How to access elements of a variable in ansible

I'm trying to access a specific value in a list of data and it fails, can't find the ipa variable.

Here is a short bit of the boulder.yaml vars file, yes, dual homed. Network configurations require it:

service:
  control:
  - name: "bldr0cuomdev01"
    ipa: 192.168.101.81
  - name: "bldr0cuomdev02"
    ipa: 192.168.101.82
management:
  control:
  - name: "bldr0cuomdev11"
    ipa: 10.100.78.81
  - name: "bldr0cuomdev12"
    ipa: 10.100.78.82

And I'm trying to use the following (much shorter) jinja2 template (nodes.j2) to create a file:

{{ service.control.ipa[0] }},{{ management.control.ipa[0] }}

I'm basically getting the error that ipa is not found.

Since there are two sections, having it be a loop isn't going to work but if I test just the service section as a loop, it does work. So it's able to find ipa, but my method isn't valid for some reason.

{% for s in service.control %}
{{ s.ipa }}
{% endfor %}

I saw another suggestion of using .0 instead of a bracketed array

{{ service.control.ipa.0 }},{{ management.control.ipa.0 }}

And also tried using a quoted zero

{{ service.control.ipa['0'] }},{{ management.control.ipa['0'] }}

But neither work. Searching on the 'net is common enough that my search is not finding anything relevant.

For example,
result: "{{ service.control.0.ipa }},{{ management.control.0.ipa }}"


gives
result: 192.168.101.81,10.100.78.81


StackExchange DevOps Q#16608, answer score: 2