Cloud-init: change default network interface name from eth0 to ens18

[everythings-gonna-be-alright]

# ls -lh
total 2.0K
-rw-r--r-- 1 root root  54 Dec 23 23:24 meta-data
-rw-r--r-- 1 root root 313 Dec 23 23:24 network-config
-rw-r--r-- 1 root root 217 Dec 23 23:24 user-data
-rw-r--r-- 1 root root 276 Dec 23 23:24 vendor-data

# cat network-config | grep 'name:'
      name: eth0

How do I change the network interface name from eth0 to ens18?
I migrated infrastructure from another provider, which used ens18 name as default.
I run Kubernetes on VMs, and for the CNI plugin, having the same interface name on each compute node is vital.

[bpg]

Hi @everythings-gonna-be-alright!

How do I change the network interface name from eth0 to ens18?

The provider doesn't do anything with regards to interface names, and honestly I don't have much ideas where the name is coming from. This behaviour could be specific for a distro you're using, or something that Proxmox is adding on top of its auto-generate cloud-init configuration, which could also be specific to PVE version.

In theory, any customization can be done via a custom cloud-init config that you can provide via network_data_file_id attribute.

I migrated infrastructure from another provider, which used ens18 name as default.

I don't have any context about "another provider", so can't comment on that.

I run Kubernetes on VMs, and for the CNI plugin, having the same interface name on each compute node is vital.

Sorry, don't quite understand the problem. Wouldn't eth0 name be same on all the nodes?

[vacquah]

Is there such a thing as : network_interface {name = ""}

I am using Talos Kubernetes, which seems to use eth0, but my pfsense bridge is on another network interface, not eth0, so running into connectivity issues. I came here looking to do the same thing as the OP - set/change network interface name . Possible?

[bpg]

Can this be done in the Proxmox UI? It seems more of a OS-level setting (or cloud-init customization) to me, rather than provider's feature.

[everythings-gonna-be-alright]

My bad. I thought generating network-config cloud-init template happens on the terraform provider side.
But actually, this provider sets the IP address and Gateway into network-config through Proxmox API.
Moreover, Proxmox API doesn't provide the ability to set custom interface names to cloud-init network templates.
The best way to resolve this issue is to generate a custom configuration and override the Proxmox cloud-init network configuration ( network_data_file_id ).
It is also necessary to manually generate mac_address and put it into the network-config template ( if you want to set a custom interface name )
Or
Just keep the default OS interface name. This way is a little bit dirty, but it will work. Here is an example:

version: 1
config:
    - type: physical
      name: ens18
      subnets:
      - type: static
        address: '${IP_ADDRESS}'
        netmask: '255.255.255.0'
        gateway: '10.15.0.1'
    - type: nameserver
      address:
      - '10.15.0.1'
      search:
      - 'my.com'

@bpg, thanks for your time.

[konstantin-kornienko]

Just sharing another possible solution.

in our case using network_data_file_id resource is not an option, because it requires ssh access to the proxmox node.

Instead, we had to rename an interface from ens18 to eth0 in our VM templates :(
This link can be used: https://techviewleo.com/change-network-interface-name-to-eth0-on-debian/
Btw the thing that names interfaces like ens18 is called Systemd predictable interface names.

Thanks to @everythings-gonna-be-alright and @bpg for sharing the information!