Ansible async_status task - error: ansible_job_id "undefined variable" - bash

Question

I have a 3 node ubuntu 20.04 lts - kvm - kubernetes cluster, and the kvm-host is also ubuntu 20.04 lts. I ran the playbooks on the kvm-host.
I have the following inventory extract:
nodes:
hosts:
sea_r:
ansible_host: 192.168.122.60
spring_r:
ansible_host: 192.168.122.92
island_r:
ansible_host: 192.168.122.93
vars:
ansible_user: root
and have been trying a lot with async_status, but always fails,
- name: root commands
hosts: nodes
tasks:
- name: bash commands
ansible.builtin.shell: |
apt update
args:
chdir: /root
executable: /bin/bash
async: 2000
poll: 2
register: output
- name: check progress
ansible.builtin.async_status:
jid: "{{ output.ansible_job_id }}"
register: job_result
until: job_result.finished
retries: 200
delay: 5
with error:
fatal: [sea_r]: FAILED! => {"msg": "The task
includes an option with an undefined variable.
The error was: 'dict object' has no attribute
'ansible_job_id' ...
If instead I try with the following,
- name: root commands
hosts: nodes
tasks:
- name: bash commands
ansible.builtin.shell: |
apt update
args:
chdir: /root
executable: /bin/bash
async: 2000
poll: 2
register: output
- debug: msg="{{ output.stdout_lines }}"
- debug: msg="{{ output.stderr_lines }}"
I get no errors.
Also tried following variation,
- name: check progress
ansible.builtin.async_status:
jid: "{{ item.ansible_job_id }}"
with_items: "{{ output }}"
register: job_result
until: job_result.finished
retries: 200
delay: 5
that was suggested as a solution to similar error. That also does not help, I just get slightly different error:
fatal: [sea_r]: FAILED! => {"msg": "The task includes
an option with an undefined variable. The error
was: 'ansible.utils.unsafe_proxy.AnsibleUnsafeText
object' has no attribute 'ansible_job_id' ...
At the beginning and the end of the playbook, I resume and pause my 3 kvm server nodes like so:
- name: resume vms
hosts: local_vm_ctl
tasks:
- name: resume vm servers
shell: |
virsh resume kub3
virsh resume kub2
virsh resume kub1
virsh list --state-paused --state-running
args:
chdir: /home/bi
executable: /bin/bash
environment:
LIBVIRT_DEFAULT_URI: qemu:///system
register: output
- debug: msg="{{ output.stdout_lines }}"
- debug: msg="{{ output.stderr_lines }}"
and so
- name: pause vms
hosts: local_vm_ctl
tasks:
- name: suspend vm servers
shell: |
virsh suspend kub3
virsh suspend kub2
virsh suspend kub1
virsh list --state-paused --state-running
args:
chdir: /home/bi
executable: /bin/bash
environment:
LIBVIRT_DEFAULT_URI: qemu:///system
register: output
- debug: msg="{{ output.stdout_lines }}"
- debug: msg="{{ output.stderr_lines }}"
but I don't see how these plays could have anything to do with said error.
Any help will be much appreciated.

Answer 1

You get an undefined error for your job id because:
You use poll: X on your initial task, so ansible connects every X seconds to check if the task is finished
When ansible exists that task and enters your next async_status task, the job is done. And since you used a non-zero value to poll the async status cache is automatically cleared.
since the cache was cleared, the job id does not exist anymore.
Your above scenario is meant to be used to avoid timeouts with your target on long running tasks, not to run tasks concurrently and have a later checkpoint on their status. For this second requirement, you need to run the async task with poll: 0 and clean-up the cache by yourself
See the documentation for more explanation on the above concepts:
ansible async guide
ansible async_status module
I made an example with your above task and fixed it to use the dedicated module apt (note that you could add a name option to the module with one or a list of packages and ansible would do both the cache update and install in a single step). Also, retries * delay on the async_status task should be equal or greater than async on the initial task if you want to make sure that you won't miss the end.
- name: Update apt cache
ansible.builtin.apt:
update_cache: true
async: 2000
poll: 0
register: output
- name: check progress
ansible.builtin.async_status:
jid: "{{ output.ansible_job_id }}"
register: job_result
until: job_result.finished
retries: 400
delay: 5
- name: clean async job cache
ansible.builtin.async_status:
jid: "{{ output.ansible_job_id }}"
mode: cleanup
This is more useful to launch a bunch of long lasting tasks in parallel. Here is a useless yet functional example:
- name: launch some loooooong tasks
shell: "{{ item }}"
loop:
- sleep 30
- sleep 20
- sleep 35
async: 100
poll: 0
register: long_cmd
- name: wait until all commands are done
async_status:
jid: "{{ item.ansible_job_id }}"
register: async_poll_result
until: async_poll_result.finished
retries: 50
delay: 2
loop: "{{ long_cmd.results }}"
- name: clean async job cache
async_status:
jid: "{{ item.ansible_job_id }}"
mode: cleanup
loop: "{{ long_cmd.results }}"

Answer 2

You have poll: 2 on your task, which tells Ansible to internally poll the async job every 2 seconds and return the final status in the registered variable. In order to use async_status you should set poll: 0 so that the task does not wait for the job to finish.