iac/ansible/playbooks/docker-count.yml

---
- name: Count Docker containers on all hosts
  hosts: all
  gather_facts: false
  tasks:
    - name: Count running Docker containers on each host
      shell: "docker ps -q | wc -l"
      register: container_count
      changed_when: false

    - name: Display count for each host
      debug:
        msg: "Host {{ inventory_hostname }} has {{ container_count.stdout }} running Docker containers"

- name: Aggregate total count
  hosts: localhost
  gather_facts: false
  tasks:
    - name: Collect container counts from all hosts
      set_fact:
        container_counts: >-
          {{ hostvars | dict2items | selectattr('value.container_count', 'defined') |
          map(attribute='value.container_count.stdout') | map('int') | list }}

    - name: Display total running Docker containers
      debug:
        msg: "Total running Docker containers across all hosts: {{ container_counts | sum }}"