demo.yml

---
- name: Create instance(s)
  hosts: localhost
  gather_facts: no
  connection: local

  vars:
    machine_type: n1-standard-1 # default
    image: debian-7
    service_account_email: [email protected]
    credentials_file: /my/path/demo_ansible.json 
    project_id: my-project-1

  tasks:
    - name: Launch instances
      gce:
          instance_names: dev
          machine_type: "{{ machine_type }}"
          image: "{{ image }}"
          service_account_email: "{{ service_account_email }}"
          credentials_file: "{{ credentials_file }}"
          project_id: "{{ project_id }}"
          tags: webserver
      register: gce