maps ec2 facts to host vars

map_host_vars.yml

#
# maps the hostvars from ec2 tags in the dynamic inventory to the var names expected by our roles
# this allows us to have no host var files and alsonot have host specific vars in the group_vars files as these are only evaluated in the scope
# of the current host the play is being applied to i.e. all host dont have a seperate copy of all the facts.
# this leads to a dangerous situation when using jinja2 loops over nodes in groups and then accessing hostvars 
# (that have been set in the groupvars) for that node
#

- hosts: all
  tasks:
  - set_fact: HOST_IP="{{ ec2_private_ip_address }}" ansible_ssh_host="{{ inventory_hostname }}"

- hosts: zookeeper
  tasks:
  - set_fact: ZOOKEEPER_SERVER_ID="{{ ec2_tag_zookeeper_server_id }}"

- hosts: kafka
  tasks:
  - set_fact: KAFKA_BROKER_ID="{{ ec2_tag_kafka_broker_id }}"