OpenRC

OpenRC

Original author(s)	Roy Marples
Developer(s)	OpenRC Developers
Initial release	5 April 2007 (2007-04-05)
Stable release	0.22.4 / 18 November 2016 (2016-11-18)
Repository	github.com/OpenRC/openrc
Written in	C
Operating system	Linux, FreeBSD, NetBSD
Size	~900 KB
Type	Init daemon
License	2-clause BSD license
Website	www.gentoo.org/proj/en/base/openrc/

On Unix-like systems, OpenRC is a dependency-based init system that works with the system-provided init program, normally /sbin/init; however, it is not a replacement for /sbin/init.

OpenRC is the default init system of Gentoo, Alpine Linux and other Linux distributions, which means that the software packages and daemons of those distributions support it, coming with or using the available scripts. Next to Linux OpenRC can also be used on different BSD systems. Its creator is a NetBSD developer, who started the Gentoo/FreeBSD project.

OpenRC provides the following features:

• Portable to non-Linux
• Parallel service startup (optional, in development)
• Dependency based boot-up
• Process segregation through cgroups
• Per-service resource limits (ulimit)
• Separation of code and configuration (init.d / conf.d)
• Easily extensible startup scripts customizable by users
• Ability to include an unlimited variety of commands beyond basic "start, stop, and status"
• Stateful init scripts (is it started already?)
• Complex init scripts to start multiple components (Samba (smbd and nmbd), NFS (nfsd, portmap, etc.))
• Automatic dependency calculation and service ordering
• Proper integration into container/virtualization (Linux-VServer, OpenVZ, etc.)
• Proper modular architecture and separation of optional components (Cron, syslog)
• Expressive and flexible network handling (including VPN, bridges, etc.)
• Support for bare-metal bare-dependency servers
• Verbose debug mode

External links

• Official website
• OpenRC git repositories at gentoo.org and GitHub
• Init systems comparison: part 1 and part 2 (LWN.net)