refactor: move usb/nfs tools into new 'share' category

- rename bin/pos-usb-server -> pos-share-usb-server, pos-system-nfs-{client,server} -> pos-share-nfs-{client,server} - update # POS: headers, usage strings, INTERACTIVE_CMDS, usage() EXAMPLES, notify-scope comment - docs: new DOC/howto/share.md (USB+NFS consolidated), drop usb.md + system.md NFS sections, POS.md ### share section, HOWTO/README/AGENT_Context/README/DEV/AGENTS updates - make gen && make check green
2026-08-11 14:52:18 -04:00
parent b74dfffd0b
commit 3536f267c7
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+# How-To: `pos share`
+
+Share files and devices over the network: USB devices via the USB Redirector
+server, filesystems via NFS (SMB planned). Tools: `usb`, `nfs`.
+
+| Tool | What it does |
+|------|--------------|
+| `pos share usb server` | Control `usbsrv`: share USB devices, manage clients, callbacks, nicknames |
+| `pos share nfs server` | Manage the NFS kernel server (exports, enable/disable) |
+| `pos share nfs client` | Mount NFS shares (ephemeral or persistent systemd units) |
+
+---
+
+## `pos share usb server` — USB over network
+
+Share local USB devices over the network with the USB Redirector server.
+
+Requires `usbsrv` (the USB Redirector server binary) — a **manual** install from
+incentivespro.com, not an apt package. Point to it and it's picked up by
+`command -v usbsrv`; `install.sh` copies any precompiled `x64_bin/`/`arm64_bin/`
+binaries to `/usr/local/bin`.
+
+```bash
+pos share usb server --ls                # host devices + connected clients
+pos share usb server --ls-shared         # only shared/in-use devices
+pos share usb server --share             # interactive picker
+pos share usb server --share 0-1 3       # share device 0-1 to client 3
+pos share usb server --unshare 0-1       # stop sharing a device
+pos share usb server --auto-share on|off # auto-share new devices
+pos share usb server --callback 192.168.1.5:8080   # callback connection to a client
+pos share usb server --close-callback 192.168.1.5:8080   # close it
+pos share usb server --auto-connect on|off [client]      # remote auto-connect
+pos share usb server --disconnect 0-1     # disconnect a device from clients
+pos share usb server --disconnect all
+pos share usb server --nickname 0-1 myprinter   # friendly name (empty = remove)
+pos share usb server --timeout 0-1 300    # auto-unshare after inactivity (0=off)
+pos share usb server --port 32032         # server TCP port (restart to apply)
+pos share usb server --info               # server info
+pos share usb server --version            # server version
+```
+
+Subcommands that need input (e.g. `--share`) prompt interactively when args are
+omitted.
+
+**Recipes:**
+- **Attach a device and connect to one client, in one step:**
+  ```bash
+  pos share usb server --ls                          # note device + client IDs
+  pos share usb server --share 0-1 3
+  ```
+- **Keep the USB printer always available:** `--auto-share on` + a nickname
+  (`--nickname 0-1 printer`) so clients see a friendly name.
+- **Dedicated USB-over-network box:** set `--port` once, then clients connect
+  to that port.
+
+**Troubleshooting:**
+- `usbsrv: command not found` → the binary isn't installed; get it from
+  incentivespro.com and drop it in `x64_bin/` (or `arm64_bin/`) then re-run
+  `./install.sh`, or `sudo install -m 755 usbsrv /usr/local/bin/`.
+- Device shared but client can't see it → check the client connects to the
+  right `host:port` (see `--info`/`--port`); verify a callback/auto-connect is
+  not required for your topology.
+- Nickname/timeout don't apply → `usbsrv` persists them on the server; restart
+  the server after `--port` changes.
+
+---
+
+## `pos share nfs server` — NFS kernel server
+
+Requires `nfs-kernel-server` (in `preinstall.sh` PACKAGES). Writes to
+`/etc/exports` and reloads via `exportfs -ra`; mutating commands announce via
+`notify_send`.
