neale/homepage
neale
/
homepage
1
0
Fork 0
Code Pull Requests Actions Activity

Update runit paper

This commit is contained in:
Neale Pickett 2014-10-27 01:15:39 +00:00
parent 8b7b85b057
commit 73afd3b4c0
1 changed files with 133 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

175
papers/arch-runit.mdwn
View File

@ -122,6 +122,18 @@ You might want to play with that and understand what the initrd is,
before you are put into a position where you *have* to use it and can't start a web browser. before you are put into a position where you *have* to use it and can't start a web browser.
WARNING
-------
This document is now pretty old.
It's unlikely it will work at all on a modern Arch installation.
[My AUR](https://aur.archlinux.org/packages/runit-init/)
is usually only a few days behind the latest change in Arch's packages.
I've left this here because it might help people trying similar things
with different distributions.
But if you're using Arch, I strongly recommend you start with the AUR.
Let's go Let's go
-------- --------
@ -159,68 +171,123 @@ Be sure to move the old `init` to soming like `init.sysv`,
then create a new `init` similar to this then create a new `init` similar to this
(don't forget to `chmod +x`): (don't forget to `chmod +x`):
#! /bin/sh
PATH=/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin #! /bin/sh
export PATH
if [ $$ -ne 1 ]; then PATH=/usr/bin; export PATH
case $1 in
6)
exec kill -15 1
;;
0)
exec kill -12 1
;;
esac
echo "LOL: runit doesn't have run levels" 1>&2 if [ $$ -ne 1 ]; then
exit 1 case $1 in
fi 6)
exec kill -15 1
;;
0)
exec kill -12 1
;;
esac
# Run arch's sysinit echo "LOL: runit doesn't have run levels" 1>&2
if ! /etc/rc.sysinit; then exit 1
# Kludge it if there's no rc.sysinit fi
mount -t proc proc /proc -o nosuid,noexec,nodev echo
mount -t sysfs sys /sys -o nosuid,noexec,nodev echo 'Arch Linux'
mount -t tmpfs run /run -o mode=0755,nosuid,nodev echo 'http://www.archlinux.org/'
mount -t devtmpfs dev /dev -o mode=0755,nosuid echo '-----------------------------'
mkdir -p /dev/{pts,shm} echo
mount -t devpts devpts /dev/pts -o mode=0620,gid=5,nosuid,noexec
mount -t tmpfs shm /dev/shm -o mode=1777,nosuid,nodev
# This doesn't ever run fsck :< echo ":: Mounting initial filesystems"
mount -o remount,rw / mountpoint -q /proc || mount -t proc proc /proc -o nosuid,noexec,nodev
mountpoint -q /sys || mount -t sysfs sys /sys -o nosuid,noexec,nodev
mountpoint -q /run || mount -t tmpfs run /run -o mode=0755,nosuid,nodev
mountpoint -q /dev || mount -t devtmpfs dev /dev -o mode=0755,nosuid
: < /etc/hostname > /proc/sys/kernel/hostname mkdir -p -m0755 /run/runit /run/lock /run/lock/lvm /run/lvm /run/user /dev/pts /dev/shm
mountpoint -q /dev/pts || mount -n -t devpts devpts /dev/pts -o mode=0620,gid=5,nosuid,noexec
mountpoint -q /dev/shm || mount -n -t tmpfs shm /dev/shm -o mode=1777,nosuid,nodev
hwclock --systz mount -o remount,ro /
# Start/trigger udev, load MODULES, and settle udev echo ":: Setting up Unicode"
udevd_modprobe sysinit for i in /dev/tty[0-9]*;do
fi unicode_start <$i
done &
echo ":: Setting system clock"
hwclock --utc --hctosys
if grep -q 'break=init' /proc/cmdline; then echo ":: Enabling devices"
echo 'Breaking before init, type "exit" to continue booting' touch /dev/mdev.seq
/bin/sh /usr/bin/mdev -s &
fi
echo ":: Loading drivers"
for i in $(seq 2); do
find /sys -name modalias -type f -exec cat {} + | sort -u | xargs modprobe -b -a
