Ubuntu Configuration Guide

This guide provides instructions for configuring Grub to support LXD and enabling root access without requiring a password. While enabling root access without a password is not strictly necessary, it can be helpful for convenience, especially on a development laptop.

Secure Boot

Ensure that Secure Boot is disabled on your system. This is often necessary for custom kernel parameters and modules.

Grub

Grub is a bootloader that manages the boot process of the operating system. Configuring Grub with specific options is necessary for certain applications like LXD to function correctly.

Edit the /etc/default/grub file using a text editor.

sudo nano /etc/default/grub

Locate the line starting with GRUB_CMDLINE_LINUX and update it to:

GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1 systemd.unified_cgroup_hierarchy=0"

Save your changes and update Grub to apply them:

sudo update-grub

Reboot your system to ensure the changes take effect:

sudo reboot

Without these modifications, CentOS 7 boxes might not network correctly, and containers may fail to obtain an IP address. If you encounter an error stating:

The container failed to acquire an IPv4 address within 30 seconds.

Then this Grub configuration change is necessary.

Enabling Root Access without Password

Root access without password prompt can simplify tasks requiring administrative rights.

Add your user to the sudoers file with no password requirement:

echo "$USER ALL=(ALL) NOPASSWD:ALL" |  sudo tee -a /etc/sudoers.d/$USER > /dev/null

While this eases access for tasks needing root privileges, be cautious and understand the security implications of allowing passwordless sudo access.