+
+```bash
+pos share nfs server status                    # server active? + current exports
+pos share nfs server share /mnt/hdd            # export (generic, warns)
+pos share nfs server share /mnt/hdd '100.64.0.0/10(rw,sync,no_subtree_check)'
+pos share nfs server list                      # exportfs -v
+pos share nfs server unshare /mnt/hdd          # remove the export
+pos share nfs server reload                    # re-apply /etc/exports after hand edits
+pos share nfs server enable                    # start + boot-persist the server
+pos share nfs server disable
+```
+
+`share <path> [client]` is idempotent: an existing line for the same path is
+replaced. With no client it uses `*(rw,sync,no_subtree_check)` and **warns you
+to restrict it** — print the restricted form:
+
+- Tailscale (CGNAT): `pos share nfs server share /mnt/hdd '100.64.0.0/10(rw,sync,no_subtree_check)'`
+- WireGuard: `pos share nfs server share /mnt/hdd '10.10.0.0/24(rw,sync,no_subtree_check)'`
+- LAN: `pos share nfs server share /mnt/backups '192.168.1.0/24(ro,sync,no_subtree_check)'`
+
+**Recipes:**
+- **Share the media drive to the tailnet:**
+  ```bash
+  pos share nfs server share /mnt/hdd '100.64.0.0/10(rw,sync,no_subtree_check)'
+  pos share nfs server enable
+  ```
+- **Read-only backups to a LAN host:** use `(ro,sync,no_subtree_check)` and only
+  `enable` the server where it's needed.
+
+**Troubleshooting:**
+- "exportfs not found" → `nfs-kernel-server` isn't installed; `sudo apt install nfs-kernel-server`
+- Client sees "mount.nfs: Permission denied" → your `/etc/exports` client rule
+  doesn't cover the client's IP (check with `pos share nfs server list`); use
+  `showmount -e <server>` on the client to see what's exported
+- After editing `/etc/exports` by hand, run `pos share nfs server reload`
+- NFS is blocked → allow the ports in `pos system firewall` (or `ufw`)
+- Changes to `/etc/exports` are root-required → the tool uses `sudo`
+
+---
+
+## `pos share nfs client` — mount NFS shares
+
+Requires `nfs-common` (in `preinstall.sh` PACKAGES).
+
+```bash
+pos share nfs client mount <server:export> <local-dir>   # one-shot (mkdir -p first)
+pos share nfs client persist <server:export> <local-dir> # persistent systemd mount
+pos share nfs client list                                # active NFS mounts
+pos share nfs client unmount <local-dir>
+pos share nfs client unpersist <local-dir>               # remove the systemd unit
+```
+
+**Persistent mounts use systemd, not fstab.** `persist` writes a
+`/etc/systemd/system/<mnt-nfs-name>.mount` unit ordered after
+`network-online.target`, so the share is mounted only once all interfaces are
+up — a down/unreachable NFS server can't break boot (with fstab it could).
+`enable --now` mounts it immediately too.
+
+**Recipes:**
+- **Mount the server's media share and keep it across reboots:**
+  ```bash
+  pos share nfs client persist 100.100.100.1:/mnt/hdd /mnt/nfs/media
+  pos share nfs client list
+  ```
+- **One-off mount (no persistence):**
+  `pos share nfs client mount 10.0.0.5:/srv/data /mnt/data`
+
+**Troubleshooting:**
+- "mount.nfs not found" → `nfs-common` isn't installed; `sudo apt install nfs-common`
+- Mount hangs → check the server export (`pos share nfs server list` on the
+  server) and that the client IP is allowed; `showmount -e <server>` lists
+  exports; NFS timeouts take ~2min by default, add `timeo=50,retrans=2` via the
+  unit if needed
+- Persistent mount fails at boot when the server is off → intended: the unit
+  waits for network-online and fails cleanly, and boot continues (unlike fstab);
+  `pos share nfs client unpersist` removes it
+
+---
+
+## Related
+
+- Reference: [DOC/POS.md → share](../POS.md)