Gentoo image builder

README is in progress. Thank you for understanding.

TODO is here

Intro

As for me, gentoo is really good and flexible linux, but when you need to deploy it to 100 and more servers - you need a build server.

This project is an example scripts for such build server.

There will be three results of the build process:

New (latest, optimized) stage3 tarball
New stage4 taraball - this image can be deployed with minimal configuration on real server
Binary packages for different software we may need later for different setups.

Current quircks/hacks (to be removed when resolved)

gcc on rpi can't be built with lto enabled - lto is turned off for now
llvm on goldmont-plus can't be built with native optimization - core2 optimizations are used for llvm on goldmont-plus

My gentoo preferences

First of all I'm always using 'latest' packages ('unstable' gentoo). Theese are ~amd64 and ~arm64 keywords. While it is called 'unstable' it is really more stable when stable ubuntu from my point of view.
I'm using custom optimizations for different amd64 arches (broadwell, skylake, zen2, e.t.c.).

Prerequisite

In order to deploy and update images we need running at least to services:

rsync service to sync portage tree - we need to have it the same on our severs as it was be while we were building new images and binary packages
http service to provide access to binary packages repository

I'm using /var/lib/gentoo-build as a root for binary packages, tarballs and portage tree. Example config files:

rsync: rsyncd.conf
nginx: nginx-gentoo.conf

It is supposed that we're serving rsync and nginx on gentoo.example.com (this is an config option in config.yml)

Basic config

Build script is searching for config files in config folder relative to build.rb folder. Also script will merge default config.yml with config.user.yml if it will be located in current directory. It means that for basic setup you may just create config.user.yml in current folder with following content:

repository_domain: gentoo.mydomain.com

Using build script

sync

Before we can build something we should create/update portage tree (and overlays data). For this we can use sync command:

./build.rb sync

build

Build means BUILD! Build will always process from scratch, but will use binary packages and stage3 tarball from previous run.

For the first build we need to download latest stage3 tarball from gentoo download site and place it under /var/lib/gentoo-build/release/stage3-ARCH-latest.tar.xz (extension may differ).

./build.rb -a ARCH build

ARCH may be:

Concrete arch name (in default config.yml: broadwell, generic ...).
List of arch names comma separated (i.e. broadwell,generic ...).
Group name (in default config.yml: amd64 or arm64).
all to build all arches defined in config.yml

apply

All build artifacts are not transfered to 'repository' folder by default. You should run 'apply' command for that:

./build.rb apply -a ARCH

This command will transfer stage3 and stage4 tarballs to release folder and will sync binary packages to arch packages folder.

You may use -A or --apply switch to automatically apply all built arches in build command.

tmp folder is kept after build and you can chroot to it and emerge/reemerge other packages. After that you can run apply once more.

delpkg

Sometimes you need some packages to be rebuilt. In this case you should be sure that there is no binary package for it. You may use delpkg command for this:

./build.rb -a all delpkg 'sys-cluster/kubeadm'

./build.rb -a all delpkg '*/kubeadm'

kvaster/gentoo-build