Title: GearBSD: managing your packages on OpenBSD

	Title: GearBSD: managing your packages on OpenBSD
	Author: Solène
	Date: 02 June 2021
	Tags: rex openbsd gearbsd
	Description:

	# Introduction

	I added a new module for GearBSD, it allows to define the exact list of
	packages you want on the system and GearBSD will take care of removing
	extra packages and installing missing packages. This is a huge step
	for me to allow managing the system from code.

	Note that this is an improvement over feeding pkg_add with a package
	list because this method doesn't remove extra packages.

	GearBSD packages in action on asciinema

	# How to use

	In the directory openbsd/packages/ of the GearBSD git repository, edit
	the file Rexfile and list the packages you want in the variable
	@packages.

	This is the packages set I want on my server.

	```Rexfile content
	my @packages = qw/
	bwm-ng checkrestart colorls curl dkimproxy dovecot dovecot-pigeonhole
	duplicity ecl geomyidae git gnupg go-ipfs goaccess kermit lftp mosh
	mtr munin-node munin-server ncdu nginx nginx-stream
	opensmtpd-filter-spamassassin p5-Mail-SpamAssassin postgresql-server
	prosody redis rss2email rsync
	/;
	```

	Then, run "rex -h localhost show" to see what changes will be done like
	which packages will be removed and which packages will be installed.

	Run "rex -h localhost configure" to apply the changes for real. I use
	"rex -h localhost" using a local ssh connection to root but you could
	run rex as root with doas with the same effect.

	# How does it work

	Installing missing packages was easy but removing extra packages was
	harder because you could delete packages that are still required as
	dependencies.

	Basically, the module looks at the packages you manually installed (the
	one you directly installed with the pkg_add command), if they are not
	part of your list of packages you want to have installed, they are
	marked as automatically installed and then "pkg_delete -a" will remove
	them if they are not required by any other package.

	# Where is going GearBSD

	This is a project I started yesterday but I've long think about it. I
	really want to be able to manage my OpenBSD system with a single
	configuration file. I currently wrote two modules that are
	independently configured, the issue is that it doesn't allow altering
	modules from one to another.

	For example, if I create a module to install gnome3 and configure it
	correctly, this will require gnome3 and gnome3-packages but if you
	don't have them in your packages list, it will get deleted. GearBSD
	needs a single configuration file with all the information required by
	all packages, this will permit something like this:

	```Configuration example
	$module{pf}{TCPports} = [ 22 ];
	$module{gnome}{enable} = 1;
	$module{gnome}{lang} = "fr_FR.UTF-8";
	@packages = qw/catgirl firefox keepassxc/;
	```

	The module gnome will know it's enabled and that @packages has to
	receive gnome3 and gnome3-extras packages in order to work.

	Such main configuration file will allow to catch incompatibilities like
	enabling gdm and xenodm at the same time.