Commissioning failed during 1st pxe install 24.04

[Michael Reed]

Following done on my MAAS 3.3.6 and 3.4 setup with Noble (24.04) setup as the Commissioning/Deployment
Commissioning fails on the very 1st boot for interfaces not configured, see details below.
If I set the commissioning OS to 22.04 then on the very 1st boot the below issue is not seen.

*20-maas-02-dhcp-unconfigured-ifaces details*
Error
"INFO: Discovered interfaces - ens3f0, ens3f1
INFO: Unconfigured IPv4 interfaces - ens3f1
INFO: Unconfigured IPv6 interfaces - ens3f0, ens3f1
INFO: Running dhclient -4 on ens3f1...
Traceback (most recent call last):
  File "/tmp/user_data.sh.NzL0wo/scripts/commissioning/20-maas-02-dhcp-unconfigured-ifaces", line 161, in <module>
    dhcp_explore()
  File "/tmp/user_data.sh.NzL0wo/scripts/commissioning/20-maas-02-dhcp-unconfigured-ifaces", line 102, in dhcp_explore
    call(["dhclient", "-nw", "-4", iface])
  File "/usr/lib/python3.12/subprocess.py", line 389, in call
    with Popen(*popenargs, **kwargs) as p:
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/subprocess.py", line 1026, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.12/subprocess.py", line 1953, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'dhclient'"

[Michael Reed (mreed8855)]

This is working in Jammy 22.04

[Björn Tillenius (bjornt)]

initramfs-tools replace dhclient with dhcpcd. We should probably do the same: https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/initramfs-tools/commit/?id=3358bc078714a2574b315e6a037bee0658cb36d3

[Jerzy Husakowski (jhusakowski)]

Using Noble for commissioning won't work until the scripts are updated to use an alternative dhcp package. This affects all MAAS versions, so we'll need to update the scripts on all supported releases. In the meantime, we can promote the Noble image to the stable channel, but it needs to be clear to the operators that changing the default commissioning image may result in errors.

The workaround is to keep using the default Ubuntu LTS version until the scripts are updated to use a different dhcp client, or to add a new commissioning script that installs isc-dhcp-client (from noble/universe) before the failing commissioning script is run.