Snapshot all running VMs on Proxmox via Ansible

Operating Systems & Open Source Linux
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Hey there

I use Ansible to automate all VM updates in my Proxmox Cluster. The annoying thing currently is, that I have to snapshot every single VM by hand from Proxmox GUI before running my Playbooks.

Yes indeed, I have a Proxmox Backup Server and daily backups and additional ZFS replication of the VM storage itself, but I don’t want to rely on those to restore in case of non recoverable failure because I run the updates randomly when I have some spare time (yes yes, at least weekly). :smiley:

I know Proxmox offers the possibility to take snapshots via CMD

qm snapshot <vmid> <snapshotname>

where <vmid> has following option:

<vmid>: <integer> (1 - N)
            The (unique) ID of the VM.

So I guess i could deploy a command like this?

qm snapshot 100,101,102 before_update

Not really sure if I understand the 1-N corretly.

Either case, I don’t really want to maintain the list everytime a VM is deleted or added.

Is there a command in Proxmox to update every VM currently running with a single snapshot name for all of them or will I have to create a script that will be called from Ansible?

If I have to go with a script, how do I make Ansible wait for the script to finish before continuing with the execution and get the status back in case of failure?

Thanks in advance

2

The 1-N is describing the expected value of <vmid> (i.e., a non-zero integer – though, the valid range of Proxmox vmids is currently 100 - 999999999, rather than actually 1 - N).

Unfortunately, this means qm snapshot 100,101,102 before_update won’t work, but you can get there with a little work.

You can use qm list and a little AWK to get the IDs of all running VMs:
qm list | awk '$3 == "running" { print $1 }'

You have a couple options for how to use the results of that:

  1. Pipe to xargs to snapshot each VM (this could be run using the Ansible shell module):

    • qm list | awk '$3 == "running" { print $1 }' | xargs -I % qm snapshot % before_update

  2. Register the output as an Ansible variable, then use Ansible to iterate over the running VMs and snapshot them:

---
- hosts: all
  tasks:
    - name: Use qm list and awk to get all running vmids
      ansible.builtin.shell: qm list | awk '$3 == "running" { print $1 }'
      register: running_vmids
      failed_when: running_vmids.stderr # Check for stderr, as pipe to awk may mask a failure (e.g., qm command not found)

    - name: Snapshot each running VM
      ansible.builtin.command: "qm snapshot {{ item }} before_update"
      with_items:
        - "{{ running_vmids.stdout_lines }}"

Best of luck, and let me know if I can clarify anything for you!

2 Likes
3

Amazing, thanks a lot! I will try your solution very soon and report back if it worked, but am I positive it will.

There are some things still unclear to me in your solution but I will try reading through the documentation first. :smiley:

EDIT:
Worked like a charm, thanks again!

4

proxmox has its own api also… could use that instead of shell cmds

5

You mean something like an Ansible module? Or better ask, what would the benefit be of using the API instead of shell commands?

A quick google search didn’t yield any “official” results besides user modules, none of which supported snapshot functionality unfortunately.

Do you have a useful link with further informations?

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I haven’t checked ansible Galaxy for anything but someone likely wrote something already to use it.