# ttyforce

Text user interface for installing [Town OS](https://town-os.github.io). Presented during disk provisioning, it handles network configuration and disk setup through an nmtui-style interface.

## Usage

```bash
# Detect hardware and print the manifest to stdout
ttyforce detect

# Detect hardware, save manifest to a file
ttyforce detect -o hardware.toml

# Print manifest from an existing hardware file (no auto-detection)
ttyforce detect -i fixtures/hardware/ethernet_4disk_same.toml

# Run a scripted fixture scenario and print the resulting operations
ttyforce detect --fixture fixtures/scenarios/full_install_ethernet_4disk.toml

# Detect real hardware, run the TUI with a mock executor,
# and print the operations that would be performed (dry run)
ttyforce output

# Same dry run, but load hardware from a file
ttyforce output -i fixtures/hardware/ethernet_1disk.toml

# Save the dry-run operations manifest to a file
ttyforce output -o operations.toml

# Detect hardware and launch the real installer
ttyforce run

# Launch in initrd mode (syscalls, no systemd dbus)
ttyforce initrd

# Initrd mode with custom /etc target for config files
ttyforce initrd --etc-prefix /mnt/root

# Initrd mode on a specific TTY device
ttyforce initrd --tty /dev/tty1

# Initrd mode with SSH key import for system users
ttyforce initrd --ssh-user root,erikh

# Launch the real installer with hardware from a file (mock executor)
ttyforce run -i fixtures/hardware/ethernet_1disk.toml

# Run as getty replacement (system status + login screen)
ttyforce getty

# Getty on a specific TTY
ttyforce getty --tty /dev/tty1

# Getty with custom etc prefix (passed through on reconfigure)
ttyforce getty --etc-prefix /mnt/root

# Getty with initrd reconfigure mode
ttyforce getty --initrd

# Getty on console TTY in initrd mode
ttyforce getty --console --initrd

# Getty with SSH key import for system users
ttyforce getty --ssh-user root,erikh

# Getty in mock mode (no real operations)
ttyforce getty --mock --quit

# Getty with sledgehammer wipe boot entry
ttyforce getty --sledgehammer-grub-entry 2
```

### Subcommands

| Subcommand | Description |
|---|---|
| `detect` | Detect hardware and print the hardware manifest. With `--fixture`, runs a scripted scenario and prints the resulting operations manifest instead. |
| `output` | Detect real hardware (or load via `-i`), run the full TUI with a mock executor so no real changes are made, then print the operations that would have been performed. |
| `run` | Detect hardware (or load via `-i`) and launch the real installer using systemd. Uses the real executor when auto-detecting, mock executor when loading from file. |
| `initrd` | Run installer in initrd mode using syscalls (no systemd dbus). Supports `--etc-prefix` for custom config file location, `--tty` for TTY device selection, and `--ssh-user` for SSH key import. |
| `getty` | Run as a getty replacement (login screen with system status). Shows machine info, service health, and mDNS URL. At startup, shows live journal output until all services are active, then switches to the status panel. Pressing `.` clears the screen, displays `/etc/issue`, and execs into `/bin/login`. Supports `--etc-prefix`, `--tty`, `--console`, `--quit` (enable `[q]` to quit and log out), `--initrd` (use initrd mode for reconfigure), `--ssh-user` (SSH key import users), `--mock` (dry-run mode), and `--sledgehammer-grub-entry` (GRUB entry for sledgehammer wipe boot). |

### Global flags

| Flag | Description |
|---|---|
| `-i, --input <FILE>` | Load hardware from a manifest file instead of auto-detecting. |
| `-o, --output <FILE>` | Write output to a file instead of stdout. |

## How it works

### Network

The installer prioritizes getting online with minimal user interaction:

1. If a wired connection with link+carrier is already up, it selects it and advances directly to disk setup — no probing or DHCP reconfiguration
2. If ethernet has link but no carrier, it brings the interface up step by step (enable, check link, DHCP, IP check, connectivity checks)
3. If ethernet is dead or absent, it falls back to wifi
4. Wifi presents a scannable network list with signal strength and security info
5. Supports WPA2/WPA3 password entry, QR code configuration, and WPS push-button connection

### Disks

Disks are automatically grouped by transport type (SATA, NVMe, etc.) and similar size (within 10 GB). Drives with identical make and model are always grouped together; groups on the same transport with similar capacity are merged as "Mixed &lt;transport&gt; drives". The filesystem is always Btrfs. RAID options are presented based on disk count:

- **1 disk** — single drive
- **2 disks** — RAID1 (Btrfs mirror)
- **3+ disks** — RAID5 (Btrfs striped with parity)

The installation target mount point defaults to `/town-os`.

### Command output pane

The bottom half of the TUI shows a live command output log. Every shell command and syscall operation is logged with its arguments and result. Commands are color-coded: yellow for the command line, green for success, red for errors.

