From XPUB & Lens-Based wiki

Related pages

HUB nodes


If you still need to install Tinc follow the instructions in the page Tinc

About the HUB

HUB or is a VPN wonder to gazillions XPUB things.


An (ongoing) history of sandboxes @ XPUB

IP allocation

  • 1-9: XPUB main servers
  • 10-99: shared machines used by the whole course (for admin or lessons or multi-user projects/libraries/etc)
  • 100-254: personal and/or grad projects machines
Subnet       Node                     ???
------       ----                     ---     xvm                      XPUB server, tincd overlord, destroyer of pads    skattkista               Borg Central    sandbox                  xpub3 sandbox (2019-2021)    sandbot                  xpub2 sandbox (2020-2022)    soupboat                 xpub1 sandbox (2021-2023)    etheraxis                xpub2 (2021)    breadcube                xpub1 sandbox (2022-2024)    chopchop                 xpub sandbox 2023-2025   wizardcity               Aymeric   screaming                Angeliki (student 2017-2019)   warnet                   Tash (student 2017-2019)  - offline
10.0.0.???   food                     Alice -- misconfigured, lost in ether   bootleglib               Simon (student 2018-2020)   systers                  Artemis (student 2018-2020)   watermark                Pedro (student 2018-2020)   ilinx                    Tancredi (student 2018-2020)   repeater                 Biyi (student 2018-2020)   netcare                  Rita (student 2018-2020)   cartographies            Paloma (student 2018-2020)   rushtonhosts             Steve (xpub staff), previously known as "fabulousloopdeloop"   functionalobject         Sandra (student 2019-2021)   tnh                      Tisa (student 2019-2021)   chicago                  Michael   silentserver             Louisa (2020 - 2022)   frabjousish              Euna (2020 - 2022)   namiserver               Nami (2020 - 2022)   artificalresearch        Joak (xpub and artifical research staff)   tp                       Manetta


Can I point two domains to my node?            <----- my own domain   <----- the XPUB domain + the HUB's subdomain

It depends where the RPi is located:

  • Home: both
  • XPUB studios: hub only

The reason why is not super obvious to guess if you're discovering the joys of public/private IPs. It's because of being (able or not) to reach the RPi from the outside. At home you have most likely control over the firewall in your modem/router/switch, so you can have the http port of the RPi reachable from the outside if you open a port on your modem/router/switch and have it redirected to the port on your RPi (that's what NAT does). So you can use that to point your own domain to your home IP and that's it. On top of that you have tinc that does all the magic to be reachable regardless of your network situation via http traffic tunnelling via the VPN. In the studio, you're at WdKA, you are behind the HR firewall. You cannot open ports, you can't be reached from the outside, the only option is tunneling. The only option to also have your own domain reaching the RPi in the studio would be to have the domain handled by xvm, so that when is hit, xvm (nginx really) can be configured to proxy to the VPN.

What is the advantage from using the HUB -vs- opening ports in my home router?

The HUB enables you to be super nomad, you can put the RPi anywhere, as long as it's plugged on a network that gives an IP to the RPi, and it has internet access (like your laptop or phone would), then it will immediately be avail on the HUB

Network speed: we're on uni network, it's faaaaast, you're most likely going to be limited by the RPi shitty sd card speed

Security? Hmmm... yes/no... more privacy, you don't divulge your home IP if you go through the HUB (even if the RPi is located at home)

Being part of platinum tier XPUB club :----). See

BONUS: Self-hosting is not trivial, sure you can follow the HOWTO, but it will only get you so far. So as a result, it really forces to understand basics of TCP/IP networking and HTTP traffic.

How is the list on being created?

To be visible in the list, you need to create a folder with the name of the server in /data/www/ on the XVM. Autoindex makes a links automagically.

Snippets of installation HOW TO's

(These snippets below might be moved to the other pages soon.)

Generating a ssh pubkey for the jump user

This should be done by the users themselves. This only applies to linux-like OS's. Users should be made aware what ssh keys are.

This generates a new key with a default name, so if the user already has an existing key, they should name it differently, so the existing one is not overwritten. The key should be protected by a passphrase.

ssh-keygen -t ed25519 -b 320 

Once the key is generated, we will need the public key (pubkey). Usually it would be a file called located in ~/.ssh. Just cat the file and send us the contents.
♥♥♥ Please be aware there is also a file called id_ed25519. This is the private key. Dont ever send or disclose the private key ! ♥♥♥

cat ~/.ssh/

You can also send as an attachment. If you named your key differently, it will be a file called $

Adding a jump user on XVM

There is a script called add_jumpuser. It adds a new user on XVM, that is only allowed to ssh into the remote machine. You will need:

  • Username for the user
  • IP of the machine (see below for allocation)
  • ED25519 pubkey from the user

Once you have all of this, just run on XVM (note the single quotes around the ssh pubkey):

/root/scripts/ USERNAME IP 'PUBKEY'

/root/scripts/ lol 'ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIE29EOVCl0/WjknAoEEEZSPUyCWQKNoXX2HCC123456 some1@host'

When removing the user on XVM:

  • userdel -r USERNAME
  • remove USERNAME from AllowUsers in sshd_config
  • restart sshd

How to SSH to HUB nodes

On the user's personal machine (where the public key was generated) just:

ssh -J $IP

If for any reason it doesnt work, please send us the output of:

ssh -J $IP -vvv


Here is a ssh configuration which should allow you to ssh easily from your local machine to one of the Hub nodes

using only:

ssh hub.nodename

By adding to ~/.ssh/config the following configuration, and changing with the correct details:

Host hub.nodename 
User username
Hostname  10.0.0.XXX
Identityfile ~/.ssh/id_rsa
Serveraliveinterval 30


  • nodename: is the name you would like to give this node of hub.
  • XXX: termination if node's IP
  • username: your username in the Pi and Xpub server (should be the same)
  • ~/.ssh/id_rsa location of the private keys