# Prerequisites

## Hardware requirements

### Initial controller

> The initial controller is the machine used to bootstrap the cluster, we only need it once, you can use your laptop or desktop

- Any machine that can run Docker with the `host` networking driver ([which means only Docker on Linux hosts](https://docs.docker.com/network/host/), you can use a Linux virtual machine with bridged networking if you're on macOS or Windows)

### Servers

Any modern `x86_64` computer(s) should work, you can use old PCs, laptops or servers.

> This is the requirements for _each_ node

| Component | Minimum | Recommended |
| --------- | ------- | ----------- |
| CPU | 2 cores | 4 cores |
| RAM | 8 GB | 16 GB |
| Hard drive | 128 GB | 512 GB (depending on your storage usage, the base installation will not use more than 128GB) |
| Node count | 1 | 3 or more for high availability |

Additional capabilities:

- Ability to boot from the network (PXE boot)
- Wake-on-LAN capability, used to wake the machines up automatically without physically touching the power button

### Network setup

- All servers must be connected to the same **wired** network with the initial controller (Wifi is untested, please let me know if it works)
- You have the access to change DNS config (on your router or at your domain registrar)

## Domain

Buying a domain is highly recommended, but if you don't have one, you can also update your router config and point [`*.home.arpa`](https://datatracker.ietf.org/doc/html/rfc8375) to the load balancer (more on that later).

## BIOS setup

> You need to do it once per machine if the default config is not sufficent,
> usually for consumer hardware this can not be automated
> (it requires something like [IPMI](https://en.wikipedia.org/wiki/Intelligent_Platform_Management_Interface) to automate).

Below is my BIOS setup, your motherboard may have a different name for the options, so you'll need to adapt it with your hardware.

```json
{
    "Devices": {
        "Network Setup": {
            "PXE IPv4": true,
            "PXE IPv6": false
        }
    },
    "Advanced": {
        "CPU Setup": {
            "VT-d": true
        }
    },
    "Power": {
        "Automatic Power On": {
            "WoL": "Automatic"
        }
    },
    "Security": {
        "Secure Boot": false
    },
    "Startup": {
        "CSM": false
    }
}
```

## Gather information

- [ ] MAC address for each machine
- [ ] OS disk name (for example `/dev/sda`)
- [ ] Network interface name (for example `eth0`)
- [ ] Choose a static IP address for each machine (just the desired address, we don't set anything up yet)