I have defined a main playbook, which calls another preparation playbook via import_playbook.

The preparation playbook returns credentials for an S3 repository, var is called “service_secrets” at the moment, which is a dict (see below). This dict needs to be appended into the last item of product.dependencies. The indicator to pick the specific listitem could be just “Source=S3”.

---
- name: 'Preparation'
  ansible.builtin.import_playbook: 'playbook_preparation.yml'
  vars:
    product:
      name: 'mssql'
      dependencies:
        - Name: 'SqlServer'
          Source: 'psgallery'
          Type: 'psmodule'
        - Name: 'SqlServerDsc'
          Source: 'psgallery'
          Type: 'dscmodule'
        - Name: 'AWSPowershell.NetCore'
          Source: 'psgallery'
          Type: 'psmodule'
        - Name: 'ComputerManagementDsc'
          Source: 'psgallery'
          Type: 'dscmodule'
        - Name: >-
            {{
              ["mssql", ci.attributes.input_parameters.mssql.version,
              ci.attributes.input_parameters.mssql.edition,
              ci.attributes.input_parameters.mssql.language]
              | join("_")
            }}
          Source: 'S3'
          Type: 'iso'
          Bucket: 'repository'

The new fact “service_secrets” looks something like this:

        "service_secrets": {
            "Access_key_id": "abc",
            "Access_key_secret": "defghi",
            "Bucket": "repository",
            "Endpoint": "https://s3.abc.com"
        }

I tried to fiddle around with combine(), but i could not get the service_secrets into the last listitem.

    - name: DEBUG
      debug:
        msg: '{{ product | combine({"dependencies": [service_secrets]}, list_merge="append") }}'
      loop: '{{ product.dependencies }}'
      when: 'item.Source == "S3"'

This will result in:

ok: [localhost] => (item={'Name': 'mssql_2022_standard_en', 'Source': 'S3', 'Type': 'iso', 'Bucket': 'repository'}) => {
    "msg": {
        "dependencies": [
            {
                "Name": "SqlServer",
                "Source": "psgallery",
                "Type": "psmodule"
            },
            {
                "Name": "SqlServerDsc",
                "Source": "psgallery",
                "Type": "dscmodule"
            },
            {
                "Name": "AWSPowershell.NetCore",
                "Source": "psgallery",
                "Type": "psmodule"
            },
            {
                "Name": "ComputerManagementDsc",
                "Source": "psgallery",
                "Type": "dscmodule"
            },
            {
                "Bucket": "repository",
                "Name": "mssql_2022_standard_en",
                "Source": "S3",
                "Type": "iso"
            },
            {
                "Access_key_id": "abc",
                "Access_key_secret": "defgh",
                "Bucket": "repository",
                "Endpoint": "https://s3.abc.com"
            }
        ],
        "name": "mssql"
    }
}

To make it more clear: The last two listitems of product.dependencies should be one item.