusted interface to a interface which doesn’t exist on my system.
This is an update to the blog posted here. The original scripts have an issue when updates are available, in the fact that there is an alert sent if the updates are not installed. Being as the whole point is to check whether updates work, rather than updating; this is unwanted behaviour. So the scripts have been rewritten:
#!/bin/bash /usr/bin/timeout 120 /usr/bin/yum update --assumeno &> /tmp/check-update # check for rpm database & dependency errors rm -rf /tmp/yum_save_tx* # clear yum saved transactions if egrep 'Error:|error:|Another app is currently holding the yum lock|Segmentation fault' /tmp/check-update; then # if condition checks yum output for errors and sends email if there is any /bin/mail -s "$(echo -e "Check to see if updates work, failed\nX-Priority: 1")" < /tmp/check-update root fi
#!/bin/bash /bin/timeout 120 /bin/yum update --assumeno &> /tmp/check-update # check for rpm database & dependency errors rm -rf /tmp/yum_save_tx* # clear yum saved transactions if egrep 'Error:| error:|Another app is currently holding the yum lock|Segmentation fault' /tmp/check-update; then # if condition checks yum output for errors and sends email if there is any /bin/mail -s "$(echo -e "Check to see if updates work, failed\nX-Priority: 1")" < /tmp/check-update root fi
As linux systems admin you may have multiple servers, in this case it would make sense to automate updates. But even with the best monitoring failed updates can occasionally go unnoticed, with crontab and the below script; this can be avoided.
Create the script with you choice of editor: /usr/local/sbin/ifupdateswork.sh
#!/bin/bash /bin/timeout 120 /bin/yum update --assumeno &> /tmp/check-update || /bin/mail -s "$(echo -e "Check to see if updates work, failed\nX-Priority: 1")" < /tmp/check-update root
#!/bin/bash /usr/bin/timeout 120 /usr/bin/yum update --assumeno &> /tmp/check-update || /bin/mail -s "$(echo -e "Check to see if updates work, failed\nX-Priority: 1")" < /tmp/check-update root
Lets breakdown the script before we go any further:
timeout 120 – This causes yum to automatically closes after 2 minutes, this prevents the script from causing the automatic update from failing.
yum update –assumeno – The script is only for testing updating works, not to install updates; this is what the assume no flag does.
&> /tmp/check-update – Writes (also overwrites) error and standard output to /tmp/check-update
|| /bin/mail -s “$(echo -e “Check to see if updates work, failed\nX-Priority: 1″)” < /tmp/check-update root – Email is only sent if for any reason updates would fail, subject is set to: Check to see if updates work, failed. Importance Priority 1 is set in the header of the email. Uses /tmp/check-update as the body of the email. Then sends the email to root, normally an alias would be used for root so the email is sent to the system administrator; but alias’s are not covered here.
Make the script only executable by root: $ chmod u+x /usr/local/sbin/ifupdateswork.sh
Now schedule using crontab, I suggest running this script about an hour before the automated updates so for example mine looks like this:
This Weekend I decided to challenge myself, to setting a Tranmisson Server with Arch Linux on a KVM. For those of you not aware Arch Linux is a minimalist, with a lot of self config; a rolling release with latest packages.
These are the steps I followed:
Boot The KVM with install ISO, which can be downloaded from here: https://www.archlinux.org/download/
Openvpn configuration will vary depending on the provider, essentailly though provider will provide .opvn files for each server. This needs copying to a *.vpn, for example vpn.conf. Now create /etc/pass.txt add your vpn credentials, username first line; password 2nd. Update the following in vpn.conf: