services: Add rottlog.

* gnu/services/admin.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (Log Rotation): New node.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 83 insertions, 1 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index f5bbb92c7c..b670823753 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -26,7 +26,8 @@ Copyright @copyright{} 2016 Ben Woodcroft@*
 Copyright @copyright{} 2016 Chris Marusich@*
 Copyright @copyright{} 2016 Efraim Flashner@*
 Copyright @copyright{} 2016 John Darrington@*
-Copyright @copyright{} 2016 ng0
+Copyright @copyright{} 2016 ng0@*
+Copyright @copyright{} 2016 Jan Nieuwenhuizen
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -213,6 +214,7 @@ Services
 
 * Base Services::               Essential system services.
 * Scheduled Job Execution::     The mcron service.
+* Log Rotation::                The rottlog service.
 * Networking Services::         Network setup, SSH daemon, etc.
 * X Window::                    Graphical display.
 * Desktop Services::            D-Bus and desktop services.
@@ -7581,6 +7583,7 @@ declaration.
 @menu
 * Base Services::               Essential system services.
 * Scheduled Job Execution::     The mcron service.
+* Log Rotation::                The rottlog service.
 * Networking Services::         Network setup, SSH daemon, etc.
 * X Window::                    Graphical display.
 * Desktop Services::            D-Bus and desktop services.
@@ -8055,6 +8058,85 @@ specifications,, mcron, GNU@tie{}mcron}).
 @end deftp
 
 
+@node Log Rotation
+@subsubsection Log Rotation
+
+@cindex rottlog
+@cindex log rotation
+Log files such as those found in @file{/var/log} tend to grow endlessly,
+so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
+their contents in separate files, possibly compressed.  The @code{(gnu
+services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
+log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
+
+The example below defines an operating system that provides log rotation
+with the default settings.
+
+@lisp
+(use-modules (guix) (gnu))
+(use-service-modules admin mcron)
+(use-package-modules base idutils)
+
+(operating-system
+  ;; @dots{}
+  (services (cons* (mcron-service)
+                   (service rottlog-service-type (rottlog-configuration)) 
+                   %base-services)))
+@end lisp
+
+@defvr {Scheme Variable} rottlog-service-type
+This is the type of the Rottlog service, whose value is a
+@code{rottlog-configuration} object.
+
+This service type can define mcron jobs (@pxref{Scheduled Job
+Execution}) to run the rottlog service.
+@end defvr
+
+@deftp {Data Type} rottlog-configuration
+Data type representing the configuration of rottlog.
+
+@table @asis
+@item @code{rottlog} (default: @code{rottlog})
+The Rottlog package to use.
+
+@item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
+The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
+rottlog, GNU Rot[t]log Manual}).
+
+@item @code{periodic-rotations} (default: @code{`(("weekly" %default-rotatations))})
+A list of Rottlog period-name/period-config tuples.
+
+For example, taking an example from the Rottlog manual (@pxref{Period
+Related File Examples,,, rottlog, GNU Rot[t]log Manual}), a valid tuple
+might be:
+
+@example
+("daily" ,(plain-file "daily"
+                      "\
+     /var/log/apache/* @{
+        storedir apache-archives
+        rotate 6
+        notifempty
+        nocompress
+     @}"))
+@end example
+
+@item @code{jobs}
+This is a list of gexps where each gexp corresponds to an mcron job
+specification (@pxref{Scheduled Job Execution}).
+@end table
+@end deftp
+
+@defvr {Scheme Variable} %default-rotations
+Specifies weekly rotation of @var{%rotated-files} and
+@code{"/var/log/shepherd.log"}.
+@end defvr
+
+@defvr {Scheme Variable} %rotated-files
+The list of syslog-controlled files to be rotated.  By default it is:
+@code{'("/var/log/messages" "/var/log/secure")}.
+@end defvr
+
 @node Networking Services
 @subsubsection Networking Services