# 📦 Provisioning — boot, installation, server management

## Network boot (PXE / iPXE)

### PXE boot flow

```
1. Server power-on → PXE ROM in NIC / UEFI
2. DHCP Broadcast → DHCP server offers IP + next-server (TFTP) + boot file
3. TFTP downloads pxelinux.0 (BIOS) / bootx64.efi (UEFI)
4. Loads configuration (pxelinux.cfg/default or MAC/IP-based)
5. Downloads kernel + initrd via TFTP/HTTP (iPXE)
6. Kernel boot → automated installation (Kickstart / Preseed / AutoYaST)
```

### DHCP configuration (ISC DHCP)

```
subnet 10.0.0.0 netmask 255.255.255.0 {
    next-server 10.0.0.10;        # TFTP server
    filename "ipxe.efi";          # Boot file (UEFI)
    option domain-name-servers 10.0.0.10;
    option routers 10.0.0.1;
}
```

### iPXE (modern PXE replacement)

- HTTP instead of TFTP (faster, more reliable)
- HTTPS support (Image verification, secure boot)
- iSCSI boot, FCoE boot
- Scriptable: `chain http://boot.example.com/script.ipxe`
- Embedded: iPXE ROM flashed directly into NIC

### PXE vs iPXE comparison

| Feature | PXE | iPXE |
|---------|-----|------|
| Protocol | TFTP (slow, 512B/block) | HTTP/HTTPS/iSCSI |
| Encryption | No | HTTPS, TLS |
| Scripting | Menu only | Full scripting engine |
| Debugging | Limited | Built-in shell |
| UEFI/BIOS | Both | Both |

## Automated installation

### Kickstart (RHEL/Alma/Rocky)

```
# Minimal kickstart for RHEL 9
text
url --url="http://10.0.0.10/install/rhel9"
lang en_US.UTF-8
keyboard us
timezone Europe/Prague --isUtc

rootpw --iscrypted $6$...

%packages
@^minimal-environment
vim
net-tools
%end

%post
echo "node001" > /etc/hostname
%end

reboot
```

### Preseed (Debian/Ubuntu)

```
d-i debian-installer/locale string en_US.UTF-8
d-i keyboard-configuration/xkb-keymap us
d-i netcfg/choose_interface select auto
d-i netcfg/get_hostname string node001
d-i clock-setup/utc boolean true
d-i time/zone string Europe/Prague

d-i partman-auto/method string regular
d-i partman-auto/choose_recipe select atomic

d-i passwd/root-login boolean true
d-i passwd/root-password password securepass
d-i passwd/root-password-again password securepass

d-i pkgsel/include string openssh-server vim
d-i finish-install/reboot_in_progress note
```

## Metal as a Service

### MAAS (Canonical)

- **Discovery**: DHCP → PXE boot → hardware detection (CPU, RAM, disk, MAC)
- **Commissioning**: node goes through commissioning, stores inventory in DB
- **Deploy**: OS image (Ubuntu, RHEL, ESXi) written to disk → reboot
- **Integration**: Juju, OpenStack, Kubernetes (Charmed Kubernetes)
- **Networking**: VLAN, subnet, DNS/DHCP management, BGP peering

### Digital Rebar / RackN

- **Provisioning**: workflow-based (stages: discovery → firmware → OS → config)
- **Multi-cloud**: bare metal + cloud + edge
- **Template**: templates for OS deployment (RHEL, Ubuntu, VMware)
- **API**: fully REST API, Terraform provider

## Management API — Redfish

### DMTF Standard

REST API (JSON) → successor to IPMI.

| Endpoint | Purpose |
|----------|---------|
| `/redfish/v1/Systems/` | Server management (power, boot, inventory) |
| `/redfish/v1/Chassis/` | Physical hardware (PSU, fan, temp, sensors) |
| `/redfish/v1/Managers/` | BMC (iLO, iDRAC, XClarity) |
| `/redfish/v1/UpdateService/` | Firmware updates |
| `/redfish/v1/EventService/` | Event subscription (webhook) |

