[2024-feb-29] Sad news: Eric Layton aka Nocturnal Slacker aka vtel57 passed away on Feb 26th, shortly after hospitalization. He was one of our Wiki's most prominent admins. He will be missed.

Welcome to the Slackware Documentation Project

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision
Previous revision
howtos:slackware_admin:runit [2019/09/16 06:40 (UTC)] – Typos in Chapter 8 (runevels) are corrected chrisabelahowtos:slackware_admin:runit [2020/05/06 08:08 (UTC)] (current) – [Startup and Shutdown] chrisabela
Line 1: Line 1:
 ====== Runit ====== ====== Runit ======
  
-===== 1. Introduction =====+===== Introduction =====
  
 runit is a UNIX init scheme with service supervision. It is a cross-platform Unix init scheme with service supervision, a replacement for sysvinit, and other init schemes and supervision that are used with the traditional init. runit is compatible with djb's daemontools. runit is a UNIX init scheme with service supervision. It is a cross-platform Unix init scheme with service supervision, a replacement for sysvinit, and other init schemes and supervision that are used with the traditional init. runit is compatible with djb's daemontools.
Line 11: Line 11:
 To read on the benefits of runit, see here: http://smarden.org/runit/benefits.html To read on the benefits of runit, see here: http://smarden.org/runit/benefits.html
  
-Unless otherwise stated, all commands in this article are to be run by root.+//* Unless otherwise stated, all commands in this article are to be run by root.//
  
-===== 2. Use runit with traditional init =====+===== Use runit with traditional init (sysvinit) =====
  
 runit is not provided by Slackware, but a SlackBuild is maintained on https://slackbuilds.org/. It does not have any dependencies. runit is not provided by Slackware, but a SlackBuild is maintained on https://slackbuilds.org/. It does not have any dependencies.
Line 31: Line 31:
 </code> </code>
  
-For a typical Slackware-stlyle service, you can also edit ''/etc/rc.d/rc.local'' file+==== Starting via rc.local ==== 
 + 
 +For a typical Slackware-stlyle service, you can edit ''/etc/rc.d/rc.local'' file
  
 <code> <code>
Line 38: Line 40:
 fi fi
 </code> </code>
- 
-if you require it. 
  
 and then edit write ''/etc/rc.d/rc.local_shutdown'' and then edit write ''/etc/rc.d/rc.local_shutdown''
Line 59: Line 59:
 and reboot and reboot
  
-===== 3. Using runit with sysvinit and inittab =====+==== Starting via inittab (supervised) ====
  
 Remove the entries in ''/etc/rc.d/rc.local'' and ''/etc/rc.d/rc.local_shutdown'' described above.  Remove the entries in ''/etc/rc.d/rc.local'' and ''/etc/rc.d/rc.local_shutdown'' described above. 
Line 79: Line 79:
 or reboot  or reboot 
  
-===== 4. How to replace init with runit =====+===== How to replace init with runit ===== 
 + 
 +runit provides ''runit-init'' which can be used to boot up the system.
  
 If you followed the previous chapter, then stop runsvdir and reverse all the changes that you made on your system. If you followed the previous chapter, then stop runsvdir and reverse all the changes that you made on your system.
Line 186: Line 188:
 However, with the last alternative, be warned that if you had booted with the original init, the system may refuse to reboot, therefore boot from runit-init first.  However, with the last alternative, be warned that if you had booted with the original init, the system may refuse to reboot, therefore boot from runit-init first. 
  
-===== 5. Startup and Shutdown =====+==== Startup and Shutdown ====
  
-The traditional init reads ''/etc/inittab'' file to see how to run the system. It runs the ''/etc/rc.d/rc.S'' script and runs it. If set in the default runlevel 3, it follows it with ''/etc/rc.d/rc.M''. In runit the initialisation script is located in ''/etc/runit/1'' for all runlevels. By default ''/etc/runit/2'' is restricted to the TTY services. +The BSD style init scripts provided by Slackware are used to bring up the system. 
 + 
 +Initially the single user script ''/etc/rc.d/rc.S'' runs. If set in the default runlevel 3, it follows it with ''/etc/rc.d/rc.M''. In runit the initialisation script is located in ''/etc/runit/1'' for all runlevels. By default ''/etc/runit/2'' is restricted to the TTY services. 
  
