[SOLVED] Proxmox API prune-backups invalid format

[willifehler]

Hello,

I'm trying to setup a Backup Job in Proxmox VE using the API.

root@...:~# pveversion
pve-manager/7.4-3/9002ab8a (running kernel: 5.15.107-1-pve)

My .json file:

{
   "compress":"zstd",
   "enabled":1,
   "mailnotification":"always",
   "mailto":"...",
   "mode":"snapshot",
   "notes-template":"{{guestname}}",
   "prune-backups": {
     "keep-last": "5"
   },
   "schedule":"mon..fri 00:00",
   "storage":"cephfs",
   "vmid":"112"
}

I'm getting this response:

HTTP/1.1 400 Parameter verification failed.
Cache-Control: max-age=0
Connection: close
Content-Length: 121
Content-Type: application/json;charset=UTF-8
Date: Mon, 17 Jul 2023 09:09:21 GMT
Expires: Mon, 17 Jul 2023 09:09:21 GMT
Pragma: no-cache
Server: pve-api-daemon/3.0

{
    "data": null,
    "errors": {
        "prune-backups": "invalid format - value without key, but schema does not define a default key\n"
    }
}

If I remove prune-backups the job will be created fine.

How can I pass prune-backups as a key by using the API?

Regards - Willi

 

[willifehler]

If I create a backup in the WebUI:

root@...:~# pvesh get /cluster/backup/backup-335029a3-0168
┌──────────────────┬──────────────────────┐
│ key              │ value                │
╞══════════════════╪══════════════════════╡
│ compress         │ zstd                 │
├──────────────────┼──────────────────────┤
│ enabled          │ 1                    │
├──────────────────┼──────────────────────┤
│ id               │ backup-335029a3-0168 │
├──────────────────┼──────────────────────┤
│ mailnotification │ always               │
├──────────────────┼──────────────────────┤
│ mailto           │ ...                  │
├──────────────────┼──────────────────────┤
│ mode             │ snapshot             │
├──────────────────┼──────────────────────┤
│ notes-template   │ {{guestname}}        │
├──────────────────┼──────────────────────┤
│ prune-backups    │ {"keep-last":"5"}    │
├──────────────────┼──────────────────────┤
│ schedule         │ mon..fri 00:00       │
├──────────────────┼──────────────────────┤
│ storage          │ cephfs               │
├──────────────────┼──────────────────────┤
│ type             │ vzdump               │
├──────────────────┼──────────────────────┤
│ vmid             │ 101,110,111,112      │
└──────────────────┴──────────────────────┘

So the value keep-last should be fine?!

 

[cheiss]

Hi,

if you look at the API documenation for /cluster/backup (which I assume you are using),
the prune-backups parameter does not take an (JSON) object, but rather a comma-separated string.

So in your case, the request body should look like this:

{
  ..,
  "prune-backups": "keep-last=5",
  ..
}

 

[willifehler]

It works fine. Thanks a lot Christoph!

 

[cheiss]

Great to hear that solved your problem!

Please just mark the thread as solved by editing the first post - there should be a dropdown near the title field. This helps other people with the same problem to more easily find this thread in the future!