# Netboot Operations Guide

This document covers day-to-day operations for the netboot K3s cluster system.

## Quick Reference

```bash
# Build new image (15-30 min, requires sudo)
cd /home/lindahl/git/netboot
sudo ./build-image.sh
make deploy

# Rebuild initramfs only (faster, ~2 min)
sudo ./rebuild-initramfs.sh
make deploy

# SSH to a node
ssh root@192.168.100.51

# Check node storage
ssh root@192.168.100.51 "lsblk && df -h /var/lib/containerd /var/lib/longhorn"
```

## Architecture Overview

```
┌─────────────────┐     HTTP (8800)      ┌──────────────────┐
│  Phoenix NAS    │◄────────────────────►│   K3s Nodes      │
│  192.168.100.1  │                      │  192.168.100.5x  │
├─────────────────┤                      ├──────────────────┤
│ /srv/netboot/   │                      │ RAM (overlay)    │
│   http/         │                      │   └─ / (root)    │
│     vmlinuz     │                      │ NVMe (persistent)│
│     initrd-netboot.img                 │   ├─ containerd  │
│     filesystem.squashfs                │   └─ longhorn    │
│     boot.ipxe   │                      └──────────────────┘
└─────────────────┘
```

**Boot sequence:**
1. Node PXE boots → loads iPXE
2. iPXE fetches `boot.ipxe` from phoenix
3. Downloads kernel + initramfs
4. Initramfs downloads squashfs root over HTTP
5. Mounts squashfs read-only with tmpfs overlay
6. `setup-node-storage.service` partitions/mounts local NVMe
7. System starts, K3s joins cluster

## Building Images

### Full Build

Builds everything from scratch: debootstrap, packages, initramfs, squashfs.

```bash
cd /home/lindahl/git/netboot
sudo ./build-image.sh
make deploy
```

**Time:** 15-30 minutes
**When to use:** Package changes, kernel updates, major configuration changes

### Initramfs-Only Rebuild

Faster rebuild when only changing boot/network logic.

```bash
sudo ./rebuild-initramfs.sh
make deploy
```

**Time:** ~2 minutes
**When to use:** Changes to `initramfs/` scripts or hooks

### Verify Build

Check that all components are present and valid:

```bash
./verify-image.sh
```

## Secret Management

Secrets are encrypted with [sops](https://github.com/getsops/sops) using age encryption. The age key lives on phoenix.

### Encrypted Files

| File | Contents |
|------|----------|
| `secrets/netboot.sops.yaml` | Root password hash for console login |

### Viewing Secrets

```bash
# From any machine with SSH access to phoenix
cat secrets/netboot.sops.yaml | ssh phoenix "sops -d --input-type yaml --output-type yaml /dev/stdin"
```

### Updating Root Password

1. Generate new password hash:
   ```bash
   ssh phoenix "echo 'newpassword' | openssl passwd -6 -stdin"
   ```

2. Update the encrypted file:
   ```bash
   ssh phoenix "cd /path/to/netboot && sops secrets/netboot.sops.yaml"
   # Edit root_password_hash value, save
   ```

   Or recreate entirely:
   ```bash
   NEW_HASH=$(ssh phoenix "echo 'newpassword' | openssl passwd -6 -stdin")
   ssh phoenix "echo 'root_password_hash: \"$NEW_HASH\"' | sops --input-type yaml --output-type yaml -e --age age1gausnystsln7fpenw7arw7x79xe22z697jnauj38npy0usayqqxqc7td2y /dev/stdin" > secrets/netboot.sops.yaml
   ```

3. Rebuild and deploy:
   ```bash
   sudo ./build-image.sh
   make deploy
   ```

4. Reboot nodes to pick up new password

### Adding New Secrets

Edit `.sops.yaml` to add new file patterns, then create encrypted files on phoenix:

```bash
ssh phoenix "sops secrets/newfile.sops.yaml"
```

## Node Storage Setup

Local NVMe is automatically partitioned on first boot by `setup-node-storage.service`.

### Partition Layout

| Partition | Size | Label | Mount Point | Purpose |
|-----------|------|-------|-------------|---------|
| nvme0n1p1 | 75GB | containerd | /var/lib/containerd | Container images |
| nvme0n1p2 | Remaining | longhorn | /var/lib/longhorn | Distributed storage |

### Automatic Behavior

| Drive State | Action |
|-------------|--------|
| No partition table | Auto-format (no prompt) |
| Has our labels (containerd/longhorn) | Mount silently |
| Has unknown partitions | Prompt on tty1, 120s timeout, skip if no response |

### Manual Intervention

If a node has an unknown drive and you want to format it:

1. Connect to physical console (tty1)
2. Reboot the node
3. Press ENTER when prompted (within 120 seconds)
4. Wait 5 seconds (abort window)
5. Drive is formatted and mounted

### Checking Storage Status

```bash
# On node
journalctl -u setup-node-storage
cat /var/lib/containerd/.netboot-storage  # marker file with metadata
lsblk /dev/nvme0n1
df -h /var/lib/containerd /var/lib/longhorn
```

## SSH Access

### Authorized Keys

Keys are baked into the image at build time. Current keys:

| Key | Source |
|-----|--------|
| `ssh-ed25519 AAAAC3...y1J` | lindahl@lindahl-Legion-5-Pro-16ACH6H |
| `ssh-ed25519 AAAA...0tX` | lindahl@phoenix.home |

To add/remove keys, edit `build-image.sh` around line 164-167.

