Trees¶

A tree is a named set of services. You bring the set up or down as one, and you decide which sets a boot brings up.

Why bother¶

The usual example. You have three groups of things:

Tree	Services
`net`	`dhcpcd`, `wpa_supplicant`, a time daemon
`print`	`cupsd`, a network filesystem
`graphic`	the X server, `dbus`, a notification daemon

Boot into a console session with only net enabled, and that is all that starts. Later, print something: 66 tree start print brings up everything printing needs, and 66 tree stop print puts it all away again, without you having to remember which daemons were involved.

The two trees you already have¶

global is created for you. A service enabled without naming a tree lands here. Delete it and the next 66 command recreates it.
boot appears when the boot module is enabled. It holds what brings the machine up.

Create and populate¶

# 66 tree create net
# 66 tree enable net
# 66 -t net enable dhcpcd wpa_supplicant
# 66 tree start net

66 tree enable is what makes the tree start at the next boot. Creating it is not enough.

The -t option also creates a tree that does not exist yet, so the explicit create above is optional. It is written out here because being explicit costs one line and saves a surprise.

Trees can be configured at creation time:

# 66 tree create -o depends=net print

for instance, depends= names trees that must start first and so, every services associated to the tree net.

Inspect¶

$ 66 -z tree status
$ 66 -z tree status -g net
$ 66 tree status -nf enabled net

The fields are name, current, enabled, allowed, groups, depends, requiredby and contents.

Start, stop, free¶

# 66 tree start net
# 66 tree stop net
# 66 tree free net

stop brings the services down but leaves them supervised. free also removes them from supervision and free any resources used by the service.

The current tree¶

# 66 tree current net

After this, 66 commands taking -t act on net without you passing the option.

Groups¶

A tree can belong to a group: boot, admin, user, or none. Only the boot group currently changes behaviour.

Trees in the boot group cannot be enabled by hand

66 tree enable refuses on a tree in the boot group. Those trees are managed by 66 itself during boot: it initiates every tree of the boot group, or only the tree named by TREE= in /etc/66/init.conf when that key is set.

This is why the install from an Arch host only enables boot@system and never enables the boot tree.

Removing¶

# 66 tree remove net

This is the supported way to get rid of a tree. Deleting directories by hand is not.