---
- name: Set hostname
  hostname: 
    name: "{{ inventory_hostname }}"


#- name: Copy hosts file to server
#  copy:
#    src: hosts
#    dest: /etc/hosts
#    owner: root
#    group: root
#    mode: 0644

- name: Write IP-Adress of active SSH-Connection to /etc/hosts file
  debug: 
    var: ansible_facts['default_ipv4']['address']

...