# Set up spool for me

You are helping me set up spool, a print queue for Bambu Lab 3D printers
(https://spool.spencerhubert.info). Work through it with me one step at a
time. Run what you can yourself; tell me in one line what you are about to
do before anything that needs my password (sudo) or changes my system; and
tell me plainly when a step is mine to do (a printer's own screen, a click
in an app). Keep your messages short.

## How spool fits together

- One computer is the spool. It keeps the queue, talks to the printers on
  its network, and slices with Bambu Studio installed on it. Other
  computers join it with a six-digit code.
- The spool is either the spool app (Mac, Windows or a Linux desktop; it
  starts when I sign in and keeps running with its window closed) or a
  background service on an always-on Linux computer with no screen.
- The printers must be on the same network as the spool, in LAN Only mode
  with Developer Mode on.
- Prints start only while the spool's computer is on and awake. A print
  already running always finishes on the printer.

## 1. Ask me first

- Which computer should be the spool: the one that is on most of the time,
  on the printers' network. A spare always-on Linux PC (x86_64) is best;
  otherwise the computer I use, with the app.
- Which printers I have, and whether they are on that computer's network.

## 2a. The spool is a Mac, Windows or Linux desktop computer: the app

- Fetch https://spool.spencerhubert.info/updates/downloads.json. Its
  `mac`, `windows` and `linux` keys name files under
  https://spool.spencerhubert.info/updates/.
- Mac: download the .dmg, mount it (`hdiutil attach`), copy spool.app into
  /Applications, unmount it, and open the app.
- Windows: download the .exe and run it. Windows may show "Windows
  protected your PC": I click More info, then Run anyway. When Windows asks
  whether spool may use the network, I choose Allow.
- Linux desktop: download the .AppImage, make it executable, and run it.
- The app opens a walk-through for the rest; I follow it. For slicing,
  Bambu Studio must be installed on this computer
  (https://bambulab.com/en/download/studio).
- The app updates itself.

## 2b. The spool is an always-on Linux computer: the service

- If it is not the computer you run on, ask me for its address and user and
  work over ssh.
- Install, after telling me it uses sudo:

  ```
  curl -fsSL https://spool.spencerhubert.info/install.sh | sudo sh
  ```

  This puts the program at /usr/local/bin/spool and runs it as the systemd
  service `spool` (its own user, everything kept in /var/lib/spool,
  listening on port 7850, TCP and UDP). It ends by printing a six-digit
  code: keep it for step 4. Running the same command again updates spool.
- If a firewall is on (ufw, firewalld), ask me, then allow 7850/tcp and
  7850/udp from the local network.
- Slicing needs Bambu Studio on this computer, which exists for x86_64
  only. Download its Linux AppImage from
  https://github.com/bambulab/BambuStudio/releases (the build for this
  distribution), then unpack it and move it into place:

  ```
  ./Bambu_Studio_*.AppImage --appimage-extract
  sudo mv squashfs-root /opt/bambu-studio
  ```

  spool notices it within a minute. `sudo journalctl -u spool -f` shows its
  log; if Bambu Studio cannot start, the log names what it is missing, and
  you install those libraries (ask me first).
- On an ARM computer (a Raspberry Pi) spool runs but cannot slice. Say so,
  and suggest an x86_64 computer or the app on a Mac or Windows computer
  as the spool instead.
- Status: `systemctl status spool`. Remove it: `sudo spool service
  uninstall` (the data in /var/lib/spool stays).

## 3. The printers (on each printer's own screen: I do this)

- Connect it to the same network as the spool.
- Turn on LAN Only mode, then Developer Mode, and read me its Access Code.
- In spool, the Printers page lists the printers it hears: I click Add and
  type the code. From a command line instead: `spool printers find`, then
  `spool printers add SERIAL --code CODE --name NAME`.
- Tell me the trade-off once: in LAN Only mode a printer leaves Bambu's
  cloud and the Bambu Handy app. A printer left in cloud mode can still
  print from spool through Bambu Connect
  (https://wiki.bambulab.com/en/software/bambu-connect), one click per
  print.

## 4. Other computers join the spool

- A code: in the app on the spool, Settings, This computer, Add another
  computer; on a service, `sudo spool code`. A code works once, for ten
  minutes.
- On each other computer: install the app (2a), then Settings, This
  computer, Use a spool on another computer, choose the spool, and type the
  code.
- With only a command line: `spool join CODE` finds the spool on the same
  network; `spool join http://ADDRESS:7850 CODE` reaches one elsewhere
  (through a VPN such as Tailscale). The code's output lists the spool's
  addresses.

## 5. Check that it works

- `spool find` lists the spools on this network.
- `spool printers` (on any joined computer) lists each printer and whether
  it takes commands.
- `spool help` lists everything else: parts, beds, the queue, the history.
- The `spool` command: on a Mac or Linux desktop the app puts it in
  ~/.local/bin; on Windows it is spool.exe in the app's folder, under
  resources\bin; on a service it is /usr/local/bin/spool.

## Rules for you

- Never print or repeat my printers' access codes, my passwords, or the
  tokens in /var/lib/spool or spool's settings files.
- Ask before sudo, a firewall change, or installing system packages.
- Never change a printer's settings yourself; I do that on its screen.