Essun

Essun

Essun is the mediaserver of Calafou local network. It is running Debian, the Universal Operating System. It is providing services for the people who are on the territory of Calafou. It is 8Gb ram and has 4 discs in it: 160Gb for system, 1Tb mirror discs, 3T for mediateca. You can connect here http://essun.calafou.org/

What does "Essun" mean?

Essun is one of the names of the protagonist of the Broken Earth trilogy by N. K. Jemisin. Essun belongs to a small group of people, called origenes, who have a special power to shape and redirect energy. Origenes are feared and hated by their society because of their powers, so if they are not murdered as children, they are carefully controlled, enslaved and exploited.

As the world ends, Essun is forced to join together with others. As she learns the strength of community and solidarity, she learns to use her powers without shame. And she learns that resistance is possible, even if it means causing the destruction of the world that had previously been her home.

Boot sequence: What happens when you turn on the machine?

1. BIOS
   1. Here you can press F12 to choose boot device. The default is to boot the system on the hard drive. This is useful if you want to boot a rescue or install image from a pendrive, for example.
   2. Here you can press F2 to enter the BIOS configuration, but we have to find out the BIOS password. At the moment, we have no idea what is the BIOS password! We have to search how to reset this password...
2. GRUB
   1. Here you can choose to start the system as usual, or to enter rescue mode. It is also possible to modify the kernel boot parameters. This is useful if you forgot the root password and want to reset it, for example.
3. Initramfs
   1. Here cryptsetup asks for the LUKS encryption password. The password can be typed in using a keyboard connected to essun, or through SSH if your SSH keys are installed in initramfs (in /etc/dropbear-initramfs/authorized_keys cf this. For the second option, use the unlock-essun.sh script. The actual password can be found in the calafou keyringer repository, and you can see it from your computer like this: keyringer calafou decrypt lan.essun.luks.system
4. Systemd
   1. The hard drives ("block devices") specified in /etc/crypttab are unlocked, usually using key files in /etc/luks/.
   2. The hard drives ("block devices") specified in /etc/fstab are mounted, such as /mnt/3t (a big hard drive for mediateca) and /mnt/mirror (a mirrored drive for services).
   3. Systemd manages the services, so when the computer starts, it tries to turn on the web server (apache2), etc.
5. System
   1. You can log in if your SSH key is installed in the system: ssh $USERNAME@essun.calafou.org (where $USERNAME is your username).

Services

Most of these services are only available from the local network!

Web Server

http://essun.calafou.org/

systemctl status apache2

/etc/apache2/sites-available/essun.calafou.org

The web server shows a page that explains Essum and links to the other services.

Pads

http://etherpad.calafou.org

systemctl status etherpad

/opt/etherpad-lite/settings.json

The etherpad is providing real-time multi-user editable shared persistent documents.

A few plug-ins have been installed from this framasoft list (all did not instal ...) https://github.com/YunoHost-Apps/etherpad_mypads_ynh

Streaming

http://essun.calafou.org:8000

systemctl status icecast2

/etc/icecast2/icecast.xml

Icecast2 is providing a stream ("radio") that you can play on your computer, for example with mplayer or mpv:

mplayer http://essun.calafou.org:8000

mpv http://essun.calafou.org:8000

File server

ftp://essun.calafou.org

systemctl status proftpd

/etc/proftpd/conf.d/anonftp

The file server is for uploading and downloading files. You can access it with FileZilla from popular operating systems. Or you can use a command line client such as ncftp.

ncftp ftp://essun.calafou.org

NextCloud

We could try to install it like this:

https://docs.nextcloud.com/server/17/admin_manual/installation/source_installation.html#example-installation-on-ubuntu-18-04-lts-server