### Redfish examples

```
# Power on server
POST /redfish/v1/Systems/1/Actions/ComputerSystem.Reset
Body: {"ResetType": "On"}

# Set boot override (one-shot PXE)
PATCH /redfish/v1/Systems/1
Body: {"Boot": {"BootSourceOverrideTarget": "Pxe", "BootSourceOverrideEnabled": "Once"}}

# Get sensor data
GET /redfish/v1/Chassis/1/Thermal
→ {"Temperatures": [{"Name": "CPU1", "ReadingCelsius": 45}], "Fans": [...]}
```

### IPMI (legacy)

- Port 623/UDP (RMCP)
- `ipmitool power on/off/status`
- `ipmitool sensor list`
- `ipmitool chassis bootdev pxe`
- Serial over LAN: `ipmitool sol activate`

## Terraform for provisioning

```hcl
# Terraform provider for VMware vSphere
provider "vsphere" {
  user           = var.vsphere_user
  password       = var.vsphere_password
  vsphere_server = var.vsphere_server
}

resource "vsphere_virtual_machine" "web" {
  name             = "web-${count.index}"
  resource_pool_id = data.vsphere_resource_pool.pool.id
  datastore_id     = data.vsphere_datastore.ds.id
  num_cpus         = 4
  memory           = 16384
  guest_id         = "rhel9_64Guest"
  network_interface { network_id = data.vsphere_network.net.id }
  disk { label = "os", size = 80 }
}
```

More in [CICD.en.md](CICD.en.md#infrastructure-as-code-iac).

## Firmware management

- **BIOS/UEFI settings**: profile update during provisioning (Redfish `PATCH /Systems/1/Bios`)
- **Firmware updates**: Redfish UpdateService, SUU (Dell), SUM (HPE), SMM (Supermicro)
- **Lifecycle Controller** (Dell LC): integrated OS for firmware management
- **Baseline management**: maintain consistent firmware versions across fleet
- **Boot: UEFI vs Legacy BIOS**:
  - **UEFI**: Secure Boot, GPT, larger disks, faster boot
  - **Legacy BIOS**: MBR, compatibility, 2 TB boot disk limit

## Configuration management (post-provisioning)

| Tool | Language | Push/Pull | Use case |
|------|----------|-----------|----------|
| **Ansible** | YAML | Push (SSH) | General config management, ad-hoc |
| **Puppet** | Ruby DSL | Pull (agent) | State management, enterprise |
| **Chef** | Ruby DSL | Pull (agent) | Compliance, infrastructure automation |
| **SaltStack** | YAML/Python | Both (salt-minion) | High-speed config, event-driven |

More in [CICD.en.md](CICD.en.md).

## OpenStack Provisioning

OpenStack offers several methods for provisioning infrastructure:

### Deployment tools

| Tool | Description | Use case |
|------|-------------|----------|
| **TripleO (OpenStack on OpenStack)** | Deploy OpenStack using bare metal (Ironic) + Heat orchestration | Production, Red Hat OSP |
| **Kolla (Ansible + Docker)** | Containerized OpenStack services, Ansible orchestration | Production, flexible |
| **Kolla-Kubernetes** | OpenStack on Kubernetes | Kubernetes-native, edge |
| **Charmed OpenStack (Juju)** | Canonical, Juju charms for OpenStack | Ubuntu, hybrid cloud |
| **OpenStack Charms** | Juju charms for individual services | Fine-grained deployment |
| **DevStack** | Fast development deployment | Dev/test, learning |
| **OpenStack-Ansible** | Ansible playbooks for OpenStack (OSA) | Legacy, AIO |

### Ironic (Bare Metal Provisioning)

- OpenStack service for managing and provisioning bare metal servers
- Supports PXE, iPXE, Redfish, IPMI
- Concepts: **Node** (HW), **Port** (MAC), **Driver** (HW type)
- Lifecycle: enroll → manage → inspect → provide → available → active
- Integration with Nova: Nova runs instances on bare metal via Ironic

### Glance (Image Management)

- Image catalog for VM images and ISO
- Supported formats: raw, qcow2, vmdk, vhd, iso
- Image caching on compute node (for faster boot)
- Multi-backend: file, Ceph RBD, Swift, NFS

## Sources

Links, books and standards: [sources/infrastructure/sources.en.md](sources/infrastructure/sources.en.md)

*Last revision: 2026-06-03*