Build your own arm64 Debian LXC image. (avoid unable to open file '/etc/network/interfaces.tmp.0000000' - No such file or directory)

custom_debian_lxc_image_proxmox_arm64.md

On another Debian (x86 or arm64, doesn't matter much).

apt install distrobuilder qemu-system-common

Create a configuration file (debian.yml for example) for your LXC image :

image:
  description: |-
    Nearly stock Debian Bookworm image
  distribution: debian
  release: bookworm
  architecture: arm64

source:
  downloader: debootstrap
  same_as: bookworm
  url: http://deb.debian.org/debian/
  skip_verification: false

files:
  - path: /etc/hostname
    generator: hostname
  - path: /etc/hosts
    generator: hosts
  - path: /etc/machine-id
    generator: dump
  - path: /var/lib/dbus/machine-id
    generator: remove
  - path: /etc/network/interfaces
    generator: dump
    content: |-
      auto lo
      iface lo inet loopback

      auto eth0
      allow-hotplug eth0
      iface eth0 inet dhcp

packages:
  manager: apt
  update: true
  cleanup: true
  sets:
    - action: install
      packages:
        - dbus
        - locales
        - sudo
        - nano
        - ifupdown2

actions:
  - trigger: post-packages
    action: |-
      #!/bin/sh
      set -eux

      # Make sure the locale is built and functional
      echo "en_US.UTF-8 UTF-8" | tee --append /etc/locale.gen
      dpkg-reconfigure --frontend=noninteractive locales
      update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8

      # Install resolvconf
      echo resolvconf resolvconf/linkify-resolvconf boolean false | debconf-set-selections
      echo "REPORT_ABSENT_SYMLINK=no" >> /etc/default/resolvconf
      apt-get -y install resolvconf
      echo resolvconf resolvconf/linkify-resolvconf boolean true | debconf-set-selections
      rm /etc/default/resolvconf

      # Cleanup underlying /run
      mount -o bind / /mnt
      rm -rf /mnt/run/*
      umount /mnt

      # Cleanup temporary shadow paths
      rm /etc/*-

mappings:
  architecture_map: debian

Note that it includes ifupdown2. It is the absence of this package that triggers the errors we want to avoid.

Build the image distrobuilder build-lxc debian.yml

It should have produced two files, a

• meta.tar.xz
• rootfs.tar.xz

Navigate to your PVE templates storage, and upload rootfs.tar.xz, you're good to go.

Next time you create a Debian LXC from this, your network configuration will work out of the box.