Raw Diamonds

The Raspberry Pi originated with the idea of teaching children to program, and sales skyrocketed, with more than 18 million units sold to date. A new model with improved hardware, the Raspberry Pi 3 Model B+, was recently released. The applications range from baby monitors to the 300-node Raspberry Pi cluster [1] at the Free University of Bozen-Bolzano, Italy, and the 750-node HPC testbed [2] at Los Alamos National Laboratory, New Mexico. SUSE even supplies its Enterprise Server 12 for the single-board computer (SBC) [3]. In this article, I reveal my personal list of the best projects.

NextCloudPi

Hard-working developer Nacho Parker from the Nextcloud environment maintains a NextCloudPi (NCPi) image for the Raspberry Pi that connects the standard Raspbian distribution with the Nextcloud storage software (Figure 1). As he told Linux Pro Magazine, one other developer besides him works on the distribution code. The continuously updated image is based on Raspbian 9 and is adapted to the current Nextcloud version 13.0.1. NCPi [4] is available as an ARM image or x86 Docker container.

Figure 1: NextCloudPi connects the Raspberry Pi with the Nextcloud file-sharing software.

The code for NCPi is available from GitHub [5], where instructions for using the build script for the Raspbian image, an x86 image, and a Docker ARM hard-float (armhf) image are provided. In addition to the prebuilt Raspberry Pi image, Docker images for the Raspberry Pi, the x86 platform, and hardware based on armhf can be found there. The server scores up to 1,000 NCPi downloads per day.

NCPi includes its own setup tool and supports automatic security updates, Let's Encrypt, and Fail2Ban, as well as Redis, APCu PHP cache, and PHP Zend OPcache. Apps for calendars, contacts, tasks, and notes are preinstalled. Lately, NCPi supports the ZRAM kernel module, which serves as a swap or generic RAM disk.

If you are looking for an operating system that is always up to date and already contains a meaningfully preconfigured Nextcloud installation, you will certainly find it with NCPi. Support is provided by a specially set up Nextcloud subforum [6].

According to Parker, developers are currently focusing on improving the usability of the web interface, extending the functions for the Docker version, and building images for additional SBCs.

Pi-hole

The Pi-hole "DNS sinkhole" protects all the devices on your home network from banners and trackers. It is based on the lightweight web servers Lighttpd and Dnsmasq. Jacob Salmela has been working on the project since 2015.

From a technical point of view, Pi-hole internally manages a list of approximately 120,000 domain names that deliver advertisements or trackers to users. Because Pi-hole acts as a DNS server on the local network, it effectively blocks unwanted domains. A website requested on the network cannot even load the advertisements placed on it.

Install Pi-hole on the Raspberry Pi with the command:

curl -sSL https://install.pi-hole.net | bash

The configuration that follows only prompts the user for some basic data about the network. You can add further block lists through a web interface. Afterward, you need to specify the Raspberry Pi as the DNS server for your network. The easiest way to do this is via the router, for which you can find detailed instructions online [7].

Because Pi-hole blocks most advertising at the DNS level, no resources need to be turned off on the LAN. Pi-hole is particularly useful for in-app advertising on smartphones or apps on smart TVs. It can also serve as a DHCP server and is compatible with DNSCrypt. The project can be found on GitHub [8].

motionEyeOS

One common application for the Raspberry Pi is camera surveillance of rooms or outdoor areas. The Motion project [9] provides this service, be it to observe your pet or the hatching of the offspring in a bird's nest, or to monitor machine operations. Your Raspberry Pi can handle these tasks in combination with Motion. However, setting up such a solution is not trivial and requires experience in using the command line.

This is where motionEyeOS (Figure 2) comes in [10]. Under development since 2014, the system is based on BuildRoot [11] and uses Motion as the back end and motionEye as the front end.

Figure 2: Adding a camera to motionEyeOS.

The operating system can handle one or more cameras. Multiple Raspberry Pis can be interconnected via a hub or server and configured together. In addition to surveillance, an IP camera can serve as a webcam. motionEye can be used on a number of other SBCs or an x86 desktop under Linux. The wiki offers many detailed instructions [12].

According to the developer, Calin Crisan, the project has about 10,000 users. In the near future, he will be looking to provide an API for the project that users can use to build their own extensions and derived projects.