examples

Boot server example

This example constructs a cluster of one boot server and two worker nodes. The worker nodes boot from the boot server. The configuration of the example is as follows:

          [ Host ]
             | 172.16.0.1
             |                     172.16.0.0/24
---+---------+------+---------------+------ net0
   |                |               |
   | 172.16.0.11    | 172.16.0.101  | 172.16.0.102
.------.       .----------.    .----------.
| boot |       | worker-1 |    | worker-2 |
'------'       '----------'    '----------'

To run the example, launch placemat by the following command:

$ sudo placemat2 cluster.example.yml

The cluster configuration is described in cluster.example.yml. The cluster contains a Network resource named net0 and three Node resources named boot, worker-1, and worker-2. It also contains an Image resource named ubuntu-image.

The network resource net0 exposes an interface as a bridge to the host, with an IP address of 172.16.0.1.

The boot node boots Ubuntu from Ubuntu Cloud Image specified by ubuntu-image, and is initialized by cloud-init. Its settings are described in user-data.example.yml and network-config.example.yml. It downloads boot images, and then starts dnsmasq and nginx on Ubuntu to work as a network boot server.

The worker nodes run Qemu's default BIOS to boot from the network. They load iPXE provided by the boot node, and then load Flatcar Container Linux. They are configured with empty disks, which will be seen as /dev/vda.

You can log-in to the boot node by ubuntu/ubuntu. As for the worker nodes, they are configured to accept auto login from the console.

$ sudo pmctl2 node enter boot        # login with ubuntu/ubuntu
$ sudo pmctl2 node enter worker-1    # autologin as "core" user

# type Ctrl-q and Ctrl-x to leave from the node console