Solution: Writing an Inventory

[all]
dbservers
loadbalancers
redis
kafka
webservers
grafana
backup
[dbserver1]
dbserver1.ourcompany.com ansible_host=192.168.1.1 ansible_user=username ansible_password=****
[dbserver2]
dbserver2.ourcompany.com ansible_host=192.168.1.2 ansible_user=username ansible_password=****
[dbserver3]
dbserver3.ourcompany.com ansible_host=192.168.1.3 ansible_user=username ansible_password=****
[lb1]
lb1.ourcompany.com ansible_host=192.168.1.4 ansible_user=username ansible_password=****
[lb2]
lb2.ourcompany.com ansible_host=192.168.1.5 ansible_user=username ansible_password=****
[lb3]
lb3.ourcompany.com ansible_host=192.168.1.6 ansible_user=username ansible_password=****
[redis1]
redis1.ourcompany.com ansible_host=192.168.1.7 ansible_user=username ansible_password=****
[redis2]
redis2.ourcompany.com ansible_host=192.168.1.8 ansible_user=username ansible_password=****
[kafka1]
kafka1.ourcompany.com ansible_host=192.168.1.9 ansible_user=username ansible_password=****
[kafka2]
kafka2.ourcompany.com ansible_host=192.168.1.10 ansible_user=username ansible_password=****
[webserver1]
webserver1.ourcompany.com ansible_host=192.168.1.11 ansible_user=username ansible_password=****
[webserver2]
webserver2.ourcompany.com ansible_host=192.168.1.12 ansible_user=username ansible_password=****
[webserver3]
webserver1.ourcompany.com ansible_host=192.168.1.13 ansible_user=username ansible_password=****
[grafana1]
grafana1.ourcompany.com ansible_host=192.168.1.14 ansible_user=username ansible_password=****
[backup1]
backup1.ourcompany.com ansible_host=192.168.1.15 ansible_user=username ansible_password=****
[dbservers]
dbserver1
dbserver2
dbserver3
[loadbalancers]
lb1
lb2
lb3
[redis]
redis1
redis2
[kafka]
kafka1
kafka2
[grafana]
grafana1
[backup]
backup1
[apache_servers]
webserver1
webserver2
[nginx_servers]
webserver3
[webservers]
apache_servers
nginx_servers