### Console Access

Root password is set for physical console login only. SSH remains pubkey-only.

```bash
# Physical console or IPMI
login: root
Password: <from secrets/netboot.sops.yaml>
```

## Troubleshooting

### Node Won't Boot

1. Check phoenix HTTP server:
   ```bash
   ssh phoenix "curl -I http://localhost:8800/boot.ipxe"
   ssh phoenix "ls -lh /srv/netboot/http/"
   ```

2. Check nginx is running:
   ```bash
   ssh phoenix "systemctl status nginx"
   ```

3. Verify image integrity:
   ```bash
   ./verify-image.sh
   ```

### Node Boots But No Network

1. Check if initramfs has network driver:
   ```bash
   lsinitramfs http/initrd-netboot.img | grep -E "r8169|r8125"
   ```

2. Check kernel cmdline includes `ip=dhcp`:
   ```bash
   cat http/boot.ipxe
   ```

### Storage Not Mounting

1. Check service status:
   ```bash
   ssh root@node "systemctl status setup-node-storage"
   ssh root@node "journalctl -u setup-node-storage"
   ```

2. Check if NVMe exists:
   ```bash
   ssh root@node "lsblk"
   ```

3. Check labels:
   ```bash
   ssh root@node "blkid -L containerd && blkid -L longhorn"
   ```

### Overlay Filling Up

The root overlay is only 2GB. If it fills:

```bash
# Check what's using space
ssh root@node "du -sh /var/* | sort -h"

# Temporary files should go to NVMe or tmpfs mounts
# /tmp, /var/tmp, /var/log are separate tmpfs
```

## File Reference

| File | Purpose |
|------|---------|
| `build-image.sh` | Main build script |
| `rebuild-initramfs.sh` | Quick initramfs rebuild |
| `verify-image.sh` | Validate built image |
| `Makefile` | Build/deploy automation |
| `initramfs/` | Custom initramfs config for mkinitramfs |
| `initramfs/scripts/netboot` | HTTP root download and overlay mount |
| `files/setup-node-storage` | NVMe partitioning script |
| `files/setup-node-storage.service` | Systemd unit for storage setup |
| `secrets/netboot.sops.yaml` | Encrypted root password |
| `.sops.yaml` | Sops encryption config |
| `http/boot.ipxe` | iPXE boot configuration |

## Network Configuration

### IP Address Layout

| Range | Purpose |
|-------|---------|
| .1 | phoenix (gateway, DHCP, HTTP) |
| .2-.19 | Reserved (future infrastructure) |
| .20-.29 | Infrastructure devices |
| .50-.59 | Static K3s nodes |
| .60-.100 | Dynamic DHCP pool |

### Static Assignments

| Host | IP | MAC | Role |
|------|-----|-----|------|
| phoenix | 192.168.100.1 | - | NAS, HTTP server, DHCP |
| usw-flex-2 | 192.168.100.21 | 94:2a:6f:4c:fc:72 | Managed switch |
| k3s-node-01 | 192.168.100.51 | 78:55:36:04:e7:c8 | K3s worker |
| k3s-node-02 | 192.168.100.52 | 78:55:36:04:e7:1d | K3s worker |

HTTP server: `http://192.168.100.1:8800/`

### DHCP Reservations

Static IP assignments are configured in `/etc/dnsmasq.d/pxe-netboot.conf` on phoenix:

```
dhcp-range=192.168.100.60,192.168.100.100,12h

# Static DHCP reservations for K3s nodes
dhcp-host=78:55:36:04:e7:c8,192.168.100.51,k3s-node-01
dhcp-host=78:55:36:04:e7:1d,192.168.100.52,k3s-node-02

# Infrastructure
dhcp-host=94:2a:6f:4c:fc:72,192.168.100.21,usw-flex-2
```

To add a new node:

1. Boot the node once to get its MAC (check leases):
   ```bash
   ssh phoenix "cat /var/lib/misc/dnsmasq.leases"
   ```

2. Add reservation:
   ```bash
   ssh phoenix "sudo tee -a /etc/dnsmasq.d/pxe-netboot.conf << EOF
   dhcp-host=XX:XX:XX:XX:XX:XX,192.168.100.5X,k3s-node-0X
   EOF"
   ```

3. Restart dnsmasq:
   ```bash
   ssh phoenix "sudo systemctl restart dnsmasq"
   ```

To change the boot server IP, edit `http/boot.ipxe` and `initramfs/scripts/netboot`.