[synology]
192.168.1.111 ansible_sudo_pass='dfg78G67'

[web]
139.59.xx:8682 server_name=do1 sql_server_id=1 sql_auto_increment_increment=1
139.59.xx:8682 server_name=do2 sql_server_id=2 sql_auto_increment_increment=2

- name: "Add ssh key"
   authorized_key: user=admin key="{{ lookup('file', 'ssh_keys/id_rsa_{{ item.server_name }}.pub') }}"
   with_items: "{{ groups['web'] }}"

TASK [synology_init : Add ssh key] **********************
fatal: [192.168.1.111]: FAILED! => {"failed": true, "msg": "'unicode object' has no attribute 'server_name'"}