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====== OpenRC ======

OpenRC is a dependency based init system.

===== Features =====

OpenRC provides a number of features like hardware initiated initscript run and cgroups support, without requiring large layout changes.

====== Installation ======

Two [[slackware:slackbuild_scripts|Slackbuilds]] are available, [[http://slackbuilds.org/repository/14.2/system/openrc/|openrc]], which contains the OpenRC init system, and [[http://slackbuilds.org/repository/14.2/system/openrc-services/|openrc-services]], which contains various services for use with OpenRC.

===== Post installation =====

After installation, some steps are needed to boot with OpenRC.

=== Setup the agetty services ===

  # main tty
  ln -s /etc/openrc/init.d/agetty /etc/openrc/init.d/agetty.tty1
  /sbin/rc-update add agetty.tty1 default
    
  cp /etc/openrc/conf.d/agetty /etc/openrc/conf.d/agetty.tty1
  echo 'agetty_options="--noclear"' >> /etc/openrc/conf.d/agetty.tty1
  
  # additional ttys
  for i in {2..6}; do
    ln -s /etc/openrc/init.d/agetty /etc/openrc/init.d/agetty.tty${i}
    /sbin/rc-update add agetty.tty${i} default
  done
  
  # serial tty (for servers)
  ln -s /etc/openrc/init.d/agetty /etc/openrc/init.d/agetty.ttyS0
  /sbin/rc-update add agetty.ttyS0 default
  
  cp /etc/openrc/conf.d/agetty /etc/openrc/conf.d/agetty.ttyS0
  echo 'agetty_options="--noclear"' >> /etc/openrc/conf.d/agetty.ttyS0

=== Update boot parameters ===

Add the following to your boot parameters (via ///etc/lilo.conf// for lilo or ///etc/default/grub// for grub):
  init=/sbin/openrc-init

Regenerate boot configuration ('lilo -v' or 'grub-mkconfig -o /boot/grub/grub.cfg').

=== Enable boot logging ===

The main configuration file for OpenRC is ///etc/openrc/rc.conf//, and contains various options.

A common option that could be changed is to enable boot logging by setting ''rc_logger="YES"'', this way any errors encountered via booting could be logged and examined later (default log location is ///var/log/rc.log//).

===== On reboot =====

On rebooting, one is booted to a command line with only the bare minimum of services enabled.

It may show a warning about deprecated support for ///etc/mtab// as a file, and how to correct it:
  # cp /etc/mtab /etc/mtab.bkp
  # ln -snf /proc/self/mounts /etc/mtab
  
It may also complain about missing ///etc/sysctl.conf// file which can be created as:

  # touch /etc/sysctl.conf

==== Enabling some services ====

Services can be enabled as:

  # rc-service add <service> <runlevel>

They can be disabled as:

  # rc-service del <service> <runlevel>

Some common services that could be enabled:

  # rc-update add dbus default
  # rc-update add sysklogd default
  # rc-update add dcron default
  # rc-update add alsasound boot  # for desktop
  # rc-update add consolekit default  # for desktop
  # rc-update add sshd default  # for server

Enabled services in current runlevel can be queried with:
  $ rc-status

Enabled services across all runlevels can be queried with:
  $ rc-update

Some services that are enabled by default for the **sysinit** runlevel include udev and udev-postmount.

Users who use dmcrypt, lvm, or mdraid could add the following services respectively to the **boot** runlevel:

  # rc-update add dmcrypt boot        # dmcrypt
  # rc-update add device-mapper boot  # lvm
  # rc-update add lvm boot            # lvm
  # rc-update add mdraid boot         # mdraid

=== Network ===

If using ethernet via DHCP, the **dhcpcd** service could be enabled:
  # rc-update add dhcpcd default

If using wifi with laptops the **NetworkManager** or **wicd** service could be enabled. The combination of dhcpcd and wpa_supplicant (along with a frontend like wpa_gui or wpa_cli) could also be used as a lightweight alternative.

A static network can be configured by editing ///etc/openrc/conf.d/network//.

=== Display manager ===

To boot to a graphical display manager, ///etc/openrc/conf.d/xdm// can be edited to specify the display manager, and the xdm service could be enabled:

  # rc-update add xdm default

If using a laptop, the **acpid** service could be enabled as well.

=== Migrating existing enabled services ===

To check existing enabled services, following code could be used:


  for file in /etc/rc.d/*; do
    if [ -x "${file}" ]; then
      echo "enabled ${file}"
    fi
  done

For these services corresponding OpenRC services could be enabled, for example:

  # rc-update add acpid default
  # rc-update add cgmanager default
  # rc-update add gpm default
  ...

All services present can be queried via:

  $ rc-update -v

====== Configuration ======

OpenRC services are present in the ///etc/openrc/init.d// folder, and corresponding configuration files are present in ///etc/openrc/conf.d//

Some common configuration files include:

  /etc/openrc/conf.d/modules    # modules to be loaded at boot
  /etc/openrc/conf.d/hostname   # hostname of the system
  /etc/openrc/conf.d/keymaps    # console keymap

===== Service management =====

Services can be started/stopped/restarted as:

  # rc-service <service> <action>

For example,

  # rc-service sshd start

  
===== Shutdown/reboot =====

To shutdown or reboot, one will need to use **openrc-shutdown**. To shutdown from a desktop environment using ConsoleKit2, check out this [[https://github.com/ConsoleKit2/ConsoleKit2/pull/113|PR]].

==== Note ====

The **ck-system-stop** and **ck-system-restart** files in the [[https://github.com/ConsoleKit2/ConsoleKit2/pull/113|PR]] can be saved to ///usr/local/sbin/poweroff// and ///usr/local/sbin/reboot// respectively. This allows using the **poweroff** and **reboot** commands like before.

