Quite often web applications need to send email notifications. For example Moodle needs to notify students and teachers about various events. Installing a mail server is not so easy because it needs also some DNS and other configurations, in order to do it properly. Otherwise the mails that are sent will end up being classified as spam and most probably will not reach the recipient. This article describes how to build such a mail server.
I have an old MacBook Pro with Linux dual boot. Maybe because I have tinkered with the partition table, it failed to do a clean upgrade on its own, living me with a broken macos system that would not boot. Recovery and internet recovery (Cmd+R) failed as well. Luckily I managed to find a way to install it back again, while preserving the Linux installation.
GnuPG (GNU Privacy Guard) is a complete and free implementation of the OpenPGP standard. It allows you to encrypt and sign your data and communications. GnuPG has scads of options which make it a flexible and powerful encryption framework. However this also makes it extremely complicated to get started with, and that quite reasonably puts people off.EasyGnuPG is a wrapper script that tries to simplify the process of using GnuPG. In order to simplify things, it is opinionated about the "right" way to use GnuPG.
Moodle is a well known and mature LMS (Learning Management System) that is used widely throughout the world. There are several ways for installing and maintaining Moodle and we will see some of them. Then we will present some shell scripts that facilitate the installation and maintenance of Moodle. We will see that they are simpler and more cost effective than the other available solutions.
Often it is desirable to install several web pages or web applications in the same server, in order to minimize costs. However this is not so easy and presents some challenges. We will discuss several ways of trying to accomplish it, and argue that using Docker is the most efficient and the most easy one. We will also see some use cases of applications that can be installed with Docker, which actually make use of some custom shell scripts that I have developed.
The Secure SHell (ssh) is normally used for remote login to another system. However it is a flexible and powerful tool that can be used for many other interesting things as well. One of them is port forwarding (also known as ssh tunneling) between the client and the server machine. Althought there are lots of tutorials out there, I always find it a bit confusing how to use it properly. So, I am writting yet another tutorial about ssh tunneling, based on use cases and examples, hoping to make its usage clear to myself and to the others.
There is a command-line twitter client that can be used to send tweets to a certain account from terminal. Combining it with cron and other linux tools I have built a twitter-bot that sends proverbs periodically to twitter (https://twitter.com/l10n_sq). I will describe here how I did it.
In public computers (e.g. in schools, libraries, universities, etc.) it is useful to have a frozen guest account. This means that the content of the account is temporary and is erased immediately after logout or reboot. This is important because it reverts automatically all the default settings, no matter how much the users mess with them, therefore minimising the need for maintenance. It is also important for the safety of the users, because it ensures that no open accounts or passwords are left behind.
LTSP allows computers of a LAN to boot through network from a single server. One of the benefits of this is for example to cut down the administration and maintenance time of a classroom of computers (instead of installing, configuring and updating each of them we do it only once).
Docker is an open platform for developing, shipping, and running applications.