 The script ''/etc/rc.d/rc.6'' is the rebooting script for the traditional init, while ''/etc/rc.d/rc.0'' (symlinked to the former) is the halting script. In runit, these scripts are called by ''/etc/runit/3'' The script ''/etc/rc.d/rc.6'' is the rebooting script for the traditional init, while ''/etc/rc.d/rc.0'' (symlinked to the former) is the halting script. In runit, these scripts are called by ''/etc/runit/3''
Line 217: Line 221:
 However consider that shutdown would not work for the original init. However consider that shutdown would not work for the original init.
  
-===== 6. runsv =====+===== runsv =====
  
 Although runit may replace init as the PID 1 daemon, there is not much benefit unless other services are migrated from Slackware's BSD style to runsv(8). While this is not a complicated task, some familiarisation with runit's characteristics is recommended and makes the task easier. This short example should help illustrate runsv to new users. Although runit may replace init as the PID 1 daemon, there is not much benefit unless other services are migrated from Slackware's BSD style to runsv(8). While this is not a complicated task, some familiarisation with runit's characteristics is recommended and makes the task easier. This short example should help illustrate runsv to new users.
Line 324: Line 328:
 Now bob can manage this service with the ''sv'' command. Note that in most cases, services should belong to root, and only to root. Now bob can manage this service with the ''sv'' command. Note that in most cases, services should belong to root, and only to root.
  
-===== 7.  Managing Services with sv =====+=====  Managing Services with sv =====
  
 To see the status of a supervised service use ''sv s <service_name>'', for example, To see the status of a supervised service use ''sv s <service_name>'', for example,
Line 344: Line 348:
 </code> </code>
  
-==== 7.1. Stop/Start/Restart ====+==== Stop/Start/Restart ====
  
 Start a service Start a service
Line 378: Line 382:
 Each of these will also return the status of the service upon exit. Each of these will also return the status of the service upon exit.
  
-==== 7.2. Enabling a service ====+==== Enabling a service ====
  
 Service directories are placed under ''/etc/sv/''. To enable a service in the current runlevel, create a symlink from it to ''/service''. Service directories are placed under ''/etc/sv/''. To enable a service in the current runlevel, create a symlink from it to ''/service''.
Line 388: Line 392:
 Once a service is linked it will always start on boot and restart if it stops (unless this is disabled). Once a service is linked it will always start on boot and restart if it stops (unless this is disabled).
  
-==== 7.3. Disabling a service ====+==== Disabling a service ====
  
 To disable a service in the current runlevel remove the symlink to its service directory from ''/service''. To disable a service in the current runlevel remove the symlink to its service directory from ''/service''.
Line 410: Line 414:
 </code> </code>
  
-==== 7.4. Dependencies ====+==== Dependencies ====
  
 Dependencies of service are supported by starting the dependent run script as follows: Dependencies of service are supported by starting the dependent run script as follows:
Line 422: Line 426:
 </code> </code>
  
-===== 8. Runlevels =====+==== Runlevels ====
  
 If you installed the slackbuild configuration files, you have two runlevels: default and single. The current runlevel is default. You can verify by looking under ''/etc/runit/runsvdir/,'' you will see that ''/etc/runit/runsvdir/current'' is a symbolic link ''/etc/runit/runsvdir/default/''. If you installed the slackbuild configuration files, you have two runlevels: default and single. The current runlevel is default. You can verify by looking under ''/etc/runit/runsvdir/,'' you will see that ''/etc/runit/runsvdir/current'' is a symbolic link ''/etc/runit/runsvdir/default/''.
Line 446: Line 450:
 You can edit the runsvdir line of ''/etc/runit/2'' to your requirements. You can edit the runsvdir line of ''/etc/runit/2'' to your requirements.
  
-===== 9. run scripts =====+===== Run scripts =====
  
 Only one executable can be called for a service (the last line) and it must be called by the ''exec'' command. There are some generic runit run scripts on the Internet and on other Linux distributions. Also, other Slackers may post them on publicly available repositories. The author of this article has placed his here: https://gitlab.com/chrisabela/runit_scripts_for_slackware Only one executable can be called for a service (the last line) and it must be called by the ''exec'' command. There are some generic runit run scripts on the Internet and on other Linux distributions. Also, other Slackers may post them on publicly available repositories. The author of this article has placed his here: https://gitlab.com/chrisabela/runit_scripts_for_slackware
 +
 +Another set of installable run scripts are available at [[https://slackbuilds.org/repository/14.2/system/runit-services/|SBo]].
  
