Is it possible to use a variable as a key in a key:value pair?

[Dayton Jones]

I'm trying to populate a file based on some default vars and I'm wondering if the following is possible (and if so, how?) because I've been unable to get it to work.

given:

  ansible 2.3.0.0

  python version = 2.7.13 (default, May 10 2017, 20:04:28) [GCC 6.3.1 20161221 (Red Hat 6.3.1-1)]

../defaults/main.yml

hosts:

  - {name: "{{inventory_hostname}}", '{{ansible_ec2_placement_region}}': true, "{{ansible_ec2_placement_availability_zone}}": true, test: true, group1: true}

 

host_groups:

  - name: '{{ansible_ec2_placement_region}}'    

  - name: '{{ansible_ec2_placement_availability_zone}}'

  - name: 'group1'

  - name: 'test'

../templates/groups.cfg

{% for group in host_groups %}

  group_name  {{group.name}};

  members  {{hosts|selectattr(group.name, 'defined')|map(attribute='name')|join(',')}}

{% endfor %}

../tasks/groups.yml

- name: Generate groups

  become: true

  template:

    src: groups.cfg

    dest: "{{object_dir}}/groups.cfg"

    mode: 0644

  with_items:

    - "{{host_groups}}"

 

 

I would like for the template to be converted to:

group_name  test;

members  my.host.name;

 

group_name us-west-2;

members my.host.name;

group_name us-west-2a

members my.host.name;

group_name  group1;

members  my.host.name;

but what I get is:

group_name  test;

members  my.host.name;

group_name  us-west-2;

members ;

group_name  us-west-2a;

members ;

group_name  group1;

members  my.host.name;