Persisting DHCP hostname across Debian Core container reboot

[tony6227]

Using the Debian 10 Turnkey Core container image, I can't get the container to send it's DHCP hostname to the DHCP server on boot.
I can manually add the hostname to /etc/network/interfaces but this file is reset after a shutdown/start.
Googling seems to suggest I need configuration options in /etc/systemd/network or /etc/systemd/networkd.conf but I just can't nail it.

Can anyone help?

Many thanks.

 

[Richard]

Using the Debian 10 Turnkey Core container image, I can't get the container to send it's DHCP hostname to the DHCP server on boot.
I can manually add the hostname to /etc/network/interfaces but this file is reset after a shutdown/start.
Googling seems to suggest I need configuration options in /etc/systemd/network or /etc/systemd/networkd.conf but I just can't nail it.

The hostname has to be configured in WEB GUI by Container Configuration -> 'DNS' -> 'Hostname'

 

[tony6227]

The hostname is set correctly on the "Network Configuration" page of the Webmin UI,
but it still isn't being sent as a DHCP option (#12 I believe) to the DHCP server.

I can force it manually from the command line with...

# udhcpc renew -x hostname:TESTBOX

After running this, the hostname TEXTBOX now appears in the DHCP leases on my pfSense box.
I've tried specifying udhcpc options for eth0 in /etc/dhcp/dhclient.conf but that didn't work.
Some online sources suggested udhcpc will pick-up the environment variable 'hostname' but that didn't work.

So I'm still stuck I'm afraid.

 

[Richard]

The hostname is set correctly on the "Network Configuration" page of the Webmin UI,
but it still isn't being sent as a DHCP option (#12 I believe) to the DHCP server.

Does this mean the hostname is correct but there is no hostname at all in the DHCP request? If so it's a problem of the container (and not any of Proxmox as such). Which template exactly did you use for creating the container?

 

[tony6227]

As you say, the hostname is correct in the container, but isn't seen by the DHCP server (pfSense)
I used debian-10-turnkey-core_16.0-1_amd64.tar.gz

 

[Richard]

As you say, the hostname is correct in the container, but isn't seen by the DHCP server (pfSense)
I used debian-10-turnkey-core_16.0-1_amd64.tar.gz

Run

 apt install isc-dhcp-client

and the problem will not occur any more during the next reboot.

 

[tony6227]

Success! That worked perfectly, thanks.
Does that mean there's no way to set the hostname option with the default DHCP client in the Debian template?

 

[Richard]

Does that mean there's no way to set the hostname option with the default DHCP client in the Debian template?

No - "turnkey-core" is only one kind of Debian template. You can create your own one easily by running "Convert to template" on an existing container which has installed all packages you need.