HUB

Related pages

• Tinc
• XPUB HUB Node: Sandbox
• XPUB other HUB nodes

HUB nodes

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

About the HUB

HUB or https://hub.xpub.nl is a VPN wonder to gazillions XPUB things.

To add a node to the HUB, you will need to:

• 0. Determine IP address of a new thing (see below)
• 1. Add a new thing (see below)
• 2. Ask user to give you a preferred username & a new ssh public key (see below)
• 3. Add a new jump user on the XVM (see below)
• 3. Jump user connects to his machine (see below)

FAQ

Can I point two domains to my node?

http://blabla.net/wiki/            <----- my own domain
https://hub.xpub.nl/blabla/wiki/   <----- 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 blabla.net 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 https://hub.xpub.nl.

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 https://hub.xpub.nl being created?

To be visible in the list, you need to add the link to the html page, it's a manual edit on the XVM.

Adding a new thing

See XPUB_HUB_New_Nodes

Note: invite codes can be generated by anyone with root on xvm
Note: we will only add things that can only be ssh'ed via keys, no passwd logins plz.

• On xvm:

tinc -n hub invite ${NODE_NAME}

• On ${NODE_NAME}:

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 id_ed25519.pub 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/id_ed25519.pub

You can also send id_ed25519.pub as an attachment. If you named your key differently, it will be a file called $NAME.pub

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/add_jumpuser.sh USERNAME IP 'PUBKEY'

eg.:
/root/scripts/add_jumpuser.sh lol 10.0.0.666 'ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIE29EOVCl0/WjknAoEEEZSPUyCWQKNoXX2HCC123456 some1@host'

When removing the user on XVM:

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

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             ???
------       ----             ---
10.0.0.1     xvm              XPUB server, tincd overlord, destroyer of pads
10.0.0.10    skattkista       Borg Central
10.0.0.11    sandbox          xpub2 sandbox (2019-2021) 
10.0.0.12    sandbot          xpub1 sandbox (2020-2022) 
10.0.0.100   wizardcity       Aymeric
10.0.0.101   screaming        Angeliki (student 2017-2019)
10.0.0.102   warnet           Tash (student 2017-2019)  - offline
10.0.0.???   food             Alice -- misconfigured, lost in ether
10.0.0.103   bootleglib       Simon (student 2018-2020)
10.0.0.104   systers          Artemis (student 2018-2020)
10.0.0.105   watermark        Pedro (student 2018-2020)
10.0.0.106   ilinx            Tancredi (student 2018-2020)
10.0.0.107   repeater         Biyi (student 2018-2020)
10.0.0.108   netcare          Rita (student 2018-2020)
10.0.0.109   cartographies    Paloma (student 2018-2020)
10.0.0.110   loopdeloop       Steve (xpub staff)
10.0.0.111   functionalobject Sandra (student 2019-2021)
10.0.0.112   tnh              Tisa (student 2019-2021)

How to SSH to HUB nodes

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

ssh -J xpub.nl:2501 $IP

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

ssh -J xpub.nl:2501 $IP -vvv

~/.ssh/config

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
ProxyJump username@xpub.nl:2501
Identityfile ~/.ssh/id_rsa
Serveraliveinterval 30

Where:

• 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