Ansible で var から comma separated value を作成

test.yml

- hosts: localhost
  gather_facts: false

  vars:
    db:
      replicas:
        - id: 1
          dns_record: host1
        - id: 2
          dns_record: host2

  tasks:
    - set_fact:
        records: "{{ db.replicas | map(attribute='dns_record') | list | join(',') }}"

    - name: result
      debug:
        var=records

TASK [result] ***********************************************************************************************************************************************************
ok: [localhost] => {
    "records": "host1,host2"
}