splunk_tags.conf

# AWS EC2 hosts
# using ANSIBLE to assign tags

{% macro eze(tag) -%}
{# this is an easy, consistent way to enable a tag #}
{{ tag }} = enabled
{%- endmacro %}

{# loop thru all your EC2 hosts in alpha order #}
{% for i in ansible_play_batch | sort %}

{# set the node name AND node vars #}
{% set node_name=i %}
{% set node_vars=hostvars[ i ] %}

# tags for {{ node_name }}
[host={{ node_name }}]

{# set custom enviro tag -- dev, stage, prod, etc #}
{{ eze(node_vars.enviro) }}

{# set std AWS metadata tag -- region, AZ, etc #}
{{ eze(node_vars.ansible_ec2_placement_region) }}
{{ eze(node_vars.ansible_ec2_instance_id) }}
{{ eze(node_vars.ansible_ec2_placement_availability_zone) }}

{# set custom tag if condition is met -- app type, etc #}
{% if node_vars.app_type is defined %}
{{ eze(node_vars.app_type) }}
{% endif %}

...

{% endfor %}