Nested loop in Ansible

Question

I am aware of the nested loops documentation here: http://docs.ansible.com/ansible/playbooks_loops.html#nested-loops I have 3 servers: say server1, server2, server3. I need to run a command in this fashion:

Run command on server1
Run command on server1, Run command on server2
Run command on server1, Run command on server2, Run command on server3

Any idea how I can do this using loops in ansible? I know how I can run nested loops using loop and product filter. But dont know how I can handle my particular case using Ansible.

Answer 1

It depends on the structure of the data. For example, the playbook would do the job

- hosts: server1,server2,server3
  vars:
    batch001:
      - command: "foo"
        hosts: [server1]
      - command: "bar"
        hosts: [server1, server2]
      - command: "baz"
        hosts: [server1, server2, server3]
  tasks:
    - command: "{{ item.command }}"
      loop: "{{ batch001 }}"
      when: inventory_hostname in item.hosts

Next option would be to create a dictionary of servers with nested lists of commands. For example,

- hosts: server1,server2,server3
  vars:
    batch002:
      server1:
        commands: ["foo", "bar", "baz"]
      server2:
        commands: ["foo", "bar"]
      server3:
        commands: ["foo"]
  tasks:
    - command: "{{ item }}"
      loop: "{{ batch002[inventory_hostname]['commands'] }}"