Gentoo installation script

TODO clarify:

• /boot will not be mounted to efi partition, instead /boot/efi ist the mountpoint. this prevents /boot from getting full by automated installs, and allows the kernel script to keep exactly two versions (last working kernel), and new one.
• kernel without module loading capability for security. localyesconfig

Recommendations:

• Use umask 0077
• Edit sshd_config, change port and create a sshusers group for users which may use ssh.
• Use LUKS encryption on the disk
• Use a properly configured kernel, at best restrict even USB!
• Adjust make.conf (default parallel emerge, cpu flags, binhost?)

TL;DR: Installs gentoo on a new system, suited for both servers and desktops. Optionally prepares ansible for automatic system configuration. See Install for usage instructions.

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This script will install a minimal EFI bootable gentoo system, without additional bloat. It will stick closely to the Gentoo AMD64 Handbook and Sakaki's EFI Install Guide.

What you will get:

• Minimal system configuration
• Temporary vanilla kernel (precompiled by gentoo), in my opinion you should replace this kernel with a custom made kernel for your system. See Kernel for details on how to achieve that with low effort.

What you can get optionally:

• LUKS
• EFI secure boot
• Initramfs (compiled into the kernel for EFIstub)
• Preconfigured sshd
• Ansible ready (packages, user, ssh)
• Additional packages of your choice (only trivial installations without use flag changes)

What you will NOT get: (i.e. you will have to do it yourself)

• X11 desktop environment
• A user for yourself (except root obviously)
• Any form of RAID
• A specialized kernel, see Kernel for details on how to get one.

Only necessary configuration is applied to provide a common baseline system. If you need advanced features such as an initramfs or a different partitioning scheme, you can definitely use this script but will have to make some adjustments to it.

The main purpose of this script is to provide a universal setup which should be suitable for most use-cases (desktop and server installations).

Overview of executed tasks

• Check live system
• Sync time
• Partition disks
• Format partitions
• Download stage3
• Extract stage3
• Chroot into new system
• Update portage tree
• ... TODO MISSING!

GPT

The script will create GPT partition tables. If your system cannot use GPT, this script is not suited for it.

EFI

It is assumed that your system can (and will) be booted via EFI. This is not a strict requirement, but otherwise you will be responsible to make the system bootable.

This probably involves the following steps:

• Change partition type of efi partition to ef02 (BIOS boot partition)
• Change partition name and filesystem name to boot
• Install and configure syslinux
• Adjust make.conf

Maybe there will be a convenience script for this at some point. No promises though.

Optional: Ansible ready

Optionally, this script can make the new system ready to be used with ansible.

It will do the following steps for you:

• Create an ansible user
• Generate an ssh keypair (type configurable)
• Setup a secure sshd (safe ciphers, login only with keypair)
• Install ansible

References

• Sakaki's EFI Install Guide
• Gentoo AMD64 Handbook