Introduction to Terraform

While a complete discussion around Terraform is outside the scope of this Lab, this section provides some basic background information to ensure that you understand Terraform operations and functions.

Terraform Providers

Unlike Ansible, Terraform is a precompiled, single binary application. However, this binary does not include any built-in ability to apply configuration to or read configuration from any device. This functionality is given through the installation of a provider, a set of resource and data source declarations that instruct Terraform how to interact with a device's REST APIs. Terraform has no ability to interact with any device via SSH, so any provider operates solely using APIs.

Providers are not hosted within Hashicorp's infrastructure. A provider owner places it within their own repository and registers the provider to the Terraform Registry. The registry enables anyone to use the provider through a declaration at the top of any HCL file. You can also reference a provider that is not registered within the public registry, either in an organization's VCS or using a private Terraform registry.

A provider declaration for NDFC is as follows:

terraform {
  required_providers {
    ndfc = {
      source  = "CiscoDevNet/ndfc"
      version = "0.3.0"
    }
  }
}

provider "ndfc" {
  username = "admin"
  password = "cisco.123"
  url      = "https://10.15.0.98"
  insecure = true
}

After the declaration, you place the HCL configuration that is required to move the end device to the desired state. The provider is not downloaded and installed, however, until a terraform init process is executed.

Terraform Documentation

All documentation for each (public) provider can be found through the Terraform Registry. Each provider listing has information about the general use of the provider, as well as the specific resources (items to which configuration can be applied) and data sources (items from which configuration can be read).

Make sure you are in your root Ansible directory

cd ~/workspace/ndlab/nac

Create the playbook that will remove the switches from your Site1 Fabric

touch ~/workspace/ndlab/nac/remove_switches.yml
cat << EOF > ~/workspace/ndlab/nac/remove_switches.yml

---
# This Ansible Playbook Is Used To Remove Switches from Site1
- name: Remove Switches from ND Fabrics
  hosts: nd
  gather_facts: false

  tasks:
    - name: Remove Switches From All Sites
      cisco.dcnm.dcnm_rest:
        method: DELETE
        path: "/api/v1/manage/fabrics/site1-fabric/switches/{{ item }}"
      register: result
      loop:
        - 9RU4HDYCH3I
        - 9AG4VMSA335
        - CONNECT_TIMEOUT
        - 9BV7KYBQBIS

EOF

Run the playbook to remove the switches from your Site1 Fabric

ansible-playbook -i hosts.site1.yml remove_switches.yml

Terraform Setup

Return to your Visual Studio Code Terminal window

Step 1 - Create a new project directory for Terraform

Create a directory called terraform under the /home/cisco/Documents/ndfclab project directory.

mkdir -p ~/workspace/ndlab/terraform
cd ~/workspace/ndlab/terraform

Step 2 - Within directory ~/workspace/ndlab/terraform project directory, create directory modules

This is the directory where all the terraform modules will be created:

mkdir -p ~/workspace/ndlab/terraform/modules

Step 3 - Install Hashicorp Terraform

There are several steps required to install Terraform which were taken care of already to conserve time. If you are interested in the complete steps, please refer to the Hashicorp Terraform Install Guide. To install Terraform you would need to execute the following command in your Visual Studio Code Terminal:

sudo apt-get install terraform=1.14.5-1

If you are prompted for a password, use the password cisco.123 to continue.

Step 4 - Verify Terraform is installed correctly by checking the version

terraform version

    Terraform v1.14.5
    on linux_amd64