All in one scenario

Note

This documentation is intended as a walk through of the configuration required for a minimal all-in-one overcloud host. If you are looking for an all-in-one environment for test or development, see Automated Setup.

This scenario describes how to configure an all-in-one controller and compute node using Kayobe. This is a very minimal setup, and not one that is recommended for a production environment, but is useful for learning about how to use and configure Kayobe.

Prerequisites

This scenario requires a basic understanding of Linux, networking and OpenStack.

It also requires a single host running a supported operating system (VM or bare metal), with:

  • 1 CPU

  • 8GB RAM

  • 40GB disk

  • at least one network interface that has Internet access

You will need access to a user account with passwordless sudo. The default user in a cloud image (e.g. centos or rocky or ubuntu) is typically sufficient. This user will be used to run Kayobe commands. It will also be used by Kayobe to bootstrap other user accounts.

Overview

An all in one environment consists of a single node that provides both control and compute services. There is no seed host, and no provisioning of the overcloud host. Customisation is minimal, in order to demonstrate the basic required configuration in Kayobe:

    +---------------------------+
    |       Overcloud host      |
    |                           |
    |                           |
    |      +-------------+      |
    |      |             |+     |
    |      |  Containers ||     |
    |      |             ||     |
    |      +-------------+|     |
    |       +-------------+     |
    |                           |
    +---------+-------+---------+
              |       |
              | NIC 1 |
              |       |
              +---+---+
                  |
                  |
+-----------------+------------------+ Internet

The networking in particular is relatively simple. The main interface of the overcloud host, labelled NIC 1 in the above diagram, will be used only for connectivity to the host and Internet access. A single Kayobe network called aio carries all control plane traffic, and is based on virtual networking that is local to the host.

Later in this tutorial, we will create a dummy interface called dummy0, and plug it into a bridge called br0:

+--------------+
|              |
|      OVS     |
|              |
+--------------+
        |
        |
+--------------+
|              |
|      br0     |
| 192.168.33.3 |
| 192.168.33.2 |
+--------------+
   | dummy0 |
   +--------+

The use of a bridge here allows Kayobe to connect this network to the Open vSwitch network, while maintaining an IP address on the bridge. Ordinarily, dummy0 would be a NIC providing connectivity to a physical network. We’re using a dummy interface here to keep things simple by using a fixed IP subnet, 192.168.33.0/24. The bridge will be assigned a static IP address of 192.168.33.3, and this address will by used for various things, including Ansible SSH access and OpenStack control plane traffic. Kolla Ansible will manage a Virtual IP (VIP) address of 192.168.33.2 on br0, which will be used for OpenStack API endpoints.

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