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Automatic updates on Ubuntu and Debian

First install the package

~$ apt-get install unattended-upgrades apt-listchanges


Create file /etc/apt/apt.conf.d/20auto-upgrades

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";


In /etc/apt/apt.conf.d/50unattended-upgrades add

# for ubuntu
"${distro_id} stable";
"${distro_id} ${distro_codename}-security";
# for debian
Unattended-Upgrade::MinimalSteps "true";
Unattended-Upgrade::Mail "";
Unattended-Upgrade::MailOnlyOnError "false";
Unattended-Upgrade::Automatic-Reboot "false";

Generate a QR code to use on your android mobile to connect to your wireless network

Install qrencode

~$ apt-get install qrencode


To generate the QR code

~$ qrencode -t svg -o example.svg 'WIFI:T:WPA;S:My Network;P:My Password;;'


Make sure all the backslashes, single-quotes, double-quotes, semicolons, colons, dots, commas in your SSID and Password get escaped with a \

Poodle-Attack - Disable SSLv3 in apache, postfix, dovecot


In your site configuration add

SSLProtocol all -SSLv2 -SSLv3 +TLSv1 +TLSv1.2 +TLSv1.1
SSLHonorCipherOrder On



In your file

smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3



In your 10-ssl.conf file

ssl_protocols = !SSLv2 !SSLv3
# SSL ciphers to use
#ssl_cipher_list = ALL:!LOW:!SSLv2:!EXP:!aNULL


To test if SSLv3 is disabled you can run

openssl s_client -connect -ssl3


Install dependency when compiling from source

When you install some software from source it is always a pain to get the packages which are needed for dependency. Auto-apt is a package which solves this issue.

~$ apt-get install auto-apt
~$ auto-apt update
~$ auto-apt update-local
~$ auto-apt -y -x run ./configure .....

auto-apt will check during the configure run which packages are needed and installs them automatically.

Use perl to compare version numbers

~$ perl -wle 'print 1 unless "7.0.23-1" gt "7.0.25-2"'

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