This module lets you manage the DNS aspects of your ESXi host; it lets you set the hostname, domain, and the DNS resolvers:

- name: Configure the hostname and dns servers
  local_action
    module: vmware_dns_config:
    hostname: "{{ exsi_host }}"
    username: "{{ exsi_username }}"
    password: "{{ exsi_password }}"
    validate_certs: "no"
    change_hostname_to: "esxi-host-01"
    domainname: "my-domain.com"
    dns_servers:
        - "8.8.8.8"
        - "8.8.4.4"

In the previous example, we are setting the FQDN of the host to be esxi-host-01.my-domain.com and also configuring the host to use Google public DNS resolvers.