guix/gnu/services/admin.scm
Ludovic Courtès 254ea3f945
services: rottlog: Make extensible.
* gnu/services/admin.scm (rottlog-service-type)[compose, extend]: New
fields.
* doc/guix.texi (Log Rotation): Mention extension.
2017-06-12 23:34:14 +02:00

176 lines
6.7 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
;;; Copyright © 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of thye GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu services admin)
#:use-module (gnu packages admin)
#:use-module (gnu packages base)
#:use-module (gnu services)
#:use-module (gnu services mcron)
#:use-module (gnu services shepherd)
#:use-module (guix gexp)
#:use-module (guix packages)
#:use-module (guix records)
#:use-module (srfi srfi-1)
#:use-module (ice-9 vlist)
#:export (%default-rotations
%rotated-files
log-rotation
log-rotation?
log-rotation-frequency
log-rotation-files
log-rotation-options
log-rotation-post-rotate
rottlog-configuration
rottlog-configuration?
rottlog-service
rottlog-service-type))
;;; Commentary:
;;;
;;; This module implements configuration of rottlog by writing
;;; /etc/rottlog/{rc,hourly|daily|weekly}. Example usage
;;;
;;; (mcron-service)
;;; (service rottlog-service-type)
;;;
;;; Code:
(define-record-type* <log-rotation> log-rotation make-log-rotation
log-rotation?
(files log-rotation-files) ;list of strings
(frequency log-rotation-frequency ;symbol
(default 'weekly))
(post-rotate log-rotation-post-rotate ;#f | gexp
(default #f))
(options log-rotation-options ;list of strings
(default '())))
(define %rotated-files
;; Syslog files subject to rotation.
'("/var/log/messages" "/var/log/secure" "/var/log/maillog"))
(define %default-rotations
(list (log-rotation ;syslog files
(files %rotated-files)
;; Restart syslogd after rotation.
(options '("sharedscripts"))
(post-rotate #~(let ((pid (call-with-input-file "/var/run/syslog.pid"
read)))
(kill pid SIGHUP))))
(log-rotation
(files '("/var/log/shepherd.log" "/var/log/guix-daemon.log")))))
(define (log-rotation->config rotation)
"Return a string-valued gexp representing the rottlog configuration snippet
for ROTATION."
(define post-rotate
(let ((post (log-rotation-post-rotate rotation)))
(and post
(program-file "rottlog-post-rotate.scm" post))))
#~(let ((post #$post-rotate))
(string-append (string-join '#$(log-rotation-files rotation) ",")
" {"
#$(string-join (log-rotation-options rotation)
"\n " 'prefix)
(if post
(string-append "\n postrotate\n " post
"\n endscript\n")
"")
"\n}\n")))
(define (log-rotations->/etc-entries rotations)
"Return the list of /etc entries for ROTATIONS, a list of <log-rotation>."
(define (frequency-file frequency rotations)
(computed-file (string-append "rottlog." (symbol->string frequency))
#~(call-with-output-file #$output
(lambda (port)
(for-each (lambda (str)
(display str port))
(list #$@(map log-rotation->config
rotations)))))))
(let* ((frequencies (delete-duplicates
(map log-rotation-frequency rotations)))
(table (fold (lambda (rotation table)
(vhash-consq (log-rotation-frequency rotation)
rotation table))
vlist-null
rotations)))
(map (lambda (frequency)
`(,(symbol->string frequency)
,(frequency-file frequency
(vhash-foldq* cons '() frequency table))))
frequencies)))
(define (default-jobs rottlog)
(list #~(job '(next-hour '(0)) ;midnight
(lambda ()
(system* #$(file-append rottlog "/sbin/rottlog"))))
#~(job '(next-hour '(12)) ;noon
(lambda ()
(system* #$(file-append rottlog "/sbin/rottlog"))))))
(define-record-type* <rottlog-configuration>
rottlog-configuration make-rottlog-configuration
rottlog-configuration?
(rottlog rottlog-rottlog ;package
(default rottlog))
(rc-file rottlog-rc-file ;file-like
(default (file-append rottlog "/etc/rc")))
(rotations rottlog-rotations ;list of <log-rotation>
(default %default-rotations))
(jobs rottlog-jobs ;list of <mcron-job>
(default #f)))
(define (rottlog-etc config)
`(("rottlog"
,(file-union "rottlog"
(cons `("rc" ,(rottlog-rc-file config))
(log-rotations->/etc-entries
(rottlog-rotations config)))))))
(define (rottlog-jobs-or-default config)
(or (rottlog-jobs config)
(default-jobs (rottlog-rottlog config))))
(define rottlog-service-type
(service-type
(name 'rottlog)
(extensions (list (service-extension etc-service-type rottlog-etc)
(service-extension mcron-service-type
rottlog-jobs-or-default)
;; Add Rottlog to the global profile so users can access
;; the documentation.
(service-extension profile-service-type
(compose list rottlog-rottlog))))
(compose concatenate)
(extend (lambda (config rotations)
(rottlog-configuration
(inherit config)
(rotations (append (rottlog-rotations config)
rotations)))))
(default-value (rottlog-configuration))))
;;; admin.scm ends here