proxmox_kvm: Create VM without providing vmid not idempotent

[wozniaka]

Summary

When I try to run playbook that uses community.general.proxmox_kvm module to create a new VM without specifying its vmid and with the same name more than one time, new one with different vmid is always created.

Module behaviour changed with version 7.1.0 due to issue #6155.

Possible solution is to change the following:

community.general/plugins/modules/proxmox_kvm.py

Lines 1265 to 1273 in 2e0079c

	if not vmid:
	if state == 'present' and not update and not clone and not delete and not revert and not migrate:
	try:
	vmid = proxmox.get_nextvmid()
	except Exception:
	module.fail_json(msg="Can't get the next vmid for VM {0} automatically. Ensure your cluster state is good".format(name))
	else:
	clone_target = clone or name
	vmid = proxmox.get_vmid(clone_target, ignore_missing=True)

to something like that:

   if not vmid:
        if state == 'present' and not update and not clone and not delete and not revert and not migrate:
            existing_vmid = proxmox.get_vmid(name, ignore_missing=True)
            if existing_vmid:
                vmid = existing_vmid
            else:
                try:
                    vmid = proxmox.get_nextvmid()
                except Exception:
                    module.fail_json(msg="Can't get the next vmid for VM {0} automatically. Ensure your cluster state is good".format(name))
        else:
            clone_target = clone or name
            vmid = proxmox.get_vmid(clone_target, ignore_missing=True)

Issue Type

Bug Report

Component Name

proxmox_kvm

Ansible Version

$ ansible --version
ansible [core 2.15.0]
...
    python version = 3.10.6 (main, May 29 2023, 11:10:38) [GCC 11.3.0]
...

Community.general Version

$ ansible-galaxy collection list community.general
Collection        Version
----------------- -------
community.general 7.1.0

Configuration

$ ansible-config dump --only-changed

OS / Environment

$ lsb_release -a
Distributor ID:	Debian
Description:	Debian GNU/Linux 11 (bullseye)
Release:	11
Codename:	bullseye

$ pip3 list | grep -iE "proxmoxer|requests"
proxmoxer          2.0.1
requests           2.31.0

Steps to Reproduce

Run following playbook at least to times. With each run new VM named test-vm with different vmid is created.

In this test case fist playbook run creates a VM named test-vm with vmid: 100.

- hosts: localhost
  gather_facts: false
  vars_files:
    - api_credentials.yml
  tasks:
    - name: Deploy VM
      community.general.proxmox_kvm:
        api_host: "{{ api_host }}"
        api_user: "{{ api_user }}"
        api_token_id: "{{ api_token_id }}"
        api_token_secret: "{{ api_token_secret }}"
        node: pve
        name: test-vm
        state: present

Expected Results

After discovering that VM with name test-vm already exists and no vmid was provided module shouldn't make any changes (changed: false, unless update: true or related flags are set) and return info about previously created one (as in 7.0.0)

First run:

$ ansible-playbook -v test.yml
changed: [127.0.0.1] => {
    "changed": true,
    "devices": {},
    "mac": {},
    "msg": "VM test-vm with vmid 100 deployed",
    "vmid": 100
}

Second run:

$ ansible-playbook -v test.yml
ok: [127.0.0.1] => {
    "changed": false,
    "msg": "VM with name <test-vm> already exists",
    "vmid": 100
}

Actual Results

Multiple VM instances with different vmid and the same name are created every playbook run.

First run:

$ ansible-playbook -v test.yml
changed: [127.0.0.1] => {
    "changed": true,
    "devices": {},
    "mac": {},
    "msg": "VM test-vm with vmid 100 deployed",
    "vmid": 100
}

Second run:

$ ansible-playbook -v test.yml
changed: [127.0.0.1] => {
    "changed": true,
    "devices": {},
    "mac": {},
    "msg": "VM test-vm with vmid 101 deployed",
    "vmid": 101
}

Code of Conduct

• I agree to follow the Ansible Code of Conduct

[ansibullbot]

Files identified in the description:

• plugins/modules/proxmox_kvm.py

If these files are incorrect, please update the component name section of the description or use the !component bot command.

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[ansibullbot]

cc @Ajpantuso @Thulium-Drake @UnderGreen @helldorado @joshainglis @karmab @tleguern
click here for bot help

[UnderGreen]

@wozniaka I think the previous behavior was wrong. Proxmox API allows you to create/have multiple VMs with the same name. Previously the module didn't let that, but we shouldn't restrict something which is a feature by design in API.

[UnderGreen]

@felixfontein or @russoz would like to hear your thoughts about that.

[wozniaka]

@UnderGreen I can understand that but can't module support this scenario by explicitly providing different pairs of name and vmid and keep the previous one if no vmid is provided? Module supports creating VM with name only, so i think in that case it could also be treated in unique manner.

However, I must admit that, in this case, getting vmid (as they would be needed to be defined explicitly) for mass created VM with the same name would be rather hard just by using community.general.proxmox* modules, as they're now. On the other side it's quite simple to get vmid of already deployed VM and provide playbook rather then task level idempotence.

Maybe module can provide some sort of switch between two use cases?

[UnderGreen]

I hate to add more params to the module as it already contains about twenty of them, but we need some sort of unique param for the case if only a name is provided.

[UnderGreen]

In any case notice of the changes for the user experience should be added to the module docs.