done 2>/dev/null
# XXX: Who creates this? echo ":: Bringing up network"
rm /run/nologin ip link set up dev lo
cat /etc/hostname >/proc/sys/kernel/hostname
# Hand off to runit echo ":: Setting up cryptographic devices"
exec runsvdir -P -s runit-signal /service grep "^[^#]" /etc/crypttab | while read name device password options; do
case $options in
*swap*)
cryptsetup --key-file /dev/urandom open --type plain $device $name
mkswap /dev/mapper/$name
;;
*)
cryptsetup luksOpen $device $name < /dev/console
;;
esac
done
This will still run `udev` and `bootlogd` from `/etc/rc.sysinit`. echo ":: Checking filesystems"
I tried to set up `mdev` from busybox as a `udev` replacement, [ -f /forcefsck ] || grep -q forcefsck /proc/cmdline && FORCEFSCK=-f
but Xorg wants `udev`, if ! [ -f /fastboot ] && ! grep -q fastboot /proc/cmdline; then
and I was having other problems getting drivers loaded, fsck -A -T -C -a -t noopts=_netdev $FORCEFSCK
so I'm just trusting the the Arch devs here. if [ $? -gt 1 ]; then
If you can figure out another way, sulogin
please email me about it, I'd love to know. fi
fi
echo ":: Mounting filesystems"
mount -o remount,rw /
mount -a -t "nosysfs,nonfs,nonfs4,nosmbfs,nocifs" -O no_netdev
echo ":: Enabling swap"
swapon -a
echo ":: Tidying up"
install -m0664 -o root -g utmp /dev/null /run/utmp &
rm -f /etc/nologin /forcefsck /forcequotacheck /fastboot &
if grep -q 'break=init' /proc/cmdline; then
echo 'Breaking before init, type "exit" to continue booting'
/bin/sh
fi
if [ -x /etc/rc.local ]; then
echo ":: Sourcing /etc/rc.local"
. /etc/rc.local
fi
echo ":: Passing control to runit"
echo
exec runsvdir -P -s runit-signal /service
This does a couple things:
1. Mounts /proc, /sys, /dev, and some other directories.
2. Turns on Unicode for 9 TTYs
3. Sets the system clock from the hardware clock
4. Runs an initial mdev to populate /dev
5. Loads modules for things in /sys
6. Bring up the loopback interface
7. Initialize your cryptfs, if you have any in /etc/crypttab
8. fsck then mount everything in /etc/fstab
9. Run whatever's in /etc/rc.local
10. Start runsvdir
You may also want to install the `dash` package, You may also want to install the `dash` package,
and link `/bin/sh` to that, and link `/bin/sh` to that,
@ -292,17 +359,17 @@ Here's my `/usr/local/sbin/runit-signal`
15) # SIGTERM: reboot 15) # SIGTERM: reboot
cleanup cleanup
echo "Rebooting..." echo "Rebooting..."
reboot -f busybox reboot -f
;; ;;
10) # SIGUSR1: halt 10) # SIGUSR1: halt
cleanup cleanup
echo "Halting..." echo "Halting..."
halt -f busybox halt -f
;; ;;
12) # SIGUSR2: power 12) # SIGUSR2: power
cleanup cleanup
echo "Shutting down..." echo "Shutting down..."
poweroff -f busybox poweroff -f
;; ;;
*) # Everything else *) # Everything else
;; ;;
@ -363,8 +430,12 @@ You're an Arch Linux sysadmin,
you should know what you need, you should know what you need,
and I can't help you past here. and I can't help you past here.
Removing `udev` Hotplug events won't work, though.
--------------- For that, you need to either run udev or some other hotplug listener.
Setting up `mdev` as a hotplug listener
---------------------------------------
The `mdev` utility of busybox can replace most of what `udev` does. The `mdev` utility of busybox can replace most of what `udev` does.
You just need to have the kernel run `mdev` as the hotplug userspace thingy. You just need to have the kernel run `mdev` as the hotplug userspace thingy.