====== Troubleshooting ======

At the moment only a subset of the included services have been tested, so some of them may not run correctly.

If some service does not work, try the system provided one in ///etc/rc.d// (if available).

==== mysqld ====

Try adding the following lines to ///etc/my.cnf//

  [mysqld]
  user = mysql
  basedir = /usr
  datadir = /var/lib/mysql
  pid-file = /run/mysql/mysql.pid
  socket = /var/run/mysql/mysql.sock

==== Dealing with crashed services ====

Sometimes openrc reports a service's status as "crashed". The process may have died or its pid file disappeared/changed.

If one tries to start a crashed service, `rc-service` reports:

  * WARNING: <service> has already been started

So one tries to stop it before starting again.

However in some situations, the service does not stop. This leads to a deadlock where one can neither stop the service nor start it. For such cases:

  # rc-service <service> zap
  * Manually resetting <service> to stopped state

**zap** resets the service state, allowing us to start it again.

===== openrc-init =====

Since version **0.25**, openrc provides //openrc-init// which can be used to boot the system.

This allows switching between OpenRC and other init systems, for example sysvinit, just by changing boot parameters.

For more info, check out the [[https://wiki.gentoo.org/wiki/OpenRC#openrc-init|Gentoo wiki]].

===== Migrating from /etc/init.d to /etc/openrc/init.d =====

OpenRC 0.39+, as shipped via SBo, changes the service and configuration directory to ///etc/openrc// instead of ///etc//.

This is being done to maintain greater compatibility with a vanilla Slackware install.

Existing services will need to be migrated, details below on how it can be done.

=== 1. Install openrc-0.39.2 and openrc-services-20181107 ===

These packages ship the configuration and service files in ///etc/openrc//.

=== 2. Migrate existing services ===

This involves 4 steps:

  # migrate existing services
  for service in /etc/init.d/*; do
    svcname=$(basename "$service")
    if [ ! -e "/etc/openrc/init.d/${svcname}" ]; then
      if [ -f "/etc/init.d/${svcname}" ] && grep -q openrc "/etc/init.d/${svcname}"; then
        cp -v "/etc/init.d/${svcname}" "/etc/openrc/init.d/${svcname}"
      elif [ -L "/etc/init.d/${svcname}" ]; then
        # check if symlink is of a service
        service_target=$(readlink -f "$service")
        service_target_name=$(basename "$service_target")
        if [ $(dirname "$service_target") = "/etc/init.d" ]; then
          ln -sv "/etc/openrc/init.d/${service_target_name}" "/etc/openrc/init.d/${svcname}"
        fi
      fi
    fi
  done
  
  # enable existing services
  for runlevel in /etc/runlevels/*; do
    for service in ${runlevel}/*; do
      svcname=$(basename "$service")
      rvlname=$(basename "$runlevel")
      if [ ! -e /etc/openrc/runlevels/${rvlname}/${svcname} ] && [ -e /etc/openrc/init.d/${svcname} ]; then
        ln -sv /etc/openrc/init.d/${svcname} /etc/openrc/runlevels/${rvlname}/${svcname}
      fi
    done
  done
  
  # check config changes
  for file in /etc/conf.d/*; do
    filename=$(basename "$file")
    extension="${filename##*.}"
    if [ "$extension" = orig ] || [ "$extension" == new ]; then
      continue  # dont need to check extra
    fi
    if [ -e "/etc/conf.d/${filename}" ] && [ -e "/etc/openrc/conf.d/${filename}" ]; then
      diff -Nupr "/etc/conf.d/${filename}" "/etc/openrc/conf.d/${filename}"
    fi
  done
  # main config file
  diff -Nupr /etc/rc.conf /etc/openrc/rc.conf
  
  # check local.d changes
  for file in /etc/local.d/*; do
    filename=$(basename "$file")
    if [ ! -e "/etc/openrc/local.d/${filename}" ]; then
      cp -v "/etc/local.d/${filename}" "/etc/openrc/local.d/${filename}"
    elif [ -e "/etc/local.d/${filename}" ] && [ -e "/etc/openrc/local.d/${filename}" ]; then
      # show changes
      diff -Nupr "/etc/local.d/${filename}" "/etc/openrc/local.d/${filename}"
    fi
  done

Config changes found above can be updated by hand or copy pasted in new location.

=== 3. Check and reboot ===

Verify if ''rc-status'' is showing all services (it may show them as stopped).

Reboot and check whether things are working expected, make changes as necessary.

The old files and folders can be renamed (or removed).

  mv /etc/init.d /etc/init.d-openrc-bkp
  mv /etc/conf.d /etc/conf.d-openrc-bkp
  mv /etc/local.d /etc/local.d-openrc-bkp
  mv /etc/runlevels /etc/runlevels-openrc-bkp
  mv /etc/rc.conf /etc/rc.conf-openrc.bkp

Finally, any changes done to the default Slackware system can be reverted:

  mv /etc/init.d-bkp /etc/init.d

====== See Also ======

[[https://en.wikipedia.org/wiki/OpenRC|Wikipedia]]

[[https://wiki.gentoo.org/wiki/OpenRC|Gentoo Wiki]]

[[https://github.com/OpenRC/openrc/|Github]]

[[https://github.com/OpenRC/openrc/blob/master/user-guide.md|User guide]]

[[https://www.linuxquestions.org/questions/slackware-14/using-openrc-on-slackware-4175542567/|LQ thread]]

[[https://gitlab.com/aadityabagga/openrc-services|openrc-services repo]]


====== Sources ======
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* Originally written by [[wiki:user:aaditya | Aaditya]]
<!-- * Contributions by [[wiki:user:yyy | User Y]] -->

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