Prerequisites
- Terraform instalation
- Ansible instalation
- OpenStack application credentials (~/.config/openstack/clouds.yaml)
- OpenStack security group with allow ingress traffic to TCP 22 (SSH) from terraform node

main.tf

terraform {
  required_providers {
    openstack = {
      source = "terraform-provider-openstack/openstack"
    }

    ansible = {
      source = "ansible/ansible"
    }
  }
}

provider "openstack" {
  cloud = "test-application-credentials"
}

data "openstack_compute_keypair_v2" "keypair_1" {
  name = "test-keypair"
}

data "openstack_networking_network_v2" "network_1" {
  name = "test-network"
}

data "openstack_networking_secgroup_v2" "secgroup_1" {
  # Ensure that the security group allow ingress to TCP 22 (SSH) from terraform node
  name = "test-secgroup" 
}

data "openstack_networking_port_v2" "port_1" {
  device_id  = openstack_compute_instance_v2.instance_1.id
  network_id = openstack_compute_instance_v2.instance_1.network.0.uuid
}

# data "template_file" "user_data" {
#   template = <

<strong>test-playbook.yml</strong>
<code>
---
- name: Deploy webserver(s)
  hosts: www
  # remote_user: ubuntu
  gather_facts: no
  become: true
  pre_tasks:
    - name: Wait util host is reachable by SSH
      wait_for_connection:
        timeout: 300

    - name: Gether facts
      setup:
  tasks:
    - name: Install nginx
      apt:
        update_cache: yes
        name:
          - nginx

Deploy

terraform init
terraform apply -auto-approve

Ansible Provider
https://github.com/ansible/terraform-provider-ansible
https://registry.terraform.io/providers/ansible/ansible/latest/docs

Links
https://www.redhat.com/en/blog/providing-terraform-with-that-ansible-magic