Proxmox API - permanently set IP on Ubuntu VM

[Rasto Carnecky]

Hello, could you pls help me with network configuration of Ubuntu 20.04 VM via Rest API ? I need to permanently set IP for network interface ens18, tried it like this:
1) curl POST api2/json/nodes/<node_name>/qemu/<vm_id>/config {"ipconfig0": "name=ens18,ip=XXX.XXX.XXX.XXX/24,gw=XXX.XXX.XXX.XXX"} -> response 200 but no change of IP ...kinda expected

2) curl POST api2/json/nodes/<node_name>/qemu/<vm_id>/config {"net0": "virtio=XX:XX:XX:XX:XX:XX,bridge=vmbr0,firewall=1,ip=XXX.XXX.XXX.XXX/24"}
-> "net0":"invalid format - format error\nnet0.ip: property is not defined in schema ...

What is the proper way to achieve permanent change of IP ?

 

[Folke]

Hi,
Proxmox can't directly set the IP inside a VM, because it has no control over the VMs network stack. Setting the IP via the ipconfig[n] option is a feature of cloud-init. If you have cloud-init set up, AFAIK you still need to restart the VM so it reevaluates the cloud-init config.
Another possibility would be to use the qemu-guest-agent if it is installed on your target system. You can use it to execute arbitrary commands inside the VM [0].

[0] https://forum.proxmox.com/threads/about-use-agent-config-ip-address-all-faile.69728/