mirror of
https://github.com/pygos/init.git
synced 2024-11-22 19:19:47 +01:00
114 lines
5.1 KiB
Markdown
114 lines
5.1 KiB
Markdown
# Default Service Configuration
|
|
|
|
## Pseudo Services
|
|
|
|
The default configuration contains a number of "pseudo services" in the boot
|
|
target that don't actually do anything but are merely used as anchors in
|
|
service dependencies, i.e. they indicate that some sort of milestone in the
|
|
boot sequence has been reached. Everything that is part of that milestone
|
|
specifies that it should be run *before* that pseudo service and everything
|
|
that requires that this milestone has been reached, specifies that it wants
|
|
to run afterwards.
|
|
|
|
The pseudo targets are (in the order that they are executed):
|
|
|
|
* vfs
|
|
|
|
All services that do mount point setup go before this, all service that
|
|
depend on the fully mounted rootfs go after this.
|
|
|
|
* sysinit
|
|
|
|
The system has reached a sane state, i.e. the hostname is set, the system
|
|
clock has a sane value, modules and kernel parameters are loaded, some
|
|
very basic, fundamental services are running (e.g. syslog).
|
|
Everything that is part of that setup process goes between `vfs` and
|
|
`sysinit`, everything that requires a sane setup goes *after* `sysinit`.
|
|
|
|
* network
|
|
|
|
Network configuration is done. All services that do network configuration
|
|
should position themselves between `sysinit` and `network`. Everything that
|
|
requires a fully configured networking setup should go *after* `network`.
|
|
|
|
## Default Bootup Services
|
|
|
|
This section outlines the services for the boot target that are enabled by
|
|
default.
|
|
|
|
|
|
The following services are enabled by default and run *before* the `vfs` target
|
|
for filesystem setup:
|
|
|
|
* procfs - mount `procfs` to `/proc` and try to mount additional pseudo
|
|
filesystems in `/proc` such as `binfmt_misc`
|
|
* tmpfs - mount a `tmpfs` to `/tmp`
|
|
* sysfs - mount `sysfs` to `/sys` and try to mount additional pseudo
|
|
filesystems in `/sys` (e.g. `securityfs`, `configfs`, ...)
|
|
* devfs - mount `devtmpfs` to `/dev`, try to mount additional pseudo
|
|
filesystems in `/dev` (e.g. `devpts`, `mqueue`, ...) and try to create
|
|
some additional device nodes and symlinks.
|
|
|
|
|
|
The following services are enabled by default and configured to run *after*
|
|
the `vfs` target and *before* the `sysinit` target:
|
|
|
|
* hostname - reload hostname `/etc/hostname`
|
|
* loopback - bring the loopback device up
|
|
* usyslogd - if the `usyslogd` service is compiled with this package, this
|
|
service is enabled by default and starts `usyslogd`.
|
|
* klogd - if the `klogd` daemon is compiled with this package, this service
|
|
is enabled by default and starts after `usyslogd`.
|
|
* modules - iterate over the file `/etc/modules` and try to load each module
|
|
using modprobe.
|
|
* sysctl - restore kernel parameters using `sysctl --system`. See `sysctl(8)`
|
|
for a list of possible locations that the parameters are read from.
|
|
|
|
|
|
The following services are enabled by default and configured to run *after*
|
|
the `sysinit` target and *before* the `network` target:
|
|
|
|
* ifcfg - static network configuration
|
|
Does the static network configuration outlined in [network.md](network.md)
|
|
|
|
|
|
## Default Shutdown and Reboot Services
|
|
|
|
For the shutdown and reboot targets, the following services are executed:
|
|
|
|
* sigterm - send the SIGTERM signal to all processes and wait for 5 seconds
|
|
* sigkill - send the SIGKILL signal to all remaining processes
|
|
* ifdown - bring all network interfaces down
|
|
* sync - run the sync command
|
|
|
|
|
|
## Additional Services not Enabled by Default
|
|
|
|
* agetty - A parameterizeable, respawn type `agetty` service. The first
|
|
parameter is the terminal device that the getty should run on.
|
|
* consolefont - If enabled, run once before sysinit. Sets the console font
|
|
to the first parameter.
|
|
* dhcpcdmaster - If one or more network interfaces should be configured using
|
|
dhcpcd, this service starts a central `dhcpcd` master instance.
|
|
* dhcpcd - A parameterizeable single shot service that signals the `dhcpcd`
|
|
master that it should configure a specific interface. The first parameter
|
|
is the interface that should be configured by `dhcpcd`.
|
|
* dnsmasq - A respawn type service for the `dnsmasq` DNS and DHCP server.
|
|
* hostapd - If the system should operate a WIFI access point, this respawn
|
|
type service can be enabled to manage an instace of the `hostapd` program.
|
|
* unbound - A respawn type service that manages an instance of the `unbound`
|
|
name resolver.
|
|
* usyslogd - A respawn type service that manages an instance of the `usyslogd`
|
|
syslogd implementation that is part of this package.
|
|
* hwclock - If the system has a hardware clock, this service can restore the
|
|
kernels clock from the hardware at bootup, between the `vfs` and `sysinit`
|
|
targets.
|
|
* nft - If enabled, restores net filter table rules during boot.
|
|
* swclock - For systems that don't have a hardware clock, this service
|
|
restores a somewhat usable time from a file during boot.
|
|
* swclocksave - For systems that don't have a hardware clock, this service
|
|
saves the current time to a file during shutdown or reboot.
|
|
* sshd_keygen - A wait type service that generates host keys for the OpenSSH
|
|
server and then disables itself.
|
|
* sshd - Starts an OpenSSH server after the network pseudo service and after
|
|
the sshd_keygen service.
|