# Migration Guide: Hard-coded IPs → Guest Agent Discovery

**Date:** 2025-11-27  
**Purpose:** Guide for updating remaining scripts to use guest-agent IP discovery

## Quick Reference

### Before
```bash
VMS=(
    "100 cloudflare-tunnel 192.168.1.60"
    "101 k3s-master 192.168.1.188"
)

read -r vmid name ip <<< "$vm_spec"
ssh "${VM_USER}@${ip}" ...
```

### After
```bash
source "$PROJECT_ROOT/scripts/lib/proxmox_vm_helpers.sh"

VMS=(
    "100 cloudflare-tunnel"
    "101 k3s-master"
)

read -r vmid name <<< "$vm_spec"
ip="$(get_vm_ip_or_warn "$vmid" "$name" || true)"
[[ -z "$ip" ]] && continue
ssh "${VM_USER}@${ip}" ...
```

## Step-by-Step Migration

### Step 1: Add Helper Library

At the top of your script (after loading .env):

```bash
# Import helper library
if [ -f "$PROJECT_ROOT/scripts/lib/proxmox_vm_helpers.sh" ]; then
    source "$PROJECT_ROOT/scripts/lib/proxmox_vm_helpers.sh"
else
    log_error "Helper library not found. Run this script on Proxmox host or via SSH."
    exit 1
fi
```

### Step 2: Update VM Array

Remove IPs, keep only VMID and NAME:

```bash
# Before
VMS=(
    "100 cloudflare-tunnel 192.168.1.60"
)

# After
VMS=(
    "100 cloudflare-tunnel"
)
```

### Step 3: Update Loop Logic

```bash
# Before
for vm_spec in "${VMS[@]}"; do
    read -r vmid name ip <<< "$vm_spec"
    ssh "${VM_USER}@${ip}" ...
done

# After
for vm_spec in "${VMS[@]}"; do
    read -r vmid name <<< "$vm_spec"
    
    # Ensure guest agent is enabled
    ensure_guest_agent_enabled "$vmid" || true
    
    # Get IP from guest agent
    ip="$(get_vm_ip_or_warn "$vmid" "$name" || true)"
    if [[ -z "$ip" ]]; then
        log_warn "Skipping VM $vmid ($name) – no IP from guest agent"
        continue
    fi
    
    ssh "${VM_USER}@${ip}" ...
done
```

### Step 4: For Bootstrap Scripts (QGA Installation)

Use fallback IPs:

```bash
# Fallback IPs for bootstrap
declare -A FALLBACK_IPS=(
  ["100"]="192.168.1.60"
  ["101"]="192.168.1.188"
)

for vm_spec in "${VMS[@]}"; do
    read -r vmid name <<< "$vm_spec"
    
    # Try guest agent first, fallback to hardcoded
    ip="$(get_vm_ip_or_fallback "$vmid" "$name" "${FALLBACK_IPS[$vmid]:-}" || true)"
    [[ -z "$ip" ]] && continue
    
    # Install QGA using discovered/fallback IP
    ssh "${VM_USER}@${ip}" "sudo apt install -y qemu-guest-agent"
done
```

## Scripts Already Updated

✅ `scripts/deploy/configure-vm-services.sh`  
✅ `scripts/deploy/add-ssh-keys-to-vms.sh`  
✅ `scripts/deploy/verify-cloud-init.sh`  
✅ `scripts/infrastructure/install-qemu-guest-agent.sh`  
✅ `scripts/fix/fix-vm-ssh-via-console.sh`  
✅ `scripts/ops/ssh-test-all.sh` (example)

## Scripts Needing Update

📋 High Priority:
- `scripts/troubleshooting/diagnose-vm-issues.sh`
- `scripts/troubleshooting/test-all-access-paths.sh`
- `scripts/deploy/deploy-vms-via-api.sh` (IPs needed for creation, discovery after)

📋 Medium Priority:
- `scripts/vm-management/**/*.sh` (many scripts)
- `scripts/infrastructure/**/*.sh` (various)

📋 Low Priority:
- Documentation scripts
- One-time setup scripts

## Testing

After updating a script:

1. **Ensure jq is installed on Proxmox host:**
   ```bash
   ssh root@192.168.1.206 "apt update && apt install -y jq"
   ```

2. **Ensure QEMU Guest Agent is installed in VMs:**
   ```bash
   ./scripts/infrastructure/install-qemu-guest-agent.sh
   ```

3. **Test the script:**
   ```bash
   ./scripts/your-updated-script.sh
   ```

4. **Verify IP discovery:**
   - Script should discover IPs automatically
   - No hard-coded IPs in output
   - Graceful handling if guest agent unavailable

## Common Patterns

### Pattern 1: Simple SSH Loop
```bash
for vm_spec in "${VMS[@]}"; do
    read -r vmid name <<< "$vm_spec"
    ip="$(get_vm_ip_or_warn "$vmid" "$name" || true)"
    [[ -z "$ip" ]] && continue
    ssh "${VM_USER}@${ip}" "command"
done
```

### Pattern 2: Collect IPs First
```bash
declare -A VM_IPS
for vm_spec in "${VMS[@]}"; do
    read -r vmid name <<< "$vm_spec"
    ip="$(get_vm_ip_or_warn "$vmid" "$name" || true)"
    [[ -n "$ip" ]] && VM_IPS["$vmid"]="$ip"
done

# Use collected IPs
if [[ -n "${VM_IPS[100]:-}" ]]; then
    do_something "${VM_IPS[100]}"
fi
```

### Pattern 3: Bootstrap with Fallback
```bash
declare -A FALLBACK_IPS=(
  ["100"]="192.168.1.60"
)

for vm_spec in "${VMS[@]}"; do
    read -r vmid name <<< "$vm_spec"
    ip="$(get_vm_ip_or_fallback "$vmid" "$name" "${FALLBACK_IPS[$vmid]:-}" || true)"
    [[ -z "$ip" ]] && continue
    # Use IP for bootstrap
done
```

## Benefits After Migration

1. ✅ No IP maintenance in scripts
2. ✅ Works with DHCP, dynamic IPs
3. ✅ Single source of truth (guest agent)
4. ✅ Easier to add new VMs
5. ✅ Better error handling

---

**Next:** Update remaining scripts following this pattern. Start with high-priority scripts.