ansible/test/integration/targets/lookup_file/tasks/main.yml

- name: make a new file to read
  copy: dest={{output_dir}}/foo.txt mode=0644 content="bar"

- name: load the file as a fact
  set_fact:
    foo: "{{ lookup('file', output_dir + '/foo.txt' ) }}"

- debug: var=foo

- name: verify file lookup
  assert:
    that:
        - "foo == 'bar'"