Start by installing the following package:
$ sudo apt install trash-cli
Then configure crontab like this:
$ crontab -e
Add a line to the crontab that looks like:
00 * * * * /usr/bin/trash-empty 7
Save the file and the crontab will update.
This means the system will very hour, on the hour, delete any files older than 7 days from the trash. The argument is the number of days in age that will be allowed. Putting 0 there trashes all files.
This is the config that worked for me.
First generate an SMTP token and a separate address for the system to use within Protonmail, otherwise this is not going to work without installing mail-bridge or something similar.
This will be special@domain.com
Configuration file is /etc/msmtprc
File owner should be root:msmtp
File permissions 0660
defaults
tls on
account default
host smtp.protonmail.ch
port 587
from special@domain.org
set_from_header on
auth on
user special@domain.org
password SMTP_TOKEN_GOES_HERE
auth plainInstall the following components:
sudo apt install msmtp msmtp-mta mailutils bsd-mailxEdit the configuration file for mail /etc/mail.rc and add the following line to it:
set mta=/usr/bin/msmtpYou may also set up aliases if you like in the file /etc/aliases where you can add lines such as:
root: master@domain.org
caroline: caroline@example.com
defaul: admin@domain.org
This is a useful hack for VPS servers to send an email as a login-notify to an email address.
You need to have a working mail subsystem on your host so that the mail command works.
This works with Ubuntu 22.04 and later versions.
Open the file /etc/pam.d/common-session and at the bottom add the following line:
session optional pam_exec.so /root/script/login-notifyCreate the following script in /root/script/login-notify
#!/bin/bash
#
# This script is run by PAM from /etc/pam.d/common-session by adding the following
# line to the bottom of the configuration file:
#
# session optional pam_exec.so /root/script/login-notify
#
# Make sure the script is executeable
#
# ichi@ichimusai.org
# Revision 1.0.0
#
[ "$PAM_TYPE" = "open_session" ] || exit 0
{
echo "User: $PAM_USER"
echo "Ruser: $PAM_RUSER"
echo "Rhost: $PAM_RHOST"
echo "Service: $PAM_SERVICE"
echo "TTY: $PAM_TTY"
echo "Date: `date +"%y%m%d-%H%M%S"`"
echo "Server: `hostname -s`"
} | mail -s "[`hostname -s`] $PAM_SERVICE login: $PAM_USER" anders@sikvall.se & This script will now be executed upon login and should send an email to the recipient with login matters.
Network manager has been working reasonably well in Ubuntu and other Debian derivatives for quite some time and then Canonical changes to netplan. This is causing some confusion and is clearly seen by many (myself included) as a step backwards.
The original configuration file residing in /etc/netplan/01-netcfg.yaml contains the following:
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
version: 2
renderer: networkd
ethernets:
enp0s31f6:
dhcp4: yesThis leads to the conclusion that reversion to network-manager with its text based interface (nmtui) etc might not be so easy but actually it is. Change the configuration file in netplan to the following:
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
# Set and change netplan renderer to NetworkManager GUI tool
network:
version: 2
renderer: NetworkManagerWhen done don’t forget to apply the changes to netplan:
$ sudo netplan applyThis takes care of the problem and now you can re-install network-manager with whatever interface you want to use and handle all your network interfaces through that instead.
This script installs some stuff I pretty much always need. It can be invoked with -d for desktop configuration in Ubuntu as well as -t for adding documentation and text utilities I use often.
Oh and it will also install zsh as your default shell including oh-my-zsh and the ’afowler’ theme.
Can easily be adapted to anything really.
# First update the system
sudo apt -y update
sudo apt -y upgrade
# General tools that is good to have for all systems
sudo apt -y install build-essential emacs git htop atop tmux byobu \
zsh borgbackup wget curl nmap net-tools traceroute mtr mosh \
irssi mc mg vim rsync rclone
# Oh my zsh
sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
# Set the good theme
sed -i 's/robbyrussell/afowler/' ~/.zshrc
while getopts hdm arg; do
case "${arg}" in
h)
echo "Usage: install [options]"
echo
echo "-d Install standard desktop tools needed."
echo "-t Text, documentation and LaTeX tools"
;;
d)
# Only if we have a desktop, othrwise skip
sudo apt -y install dconf-editor gnome-tweaks gparted flameshot
gsettings set org.gnome.shell.extensions.dash-to-dock extend-height false
gsettings set org.gnome.shell.extensions.dash-to-dock dock-position BOTTOM
;;
t)
# Multimedia stuff (with desktop)
sudo apt -y install gimp vlc inkscape texlive-all texstudio calibre sigil
;;
*)
echo "Unknown uptions, use -h for more information."
