libgpiod: enable DBus

Package Information

• Package name: libgpiod
• Package version: libgpiod-2.2-r0
• Alpine version: 3.21.0_rc7
• Alpine architecture: aarch64

Summary

A DBus daemon was added in v2.2, but it was not enabled in the Alpine package. This was a highly requested feature that many will miss (see https://github.com/brgl/libgpiod/issues/47).

Current build options:

build() {
	./configure \
		--build=$CBUILD \
		--host=$CHOST \
		--prefix=/usr \
		--sysconfdir=/etc \
		--mandir=/usr/share/man \
		--localstatedir=/var \
		--enable-tools=yes \
		--disable-static \
		--enable-bindings-python
	make
}

I'll start by writing a list of the changes needed.

1. Pass --enable-dbus option at build time
2. Create the system user gpio-manager to run the daemon
3. Create the group gpio to grant its members the ability to interact with gpio lines
4. Write an OpenRC init script to manage the daemon

See io.gpiod1.conf

They only ship a systemd unit file, which is found here.

Steps to reproduce

n/a