Run a task on only one server in a group in inventory.

[soumya dutta]

Hi guys,

I have a situation where I need to run one task in only one server of a particular group.

For example i have inventory as below
[aws]
server1
server2

[gcp]
server3
server4

now I need to run a task on whichever server connects first and task should be run only once.
I am using when condition to run tasks on gcp group as " inventory_hostname in groups['gcp'] " but when I use run_once: true it is taking the server1 from aws group and whole task is getting skipped.

Please help and guide me.

Regards,
Soumya

[Vladimir Botka]

On Wed, 24 Jun 2020 03:33:02 -0700 (PDT)
soumya dutta <sdsoum...@gmail.com> wrote:

> ... run one task in only one server of a particular group.

>
> [aws]
> server1
> server2
>
> [gcp]
> server3
> server4

Split the playbook into two plays. For example

- hosts: aws
tasks:
- debug:
msg: Run this task on one server only
run_once: true
- hosts: gcp
tasks:
- debug:
msg: Run this task on one server only
run_once: true

You might want to put such tasks into a role. For example

- hosts: aws
tasks:
- include_role:
name: my_library_of_tasks
tasks_from: task_on_one_server_only.yml
run_once: true
- hosts: gcp
tasks:
- include_role:
name: my_library_of_tasks
tasks_from: task_on_one_server_only.yml
run_once: true

HTH,

-vlado

--
Vladimir Botka