;;
esac
done
It’s quite easy, what you want to do is edit the file /etc/issue and use the special command \4 for the IPv4 address and \6 for the IPv6 address.
If you want you can also specify a specific NIC by using it like \4{enp0s3} for example.
Now everytime you boot, logout from the console etc it will shop the IP address of the server.
I grunden är det ganska enkelt att räkna på hur mycket energi som går åt när vi gör av med varmvatten. Det finns några grundbitar man behöver ha koll på.
Vattnets specifika värmekapacitivitet i flytande form är 4.2 kJ per grad och liter vatten. Nästa steg är att förstå hur mycket vatten som går åt för aktiviteten. I fallet duschning i gammal hederlig dusch som inte snålspolar kanske det går åt ca 12 liter på en minut.
Om vi duschar i 20 minuter blir det totalt en vattenmängd på
12 liter / minut gånger 20 minuter = 240 liter vatten.
Energin vi söker är alltså den energi som åtgår för att värma 240 liter vatten. Nu behöver vi räkna ut hur många grader som vi skall värma vattnet. Om vi antar att vattnet till duschen håller 40°C och vattnet som kommer in i huset håller 6°C vilket inte är helt orimliga värden behöver vattnet värmas 40 – 6 = 34 grader.
Energin för att värma vattnet blir då följande:
240 liter vatten · 36 grader · 4.2 kJ = 36 288 kJ
Joule är samma sak som wattsekunder så för att få det till kilowatttimmar delar vi helt enkelt med 3600 som är antal sekunder i en timme:
36 288 / 3600 = 10.08 kWh
Så nu vet vi att förbrukningen ligger på avrundat 10 kWh för denna duschning. Nästa steg är att beräkna vad det kostar utifrån dagens elpris. Elpriset på nordpool är elhandelspriset, dvs vad elbolaget köper elen för och varierar timme för timme. Under en viss timme kan detta vara t.ex. 460 öre/kWh.
För konsumenten tillkommer sedan alltid elöverföringsavgiften som är oftast 24 eller 30 öre beroende på var man bor, vi kan anta att det är 30 öre i det här fallet. Sedan tillkommer en energiskatt om 36 öre per kWh som staten ska ha in. På det finns också det eventuella påslag som energibolaget gör men det är oftast inte jättestort. Vi kan för formens skull tänka oss 20 öre/kWh. Till sist tillkommer moms med 25 % på hela beloppet. Vi får då:
460 + 30 + 36 = 526 öre/kWh före moms
526 · 1.25 = 657,5 öre/kWh med moms
Vi kan avrunda det till 6 kr och 58 öre för 1 kWh med detta höga priset. Kostnaden för duschningen får vi så genom att multiplicera pricet med antal förbrukade kWh som var 10 stycken:
6:58 kr/kWh · 10 kWh = 65:80 kr
Man kan ganska enkelt göra ett Excelblad över detta om man vill och leka med lite olika siffror för att se vad det blir. Kolla också din senaste elräkning kan du se vad du har för faktiskt överföringsavgift.
When logging in with mobile shell (mosh) sometimes in Ubuntu the locales will mismatch. This is easily fixed by using the following two commands:
# locale-gen "en_US.UTF-8"
# update-locale LC_ALL="en_US.UTF-8"Substitute the locale for the one you wish to use in both places and then run this. For Swedish locale use sv_SE.UTF-8 as an example.
Many things have changed from the oh so abundant 18.04 server and there are a few surprises that one needs to be aware of. One thing that has changed is that changing the MAC address no longer changes the ID when the server requests a new IP from a DHCP server.
This means that cloning a server into a new server they will start competing for the same IP address if they are on the same network so there are a few things you need to do before you deploy the new close.
Now shutdown the host, change the networking to whatever is needed (bridged most usually) and then restart the system and it should now be assigned a new IP address.
Next step is of course to change the cloes SSH keys which is done by deleting the keys in /etc/ssh by issuing the command ”rm /etc/ssh/ssh_host_*” which would delete all of them.
Then regenerate new keys from using the command ”dpkg-reconfigure openssh-server” which will generate all needed keys as if it was fresly installed.
The longer this pandemic drags on, the better the technology decisions companies make. This is entirely due to the lack of executive exposure to enterprise software ads in airports.
— Corey Quinn (@QuinnyPig) April 15, 2020