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This page describes how to create a new Kubernetes cluster via OpenStack Magnum by using Terraform or OpenTofu.

Pre-requisites

The following pre-requisites must be satisfied.

Have read and followed the EWC - IaC via Terraform and OpenTofu page.
The Terraform or OpenTofu CLI installed.
Application credentials to access the Openstack cloud project

There is a set of mandatory inputs required to create a new cluster which are:

flavor_name : the resources (CPU, RAM, Disk) configuration for the VM (see as reference EWC VM plans )
key_pair : configured SSH key which is needed to connect to the VM (see EWC - OpenStack Command-Line client for how to import it )
security_groups : security groups are sets of applied IP filter rules which define networking access to the instance
network : the network to be attached to the VM : external-internet: access to the Internet with public IP ; private-<tenant>: local private network within the tenant.

The available selectable options could also be checked using the Opnstack CLI commands :

$ openstack keypair list
 
$ openstack image list
 
$ openstack flavor list 
 
$ openstack network list

Write configuration files

Create a directory for your configuration and change directory into it:

$ mkdir example-magnum-k8s

$ cd example-magnum-k8s

Create the main configuration file to define the infrastructure:

$ touch main.tf

Open the main.tf file in a text editor and fill it as needed like in the following example :

# Define required providers
terraform {
required_version = ">= 0.14.0"
  required_providers {
    openstack = {
      source  = "terraform-provider-openstack/openstack"
      version = "~> 1.53.0"
    }
  }
}

# Configure the OpenStack Provider
provider "openstack" {
  # ...
}


resource "openstack_compute_instance_v2" "server-name" {
  name            = "server-name"
  image_name      = "image-name"
  flavor_name     = "flavor-name"
  key_pair        = "key-name"
  security_groups = ["secgroup-name-1", "secgroup-name-2", ...]

  network {
    name = "network-name"
  }
}

Replace the following fields as desired:

server-name
image-name
flavor-name
key-name
secgroup-name-1 , secgroup-name-2
network-name

For instance for ECMWF can be :

resource "openstack_compute_instance_v2" "test-server" {
  name            = "test-server"
  image_name      = "Rocky-9.4-20240717094419"
  flavor_name     = "2cpu-2gbmem-30gbdisk"
  key_pair        = "mykey"
  security_groups = ["default", "ssh"]

  network {
    name = "private-cci1-ewcloud-ms-nmhs-project"
  }
}

Run Terraform or OpenTofu to create a Kubernetes cluster via OpenStack Magnum

Initialize the directory :

Terraform

$ terraform init

OpenTofu

$ tofu init

Review the required changes:

$ terraform plan

Apply the changes to create the Kubernetes cluster :

Terraform

$ terraform apply

OpenTofu

$ tofu apply

Status can be then seen via:

Terraform

$ terraform show

OpenTofu

$ tofu show

Destroy the Cluster

The created cluster can be then destroyed by simply running:

Terraform

$ terraform destroy

OpenTofu

$ tofu destroy