matrix-docker-ansible-deploy/roles/matrix-server/tasks/register_user.yml

---

- name: Fail if playbook called incorrectly
  fail: msg="The `username` variable needs to be provided to this playbook, via --extra-vars"
  when: "username is not defined or username == '<your-username>'"

- name: Fail if playbook called incorrectly
  fail: msg="The `password` variable needs to be provided to this playbook, via --extra-vars"
  when: "password is not defined or password == '<your-password>'"

- name: Ensure matrix-synapse is started
  service: name=matrix-synapse state=started daemon_reload=yes
  register: start_result

- name: Wait a while, so that Matrix Synapse can manage to start
  pause: seconds=7
  when: start_result.changed

- name: Register user
  shell: "matrix-synapse-register-user {{ username }} {{ password }}"