Ansible terraform module - passing variables

[DK]

I'm hitting the following error with the terraform module. 

What am I doing wrong when passing variables? I've also tried surrounding the variables in double quotes

- terraform:

    project_path: '{{ role_path  }}/terraform/'

    state: present

    force_init: true

    variables:

        vsphere_username: foo

        vsphere_password: bar

        vsphere_server: 10.123.45.6

        datacenter_name: SAN-R720

        datastore_name: VMFS6_K8S_DS001

        network_name: Dev Network 40.x

        esxi_hosts: 10.123.45.7

        resource_pool: cluster1/Resources

        template_name: centos-vm-tmpl

        vm_name_prefix: terra-vm

        vm_num_cpus: 2

        vm_memory: 1024

        vm_guest_id: centos64Guest

        vm_scsi_type: pvscsi

        vm_ipv4_address: ["10.123.45.111"]

        vm_ipv4_gateway: 10.123.45.254

        vm_ipv4_netmask: 24  

        vm_dns_domain: my.domain.com

        vm_dns_server_list: [

            "10.123.45.253",

            "10.123.45.22",  

        ]

        vm_dns_suffix_list: [

            "dev.mycompany.com",

            "mycompany.com"

        ]

TASK [create-vms: terraform] ************************************************************************************************************************************************************

fatal: [127.0.0.1]: FAILED! => {

    "changed": false

}

MSG:

Failed to initialize Terraform modules:

Error: resource 'data.vsphere_resource_pool.resource_pool' config: unknown variable referenced: 'esxi_hosts'; define it with a 'variable' block

Error: resource 'data.vsphere_network.network' config: unknown variable referenced: 'network_name'; define it with a 'variable' block

Error: resource 'vsphere_virtual_machine.vm' count: unknown variable referenced: 'vm_ipv4_address'; define it with a 'variable' block

Error: output 'ESXi': unknown variable referenced: 'esxi_hosts'; define it with a 'variable' block