> ## Documentation Index
> Fetch the complete documentation index at: https://docs.regatta.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Prerequisites

> What you need before installing and running RDT to deploy RegattaDB.

Deploying RegattaDB with RDT works with two kinds of machines: the **control node**, where you install and run the RDT CLI, and the **RegattaDB nodes** that RDT connects to and configures. Make sure both sides meet the requirements below before you start.

## Control node

* **Python 3.9 or later**, with `pip` available.
* **Network access to your Python package index** (PyPI or an internal mirror) for the
  online install path. If the control node has no network access, see
  [Offline Installation](./advanced/offline-installation.mdx) instead.
* **Docker** (or a compatible CLI such as Podman), only if you plan to run RDT from a
  provided container image instead of installing it directly. See
  [Running RDT in a Container](./advanced/running-rdt-in-a-container.mdx).

### Software dependencies

RDT depends on two different kinds of packages. You don't need to install either set
manually on a normal install; they're listed here so you can verify them ahead of time
on a minimal or hardened image.

**Python packages**, installed automatically by `pip` when you install RDT:

* `ansible`
* `ansible-runner`
* `pydantic`
* `pyregatta` (Regatta's Python driver; RDT bundles a self-contained build of it)
* `typer`
* `rich`

[**Regatta client dependencies**](/drivers-and-clients/client-lib): must already be present on the control node's OS. These are required by the bundled `pyregatta` driver, which embeds a compiled client library.

## RegattaDB nodes

These nodes must meet RegattaDB's general
[self-hosted deployment prerequisites](https://docs.regatta.dev/self-hosted-deployment/prerequisites)
(OS, architecture, system packages, hardware, and connectivity). RDT adds the following
requirements on top of those, specific to how it connects to and configures nodes:

* **SSH access** from the control node to every node, using either:
  * A key pair (recommended; see `--key`/`-k` in
    [Global Options & Credentials](./advanced/global-options-and-credentials.mdx)), or
  * A shared username/password (`--ask-password` or `--password`).
* `sudo `**access** for the SSH user on every node: installing packages, writing `udev` rules, and managing `systemd` services all require root privileges. Passwordless `sudo` is preferred; a `sudo` password also works, since RDT reuses the SSH password you provide to answer the `sudo` prompt automatically.

## Choosing an installation path

* Nodes with internet access: follow [Installation](./installation.mdx) (RPM or `pip install`).
* Air-gapped nodes: follow [Offline Installation](./advanced/offline-installation.mdx).
* Running RDT itself from a container instead of installing it: follow
  [Running RDT in a Container](./advanced/running-rdt-in-a-container.mdx).

Once prerequisites are met, continue to [Installation](./installation.mdx).