Spokes are ARM devices (e.g. OrangePi, Raspberry Pi) running Armbian that establish reverse SSH tunnels to a central hub server. The hub mounts spoke filesystems via SFTP using rclone, making files accessible across all devices without exposing them to the internet.

Quickstart

Setting up a new Hub

On a fresh Debian/Ubuntu VPS or server:

apt install git
git clone https://gut.oily.dad/justin/tinyboard
cd tinyboard
./setup.sh   # option 4 (setup new hub)

Setting up a new Spoke

On a fresh Armbian device:

Modify spoke/armbian.not_logged_in_yet accordingly, then drop it onto the SD card as /root/.not_logged_in_yet before first boot (WiFi credentials) — see Armbian Autoconfig docs
Boot, SSH in as root
Run:

apt install git
git clone https://gut.oily.dad/justin/tinyboard
cd tinyboard
./setup.sh   # option 0 (configure network)
./setup.sh   # option 1 (configure new spoke)

Onboarding a Spoke from the Hub

Once the spoke tunnel is up, run on the hub:

cd tinyboard
./setup.sh   # option 2 (onboard spoke)

Offboarding a Spoke from the Hub

cd tinyboard
./setup.sh   # option 3 (offboard spoke)

Architecture

  [ Spoke ]                        [ Hub ]
  OrangePi / RPi                   VPS / Server
  Armbian                          Any Linux

  autossh container  ──────────►  sshd (GatewayPorts)
  reverse tunnel                   port 111xx

                                   rclone SFTP mount
                                   ~/mnt/<spoke-name>/

Spokes initiate outbound SSH connections to the hub, creating reverse tunnels. The hub then uses rclone to mount each spoke's filesystem over SFTP through the tunnel. No inbound ports need to be open on the spoke.

Directory Structure

tinyboard/
├── setup.sh                  ← entry point
├── spoke/
│   ├── setup-network.sh      ← configure static IP before setup
│   ├── setup-spoke.sh        ← automated spoke setup
│   ├── compose.yaml          ← Docker Compose for autossh + syncthing
│   ├── Dockerfile            ← autossh container
│   └── armbian.not_logged_in_yet ← Armbian first-boot WiFi config template
└── hub/
    ├── setup-hub.sh          ← automated hub setup
    ├── onboard-spoke.sh      ← add a new spoke to the hub
    └── offboard-spoke.sh     ← remove a spoke from the hub

Setup Scripts

`setup.sh`

Entry point. Presents a menu: 0. Reconfigure network (static IP via netplan — SSH session will drop, reconnect)

Set up this device as a new spoke
Onboard a new spoke from the hub
Offboard a spoke from the hub
Set up this device as a new hub

`spoke/setup-network.sh`

Run as root on a new spoke before setup.sh. Configures a static IP via netplan. Supports both WiFi and wired interfaces. Automatically reverts if network connectivity is lost after applying the new config.

`spoke/setup-spoke.sh`

Run as root on a new spoke. Handles:

Package installation (apt/dnf/yum/pacman)
Docker installation
SSH server setup
Hostname configuration
SSH key generation and hub authorization
Tunnel port auto-detection on the hub
Docker image build and container start
Optional password auth disable

`hub/setup-hub.sh`

Run as root on a new hub server. Handles:

Package installation (apt/dnf/yum/pacman)
rclone installation
Hub user creation
SSH server configuration (GatewayPorts, AllowTcpForwarding)
FUSE configuration
rclone config directory setup
Optional password auth disable

`hub/onboard-spoke.sh`

Run as the hub user after a spoke connects. Handles:

SSH key generation and deployment to spoke
rclone remote configuration
Spoke registration in ~/.config/tinyboard/spokes
Per-spoke crontab entry for auto-mount on reboot

`hub/offboard-spoke.sh`

Run as the hub user to remove a spoke. Handles:

Unmounting the spoke filesystem
Removing the crontab entry
Removing the rclone remote
Optionally removing the hub SSH key
Removing from the spoke registry

Spoke Registry

The hub maintains a registry of connected spokes at ~/.config/tinyboard/spokes:

rocky  11113  /home/armbian/.ssh/armbian-rocky-202504  /home/armbian/mnt/rocky
gouda  11114  /home/armbian/.ssh/armbian-gouda-202504  /home/armbian/mnt/gouda

Each spoke gets its own mount point at ~/mnt/<spoke-name>/ and a dedicated rclone crontab entry.

Security

All communication is over SSH tunnels — no spoke ports exposed to the internet
SSH keys are used for all authentication
Scripts check and auto-fix unsafe file permissions (600/400)
Password authentication can be disabled during setup
Scripts refuse to disable password auth if no authorized keys are present (lockout prevention)
Netplan changes are verified with a 30-second connectivity check before being made permanent

Sensitive Files

Before committing, ensure the following do not contain real credentials:

spoke/armbian.not_logged_in_yet — contains WiFi SSID, password, and user passwords

Troubleshooting

`apt update` fails with beta.armbian.com error

On some Armbian images, a beta apt repository is enabled by default and may cause apt update to fail. Comment it out:

grep -r "beta.armbian" /etc/apt/sources.list /etc/apt/sources.list.d/

Open the file that contains it (usually /etc/apt/sources.list.d/armbian.sources) and comment out or remove the line referencing beta.armbian.com, then run apt update again.

Requirements

Spoke: Armbian (Debian-based), ARM device, Docker, autossh, git

Hub: Any Linux server (Debian/Ubuntu/RHEL/Arch), rclone, fuse, openssh-server

README.md

TinyBoard