Question on the multiple loop structure in my playbook

Hi All ,

I trying to modify the sshd_config parameter using the lineinfile ansible module . I would like to delegate this to multiple host . As we have used the loop twice its unable to resolve the loop structure.

vars:
ssh_delegate_hosts:

  • “192.50.26.248”

  • “192.50.27.248”

  • name: Change configuration in sshd_config

ansible.builtin.lineinfile:
path: /etc/ssh/sshd_config
regexp: “{{ item.regexp }}”
line: “{{ item.line }}”
loop:

  • { regexp: ‘^AllowTcpForwarding’, line: ‘AllowTcpForwarding yes’ }
  • { regexp: ‘^AllowAgentForwarding’, line: ‘AllowAgentForwarding yes’ }
    loop: “{{ ssh_delegate_hosts }}”
    delegate_to: “{{ item }}”

Need your valuable feedback of how to loop both the lines and loop the hosts .

Thanks and Regards,
Deepak Kumar

You haven’t described the actual overarching thing you’re trying to do with this, sometimes describing the larger task can be useful in terms of providing better guidance.

But reading between the lines, is there any reason you can’t place your intended delegation hosts into an inventory group and address them directly? For example if they’re getting special treatment as intended jumphosts or similar. Group them accordingly and run the bits of automation that’s unique to that intended system role against those group members.

I’d also tend to prefer a Jinja template over lineinfile for config if possible especially if you need to accommodate different conditional scenarios. It’s potentially a little more effort to start, but will save you pain in the long run.

That said, I think you can probably achieve what you’re trying to do with a product filter? (There’s probably easier ways to get the outcome you want too.)

https://www.packetswitch.co.uk/how-to-use-ansible-loops-with-examples/
https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_loops.html#iterating-over-nested-lists

Here’s a simplified example, you’d need to modify slightly to pull out the specific elements:

  • name: debug vars
    hosts: localhost
    gather_facts: no

vars:
delegates:

  • host1
  • host2
    regexes:
  • regex: AllowTcpForwarding
    line: AllowTcpForwarding yes
  • regex: AllowAgentForwarding
    line: AllowAgentForwarding yes

tasks:

  • name: Do some stuff
    debug:
    msg: “Doing {{ item.1 }} on {{ item.0 }}”
    delegate_to: “{{ item.0 }}”
    loop: “{{ delegates | product(regexes) | list }}”

Which would do:

(ansible)$ ansible-playbook test/debug.yml

PLAY [debug vars] ******************************************************************************************************

TASK [Do some stuff] ***************************************************************************************************
ok: [localhost → host1] => (item=[‘host1’, {‘regex’: ‘AllowTcpForwarding’, ‘line’: ‘AllowTcpForwarding yes’}]) => {
“msg”: “Doing {‘regex’: ‘AllowTcpForwarding’, ‘line’: ‘AllowTcpForwarding yes’} on host1”
}
ok: [localhost → host1] => (item=[‘host1’, {‘regex’: ‘AllowAgentForwarding’, ‘line’: ‘AllowAgentForwarding yes’}]) => {
“msg”: “Doing {‘regex’: ‘AllowAgentForwarding’, ‘line’: ‘AllowAgentForwarding yes’} on host1”
}
ok: [localhost → host2] => (item=[‘host2’, {‘regex’: ‘AllowTcpForwarding’, ‘line’: ‘AllowTcpForwarding yes’}]) => {
“msg”: “Doing {‘regex’: ‘AllowTcpForwarding’, ‘line’: ‘AllowTcpForwarding yes’} on host2”
}
ok: [localhost → host2] => (item=[‘host2’, {‘regex’: ‘AllowAgentForwarding’, ‘line’: ‘AllowAgentForwarding yes’}]) => {
“msg”: “Doing {‘regex’: ‘AllowAgentForwarding’, ‘line’: ‘AllowAgentForwarding yes’} on host2”
}

PLAY RECAP *************************************************************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Thank you very much you have in detail describe to handle multiple loops by using the product and list in the ansible playbook . Basically this was a admin script out of box requirements as we are not include in our repository so that the reason we could not leverage the out environmental inventory.

Once again Thank you so much … I appreciate the help .

Thanks
Deepak Kumar