dinit-chimera

This is the core services suite for dinit as used by Chimera.

It provides an expansive collection of service files, scripts and helpers to aid early boot, more suitable for a practical deployment than the example collection that comes with upstream. Patches for third party distro adaptations are welcome, provided they are not disruptive.

Currently the documentation for the suite is lacking, which is also to be done.

Dependencies

• dinit (0.18.0 or newer)
• POSIX core utilities
  • We test chimerautils
  • Others are supported (GNU, busybox, etc.); issues should be reported
  • Needs at least coreutils equivalent, awk, and sh
• mount, umount
  • Implementation must support -a
• sulogin (any implementation, e.g. shadow, util-linux, busybox)
• sd-tools (particularly sd-tmpfiles)
• libkmod

Distribution-provided files

The distribution should provide the following helpers (the paths are the defaults, they may be altered with meson options):

• /usr/libexec/dinit-console
  • Perform console and keyboard setup; optional
• /usr/libexec/dinit-cryptdisks
  • Perform encrypted drive setup; optional
• /usr/libexec/dinit-devd
  • Perform device initialization; mandatory

The dinit-console may look like this when using console-setup:

#!/bin/sh

if [ "$1" = "keyboard" ]; then
    set -- "-k"
else
    set --
fi

exec setupcon "$@"

The dinit-cryptdisks may look like this when using Debian cryptsetup scripts:

#!/bin/sh

[ -r /usr/lib/cryptsetup/cryptdisks-functions ] || exit 0
[ -r /etc/crypttab ] || exit 0

. /usr/lib/cryptsetup/cryptdisks-functions

INITSTATE="$1"

case "$2" in
    start) do_start ;;
    stop) do_stop ;;
    *) exit 1 ;;
esac

It is passed two arguments, the first one is either early or remaining while the second one is either start or stop.

The dinit-devd may look like this when using udev:

#!/bin/sh

case "$1" in
    start) exec /usr/libexec/udevd --daemon ;;
    stop) udevadm control -e || : ;;
    settle) exec udevadm settle ;;
    trigger) exec udevadm trigger --action=add ;;
esac

exit 1

Note that currently the behaviors are subject to change. Adopters should watch out for such changes and adjust their scripts accordingly.

Optional dependencies

Not having these dependencies will allow the boot to proceed, but specific functionality will not work. Generally the affected oneshots will simply exit with success if the tools aren't located.

• fsck
  • Without it, early file system checks won't be available
  • Tested with util-linux, others may work
• mdadm
• dmraid
• LVM2
• Btrfs
• ZFS
• makedumpfile
  • For kernel crashdump support
• kexec-tools
  • For kernel crashdump support

Service targets

The collection provides special "target" services, suffixed with .target, which can be used as dependencies for third party service files as well as for ordering.

Until better documentation is in place, here is the list, roughly in bootup order. The actual order may vary somewhat because of parallel startup. In general your services should specify dependency links and ordering links for every target that is relevant to your functionality (i.e. you should not rely on transitive dependencies excessively). This does not apply to very early oneshots that are guaranteed to have run, i.e. in most cases services should not have to depend on early-prepare.target and so on.

• early-prepare.target - early pseudo-filesystems have been mounted
• early-modules.target - kernel modules from /etc/modules have been loaded
• early-devices.target - device events have been processed
  • This means /dev is fully populated with quirks applied and so on.
• early-keyboard.target - console keymap has been set
• early-fs-pre.target - filesystems are ready to be checked and mounted
  • This means encrypted disks, RAID, LVM and so on is up.
• early-root-rw.target - root filesystem has been re-mounted read/write.
  • That is, unless fstab explicitly specifies it should be read-only.
• early-fs-fstab.target - non-network filesystems in fstab have been mounted
• early-fs-local.target - non-network filesystems have finished mounting
  • This includes the above plus non-fstab filesystems such as ZFS.
• early-console.target - follow-up to early-keyboard.target (console font, etc.)
• pre-local.target - most important early oneshots have run.
  • Temporary/volatile files/dirs managed with tmpfiles.d are not guaranteed yet.
  • Most services should prefer local.target as their sentinel.
  • Typically only for services that should guarantee being up before rc.local is run.
  • All targets above this one are guaranteed to have been reached.
• local.target - /etc/rc.local has run and temp/volatile files/dirs are created
  • Implies pre-local.target.
  • Most regular services should depend on at least this one (or pre-local.target).
• pre-network.target - networking daemons may start.
  • This means things such as firewall have been brought up.
• network.target - networking daemons have started.
  • Networking daemons should use this as before.
  • Things depending on network being up should use this as a dependency.
• login.target - the system is ready to run gettys, launch display manager, etc.
  • Typically to be used as a before sentinel for things that must be up before login.
• time-sync.target - system date/time should be set by now.
  • Things such as NTP implementations should wait and use this as before.
  • Things requiring date/time to be set should use this as a dependency.
  • This may take a while, so pre-login services depending on this may stall the boot.