 In direct contrast to Slackware's BSD style service scripts, runit run scripts must not must run in the foreground, otherwise runit would think that they have crashed and restart them. In direct contrast to Slackware's BSD style service scripts, runit run scripts must not must run in the foreground, otherwise runit would think that they have crashed and restart them.
Line 458: Line 464:
 </code> </code>
  
-Or you can use the ''pause'' command to keep the service alive. ''pause'' is a trivial command that will simply not exit, until it is killed (akin to tail -f /dev/null). A SlackBuild for ''pause'' is available at https://slackbuilds.org Then end the run script with:+Or you can use the ''pause'' command to keep the service alive. ''pause'' is a trivial command that will simply not exit, until it is killed (akin to tail -f /dev/null). A SlackBuild for ''pause'' is available at [[https://slackbuilds.org/repository/14.2/system/pause/|SBo]]. Then end the run script with:
  
 <code> <code>
Line 464: Line 470:
 </code> </code>
  
-===== 10. Migrating Services =====+===== Migrating Services =====
  
 It is suggested that services are migrated from stage 2 (which are still under the Slackware's BSD init scheme) to stage 3 carefully. Start from the bottom of ''/etc/rc.d/rc.M'' and work up. This means that you should start with any entries under ''/etc/rc.d/rc.local''  It is suggested that services are migrated from stage 2 (which are still under the Slackware's BSD init scheme) to stage 3 carefully. Start from the bottom of ''/etc/rc.d/rc.M'' and work up. This means that you should start with any entries under ''/etc/rc.d/rc.local'' 
Line 515: Line 521:
 It is stuggested to let ''udev'' under runit's stage 2, but you can setup its monitoring for stage 3.  It is stuggested to let ''udev'' under runit's stage 2, but you can setup its monitoring for stage 3. 
  
-===== 11. Sources ===== +===== Using runit-init with other init scripts ===== 
-  + 
-(1) http://smarden.org/runit/+==== OpenRC ==== 
 + 
 +Here ''runit-init'' is used for booting, which then transfers control to the OpenRC for things like mounting the filesystem, loading modules, running udev, etc. 
 + 
 +It requires a working OpenRC system. Check the [[howtos:general_admin:openrc]] page for instructions. 
 +The level 1 runit service uses the OpenRC ''boot'' and ''sysinit'' runlevels.
  
-(2) https://slackbuilds.org+The [[https://wiki.gentoo.org/wiki/Runit#Runit_as_the_init_system|gentoo wiki]] has more information, and [[https://gitlab.com/aadityabagga/runit-init-openrc|runit-init-openrc]] details how to install and set it up.
  
-(3) https://en.wikipedia.org/wiki/Init+==== void-runit ====
  
-(4) https://voidlinux.org/usage/runit/+Here the scripts provided by the [[https://github.com/void-linux/void-runit|void-runit]] project are used to mount the filesystem, load modules, etc.
  
-(5) https://www.youtube.com/watch?v=jiBlIhFxNJo+Currently this is the most independent way to setup runit.
  
-(6) http://kchard.github.io/runit-quickstart/+===== Sources =====
  
-(7) https://www.slackbook.org/beta/+  - http://smarden.org/runit/ 
 +  - https://en.wikipedia.org/wiki/Init 
 +  - https://voidlinux.org/usage/runit/ 
 +  - https://www.youtube.com/watch?v=jiBlIhFxNJo 
 +  - http://kchard.github.io/runit-quickstart/ 
 +  - https://www.slackbook.org/beta/ 
 +  - https://gitlab.com/chrisabela/runit_scripts_for_slackware 
 +  - https://github.com/aadityabagga/runit-services 
 +  - https://wiki.gentoo.org/wiki/Runit 
 +  - https://github.com/void-linux/void-runit
  
-(8) https://gitlab.com/chrisabela/runit_scripts_for_slackware+----
  
   * Written for Slackware 14.2 in December 2018   * Written for Slackware 14.2 in December 2018
 howtos:slackware_admin:runit ()