airlock 0.1.0

[0.1.0] — 2026-07-09

First public tag. Airlock is a network card reader appliance for the
Raspberry Pi 4: plug in USB media, expose it over SMB and a small web UI,
manage it (browse / upload / format / relabel) from any device on your LAN.

Added — daemon

• Netlink udev subscription that auto-mounts USB block devices under
  /mnt/airlock/<name> with per-filesystem mount options for FAT32,
  exFAT, NTFS (kernel ntfs3), ext2/3/4, HFS+ (read-only), and ISO9660.
• Multi-partition drives: each partition becomes its own share; hybrid-ISO
  layouts are handled by skipping partitions when the parent disk is
  already mounted as a filesystem.
• Read-only detection: media flagged read-only in /sys/class/block/*/ro
  (write-protect switch, iso9660, etc.) is mounted RO and refuses writes
  via HTTP / SMB.
• Safety guards against ever exposing the Pi's own boot media: udev rule
  matches only USB sd* devices, and every mount pass cross-checks
  /proc/self/mountinfo for prior mounts.
• Dynamic Samba shares: airlockd regenerates a single include file at
  /etc/samba/smb.conf.d/airlock.conf on each drive change and calls
  smbcontrol reload-config — no smbd restart.
• Startup state recovery: on daemon restart, stale /mnt/airlock/*
  mounts are force-unmounted and udevadm trigger --action=add --subsystem-match=block re-fires ADD events for currently attached
  devices.
• Owner lookup: the guest Samba force user is resolved at start from
  UID 1000, so the same binary works on both pi-gen-built images
  (airlock) and generic Raspberry Pi OS installs (pi, emdzej, …).
• Physical GPIO controls: button on GPIO 17 (BCM) triggers a global
  eject; LED on GPIO 27 reflects state (off / solid / fast-blink busy)
  via a small state machine. Fails soft when no chip / no wiring.
• Avahi advertisement of _smb._tcp, _http._tcp and
  _device-info._tcp — the last one carries model=TimeCapsule6,106
  so macOS Finder renders the host as a network drive instead of a
  generic computer.
• sync()-on-shutdown; no automatic unmount on shutdown so a systemd
  restart never yanks a user's data.

Added — HTTP UI (http://<host>.local/)

• Mounts tab: current shares with per-share Eject, clickable
  smb://… links, and a Copy button that puts the platform-appropriate
  form on the clipboard (\\host\share on Windows, smb://… elsewhere).
• Devices tab: enumerates every USB block device via lsblk -bJ,
  showing model, vendor, serial, size, partition-table type, and every
  partition (mounted or not). Per-device Eject / Format… actions,
  per-partition Rename (volume label).
• File browser at /drives/{share}/: breadcrumbs, sort dirs-first,
  download links, delete + rename with type-to-confirm dialogs, mkdir.
  Upload accepts individual files, whole folders (webkitdirectory),
  and drag-drop of files or folders — folder tree is preserved on the
  target. One HTTP request per file with per-file progress; the progress
  card has an expandable Details panel showing status of each item.
• Format modal (Devices tab) with:
  • filesystem picker (FAT32 / exFAT / NTFS / ext4) auto-selected by
    device size (FAT32 <32 GB, exFAT ≥32 GB);
  • new-label field with per-FS length limits;
  • type-to-confirm safety (matches an existing label, or the literal
    word FORMAT if the drive is unlabeled);
  • SSE-streamed progress (unmount → wipe → partition → rescan → mkfs → done);
  • device quarantine while the operation runs, so the daemon does not
    auto-mount the fresh partition mid-mkfs.
• Volume relabel per partition (Devices tab): unmounts, runs the
  FS-specific tool (fatlabel, exfatlabel, ntfslabel, e2label),
  triggers udev to remount under the new label.
• Live polling: pages fetch state every 3 s and only touch the DOM when
  the underlying JSON differs — no flashing reloads, scroll/hover state
  preserved.
• Version + GitHub link in the footer of every page.

Added — packaging & tooling

• pi-gen custom stage (image/pi-gen/stage-airlock/) producing an
  arm64 Bookworm image with a read-only root (overlayroot=tmpfs) and
  all daemon dependencies preinstalled.
• Installer for existing Raspberry Pi OS installs (scripts/install.sh):
  idempotent, downloads a matching arm64 binary from GitHub Releases,
  drops the systemd unit / udev rule / Samba / Avahi configuration,
  backs up any existing smb.conf before overwriting, enables and
  starts everything. Environment overrides for version, custom URL,
  local binary path, and install prefix.
• Manual install guide (docs/install.md) covering prerequisites,
  quick-install one-liner, step-by-step manual install, macOS/Linux/
  Windows client instructions, GPIO wiring diagram, uninstall, and
  troubleshooting.
• GitHub Actions CI (.github/workflows/ci.yml): go vet, go test -race, host build, cross-compile arm64, and shellcheck on the
  installer.
• GitHub Actions Release (.github/workflows/release.yml): triggered
  by any <major>.<minor>.<patch> tag (no v prefix required),
  publishes airlockd-<tag>-linux-arm64.tar.gz + sha256, an offline
  install bundle, and the raw install.sh on the GitHub Release.

Known limitations

• Not tested on Raspberry Pi 5 (would need ChipName config override
  for GPIO — Pi 5 uses gpiochip4).
• Read-only root is defined in the pi-gen stage but the full image
  build (make image) has not yet been round-tripped on a fresh Pi.
• Corporate networks with mDNS filtering or 802.1X-controlled Ethernet
  are intentionally out of scope. Home / small-office LANs only.
• Multi-partition creation, live resize, and encrypted volumes
  (LUKS / BitLocker) are out of scope by design.

Full Changelog: https://github.com/emdzej/airlock/commits/0.1.0