test.yml

- hosts: all
  sudo: true
  roles:
    - Stouts.mongodb
  vars:
    - mongodb_conf_replSet: rs0
    - mongodb_conf_bind_ip: 192.168.111.11
    - mongodb_shell:
      rs.initiate()
  

test2.yml

I use the following playbook:

---
- hosts: all
  sudo: true
  vars:
    mongodb_conf_replSet: rs0/192.168.111.11:27017
    mongodb_conf_bind_ip: 192.168.111.11
    mongodb_shell:
      test:
        - rs.initiate()
  roles:
    - Stouts.mongodb

After installation I checked:

MongoDB shell version: 3.2.1
connecting to: 192.168.111.11:27017/test
> db.getName()
test
> show databases
admin  (empty)
local  0.078GB
>