Add 9router start-on-boot setup (non-root, @reboot cron, no systemd)

2026-08-11 11:30:57 +02:00
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+# 9router Start on Boot (without systemd)
+
+Make **9router** (AI router & token saver) auto-start as a **non-root user (`ardhi`)**
+when the server boots — using a `@reboot` cron job instead of a systemd unit.
+
+> Proven working on Ubuntu 26.04 (systemd) after a real reboot.
+
+---
+
+## Why not systemd / plain `9router`?
+
+- Running `9router` **without** `-t` crashes on a headless server (it waits for an
+  interactive TTY menu that doesn't exist → crash-loop with `EADDRINUSE`).
+- A plain `@reboot` cron calling `9router -t ...` directly fails because:
+  1. cron runs the job as the **cron user**, not root — so `runuser` inside is rejected
+     (`runuser: may not be used by non-root users`).
+  2. The log file gets created as **root**, so the `ardhi` process can't write to it
+     (`cannot create /home/ardhi/9router.log: Permission denied`).
+  3. The process is killed when cron's boot session tears down
+     (`Session terminated, killing shell... killed.`).
+
+This project solves all three with a tiny **wrapper script** + an **adaptive crontab**.
+
+---
+
+## Files
+
+| File | Purpose |
+|------|---------|
+| `start-9router.sh` | Detached launcher. Drops to `ardhi` if run as root, runs directly if already `ardhi`. Uses absolute paths (cron `@reboot` has a minimal `PATH`). |
+| `install.sh` | One-shot setup: installs the wrapper, fixes log ownership, and registers the `@reboot` cron as **root**. |
+| `README.md` | This file. |
+
+---
+
+## Step-by-step (manual)
+
+### 1. Install the wrapper
+```bash
+sudo cp start-9router.sh /usr/local/bin/start-9router.sh
+sudo chmod +x /usr/local/bin/start-9router.sh
+```
+
+### 2. Fix log-file ownership (so `ardhi` can write)
+```bash
+sudo touch /home/ardhi/9router.log
+sudo chown ardhi:ardhi /home/ardhi/9router.log
+sudo chmod 644 /home/ardhi/9router.log
+```
+
+### 3. Register the `@reboot` cron as ROOT
+> Must be **root's** crontab, because the wrapper uses `runuser` to drop privileges.
+```bash
+sudo crontab -l 2>/dev/null; echo "@reboot /usr/local/bin/start-9router.sh" | sudo crontab -
+```
+Verify:
+```bash
+sudo crontab -l
+# -> @reboot /usr/local/bin/start-9router.sh
+```
+
+### 4. Make sure the cron daemon is running
+```bash
+sudo systemctl enable cron
+sudo systemctl start cron
+systemctl is-active cron   # -> active
+```
+
+### 5. Disable the (broken) systemd unit if it exists
+```bash
+sudo systemctl disable 9router 2>/dev/null || true
+```
+
+### 6. Reboot and verify
+```bash
+sudo reboot
+```
+After the server is back:
+```bash
+# port should be LISTEN
+ss -ltnp | grep 20128
+
+# process should run as ardhi
+ps -eo pid,user,args | grep -E '9router -t|next-server' | grep -v grep
+
+# live check
+curl -s -o /dev/null -w "%{http_code}\n" http://127.0.0.1:20128/v1/models   # -> 200
+```
+Dashboard: **http://127.0.0.1:20128/dashboard**
+API endpoint for CLI tools: **http://127.0.0.1:20128/v1**
+
+---
+
+## Or just run the installer
+
+```bash
+sudo ./install.sh
+```
+Then reboot.
+
+---
+
+## How the wrapper works
+
+```sh
+if [ "$(id -u)" = "0" ]; then
+  # root (e.g. root's @reboot cron) -> drop to ardhi
+  setsid runuser -u ardhi -- sh -c "exec '9router' -t -n --host 127.0.0.1 --port 20128 >> LOG 2>&1 < /dev/null" &
+else
+  # already ardhi -> run directly
+  setsid 9router -t -n --host 127.0.0.1 --port 20128 >> LOG 2>&1 < /dev/null &
+fi
+```
+
+- `setsid` + `< /dev/null` → detaches the process from cron's session so it survives
+  the boot-session teardown.
+- Absolute paths (`/usr/bin/setsid`, `/usr/sbin/runuser`, `/usr/local/bin/9router`) →
+  required because cron `@reboot` runs with a minimal `PATH`.
+- The redirect happens **inside** `runuser`, so `ardhi` (not root) owns the log file.
+
+---
+
+## Notes / caveats
+
+- `@reboot` cron starts the service at boot but does **not** auto-restart it if the
+  parent `-t` process dies. For extra safety you could add a per-minute watchdog cron
+  that checks the port and re-launches the wrapper if needed.
+- Change the user (`ardhi`), port (`20128`), or bind host (`127.0.0.1`) by editing the
+  wrapper directly.
+- This setup was validated on the `9router@0.5.50` standalone build, which crashes when
+  launched without `-t` on a headless machine.
+
+---
+
+## License
+MIT — use freely.