ELB info: return all LB if names is not defined

[christophemorio]

SUMMARY

Documentation says

options:
  names:
    description:
      - List of ELB names to gather information about. Pass this option to gather information about a set of ELBs, otherwise, all ELBs are returned.

But doing this elb_classic_lb_info returns an empty list.

ISSUE TYPE

• Bugfix Pull Request

COMPONENT NAME

elb_classic_lb_info

ADDITIONAL INFORMATION

- hosts: localhost
  tasks:
  - community.aws.elb_classic_lb_info: {}
    register: elb_info

  - debug: var=elb_info

$ ansible-playbook playbook.yaml
TASK [community.aws.elb_classic_lb_info] ********
ok: [localhost]

TASK [debug] ********
ok: [localhost] => {
    "elb_info": {
        "changed": false,
        "elbs": [],  # <-- should return list of all ELB
        "failed": false
    }
}

[ansibullbot]

cc @jillr @markuman @mjschultz @nand0p @s-hertel @tremble @wimnat
click here for bot help

[tremble]

Thanks for taking the time to raise this PR. I encountered this issue a couple of days ago when working on converting elb_classic_lb over to boto3 (ansible-collections/amazon.aws#377) and hadn't had chance to look into it yet.

From a quick look the code looks reasonable.

Please could you also add a test to https://github.com/ansible-collections/community.aws/blob/main/tests/integration/targets/elb_classic_lb/tasks/main.yml it only needs to be something as simple as

        - elb_classic_lb_info:
            names: '{{ omit }}'
          register: info

        - assert:
            that:
              - info.elbs | length > 0

[tremble]

recheck

[ansible-zuul]

LGTM!