### Final screen

After installation completes (or is aborted), the final screen offers three choices:

- **Reboot** — restart the machine into the new system
- **Exit** — return to the shell
- **Power Off** — shut down

### Executor modes

Two executor backends are available:

- **Systemd** (default) — Uses systemd dbus interfaces (networkd, resolved, logind) with sysfs/command fallbacks. Suitable for full systemd environments.
- **Initrd** (`--initrd`) — Uses syscalls and sysfs directly where possible, with minimal external tool dependencies. After a successful install, network configuration (networkd units and wpa_supplicant configs) is persisted to `<mount_point>/@etc/` (overridable via `--etc-prefix`) so the installed system boots with working networking.

  **Safe system access (no unsafe code):**
  - Interface up/down — `ip link set`
  - IP address check — `ip -4 -o addr show`
  - Link/carrier check — sysfs `/sys/class/net/<iface>/carrier`
  - Route check — `/proc/net/route`
  - Internet check — `ping`
  - DNS resolution — UDP socket to nameserver from `/etc/resolv.conf`
  - Mount/unmount — `mount(2)` / `umount2(2)` via nix crate
  - Reboot — `reboot(2)` via nix crate

  **Required external tools in initrd:**
  - `ip` — interface up/down and IP address queries
  - `ping` — internet reachability check
  - `dhcpcd` — DHCP client
  - `wpa_supplicant` — WPA authentication (CLI mode, no dbus)
  - `wpa_cli` — WPS push-button connection and status polling
  - `iw` — wifi scanning (fallback: `iwlist`)
  - `rfkill` — unblock wifi radio before detection (best-effort)
  - `modprobe` — load wifi kernel modules in initrd (best-effort)
  - `parted` — disk partitioning
  - `mkfs.btrfs` — btrfs filesystem creation
  - `btrfs` — subvolume management
  - `install.sh` — custom install script (optional)
  - `pkill` — cleanup of dhcpcd/wpa_supplicant processes
  - `curl` — fetch SSH public keys from GitHub

### SSH key import

During installation, after confirming disk setup, ttyforce prompts for GitHub usernames to import SSH keys from. Enter usernames one at a time; press Enter on a blank line or type `q` to finish and proceed with the install. Keys are fetched from `https://github.com/<username>.keys` via `curl` and written to `/root/.ssh/authorized_keys` on the live system. A copy is also persisted to `<etc_prefix>/ssh/authorized_keys.d/github` for boot-time restoration.

### Hardware detection

Detection uses systemd dbus interfaces with sysfs/command fallbacks. Negative results from networkd are never trusted on their own — the installer always falls through to direct system checks (sysfs carrier, `ip addr show`, `ip route`, etc.):

- **Network interfaces** — systemd-networkd (`org.freedesktop.network1`) for link/carrier state, wpa_supplicant dbus for wifi scanning, sysfs and `ip` command as fallbacks
- **Disks** — UDisks2 (`org.freedesktop.UDisks2`) for block device enumeration and drive metadata
- **DNS** — systemd-resolved (`org.freedesktop.resolve1`) for name resolution, with `dig`/`getent` fallback

## Testing

Tests *do not* touch the host and do not require root. They use containers, so a VM is also a good place to test.

```bash
# Unit + fixture + scenario + playbook + CLI tests (includes lint)
make test

# Integration tests in a container (requires podman, uses sudo if needed)
make test-integration
```

### Fixtures

Hardware manifests in `fixtures/hardware/` define simulated hardware configurations:

- `ethernet_4disk_same` — ethernet + 4 identical disks
- `ethernet_1disk` — ethernet + 1 disk
- `wifi_1disk` — wifi only + 1 disk
- `wifi_crowded_1disk` — crowded wifi neighborhood
- `wifi_ethernet_*` — both interfaces present
- `wifi_dead_ethernet_*` — dead ethernet, wifi available
- `mixed_drives_*` — workstation/server/homelab with mixed drive vendors

Use with `detect` or `output` via `-i`:

```bash
ttyforce detect -i fixtures/hardware/ethernet_4disk_same.toml
ttyforce output -i fixtures/hardware/ethernet_4disk_same.toml
```

### Scenarios

Scripted test cases in `fixtures/scenarios/` feed inputs and mock responses to the state machine non-interactively:

```bash
ttyforce detect --fixture fixtures/scenarios/full_install_ethernet_4disk.toml
```

### Playbooks

Playbooks in `fixtures/playbooks/` extend scenarios with assertions — expected screen transitions, operation sequences, and final state. These are verified by `cargo test --test playbook_tests`.

## Town OS integration

ttyforce is designed as part of the [Town OS install system](https://gitea.com/town-os/install). It replaces the storage provisioning scripts (`make-btrfs.sh`) with an interactive TUI.

## License

MIT
