;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Oleg Pykhalov <go.wigust@gmail.com>
;;; Copyright © 2021, 2023 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2023 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;;
;;; 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 the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu services rsync)
#:use-module ((gnu build linux-container) #:select (%namespaces))
#:use-module (gnu services)
#:use-module (gnu services base)
#:use-module (gnu services shepherd)
#:autoload (gnu system file-systems) (file-system-mapping)
#:use-module (gnu system shadow)
#:use-module (gnu packages admin)
#:use-module (gnu packages linux)
#:use-module (gnu packages rsync)
#:use-module (guix records)
#:use-module (guix gexp)
#:use-module (guix diagnostics)
#:use-module (guix i18n)
#:use-module (guix least-authority)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (ice-9 match)
#:export (rsync-configuration
rsync-configuration?
rsync-configuration-modules
rsync-module
rsync-module?
rsync-module-name
rsync-module-file-name
rsync-module-comment
rsync-module-read-only
rsync-module-timeout
rsync-service-type))
;;;; Commentary:
;;;
;;; This module implements a service that to run instance of Rsync,
;;; files synchronization tool.
;;;
;;;; Code:
(define-with-syntax-properties (warn-share-field-deprecation (value properties))
(unless (unspecified? value)
(warning (source-properties->location properties)
(G_ "the 'share-path' and 'share-comment' fields is deprecated, \
please use 'modules' instead~%")))
value)
(define-record-type* <rsync-configuration>
rsync-configuration
make-rsync-configuration
rsync-configuration?
(package rsync-configuration-package ; file-like
(default rsync))
(address rsync-configuration-address ; string | #f
(default #f))
(port-number rsync-configuration-port-number ; integer
(default 873))
(pid-file rsync-configuration-pid-file ; string
(default "/var/run/rsyncd/rsyncd.pid"))
(lock-file rsync-configuration-lock-file ; string
(default "/var/run/rsyncd/rsyncd.lock"))
(log-file rsync-configuration-log-file ; string
(default "/var/log/rsyncd.log"))
(use-chroot? rsync-configuration-use-chroot? ; boolean
(sanitize warn-share-field-deprecation)
(default *unspecified*))
(modules rsync-configuration-actual-modules ;list of <rsync-module>
(default %default-modules)) ;TODO: eventually remove default
(share-path rsync-configuration-share-path ; string
(sanitize warn-share-field-deprecation)
(default *unspecified*))
(share-comment rsync-configuration-share-comment ; string
(sanitize warn-share-field-deprecation)
(default *unspecified*))
(read-only? rsync-configuration-read-only? ; boolean
(sanitize warn-share-field-deprecation)
(default *unspecified*))
(timeout rsync-configuration-timeout ; integer
(sanitize warn-share-field-deprecation)
(default *unspecified*))
(user rsync-configuration-user ; string
(default "root"))
(group rsync-configuration-group ; string
(default "root"))
(uid rsync-configuration-uid ; string
(default "rsyncd"))
(gid rsync-configuration-gid ; string
(default "rsyncd")))
;; Rsync "module": a directory exported the rsync protocol.
(define-record-type* <rsync-module>
rsync-module make-rsync-module
rsync-module?
(name rsync-module-name) ;string
(file-name rsync-module-file-name) ;string
(comment rsync-module-comment ;string
(default ""))
(read-only? rsync-module-read-only? ;boolean
(default #t))
(chroot? rsync-module-chroot? ;boolean
(default #t))
(timeout rsync-module-timeout ;integer
(default 300)))
(define %default-modules
;; Default modules, provided for backward compatibility.
(list (rsync-module (name "files")
(file-name "/srv/rsyncd")
(comment "Rsync share")
(read-only? #f)))) ;yes, that was the default
(define (rsync-configuration-modules config)
(match-record config <rsync-configuration>
(modules
share-path share-comment use-chroot? read-only? timeout) ;deprecated
(if (unspecified? share-path)
(rsync-configuration-actual-modules config)
(list (rsync-module ;backward compatibility
(name "files")
(file-name share-path)
(comment "Rsync share")
(chroot?
(if (unspecified? use-chroot?) #t use-chroot?))
(read-only?
(if (unspecified? read-only?) #f read-only?))
(timeout
(if (unspecified? timeout) 300 timeout)))))))
(define (rsync-account config)
"Return the user accounts and user groups for CONFIG."
(let ((rsync-user (if (rsync-configuration-uid config)
(rsync-configuration-uid config)
(rsync-configuration-user config)))
(rsync-group (if (rsync-configuration-gid config)
(rsync-configuration-gid config)
(rsync-configuration-group config))))
(list (user-group (name rsync-group) (system? #t))
(user-account
(name rsync-user)
(system? #t)
(group rsync-group)
(comment "rsyncd privilege separation user")
(home-directory (string-append "/var/run/"
rsync-user))
(shell (file-append shadow "/sbin/nologin"))))))
(define (rsync-activation config)
"Return the activation GEXP for CONFIG."
(with-imported-modules '((guix build utils))
#~(begin
(let ((user (getpw (if #$(rsync-configuration-uid config)
#$(rsync-configuration-uid config)
#$(rsync-configuration-user config))))
(group (getpw (if #$(rsync-configuration-gid config)
#$(rsync-configuration-gid config)
#$(rsync-configuration-group config)))))
(mkdir-p (dirname #$(rsync-configuration-pid-file config)))
(for-each (lambda (directory)
(mkdir-p directory)
(chown directory (passwd:uid user) (group:gid group)))
'#$(map rsync-module-file-name
(rsync-configuration-modules config)))))))
(define (rsync-config-file config)
;; Return the rsync configuration file corresponding to CONFIG.
(define (module-config module)
(match-record module <rsync-module>
(name file-name comment chroot? read-only? timeout)
(list "[" name "]\n"
" path = " file-name "\n"
" use chroot = " (if chroot? "true" "false") "\n"
" comment = " comment "\n"
" read only = " (if read-only? "true" "false") "\n"
" timeout = " (number->string timeout) "\n")))
(define modules
(rsync-configuration-modules config))
(match-record config <rsync-configuration>
(package address port-number pid-file lock-file log-file
user group uid gid)
(unless (string=? user "root")
(cond
((<= port-number 1024)
(error (string-append "rsync-service: to run on port "
(number->string port-number)
", user must be root.")))
((find rsync-module-chroot? modules)
(error (string-append "rsync-service: to run in a chroot"
", user must be root.")))
(uid
(error "rsync-service: to use uid, user must be root."))
(gid
(error "rsync-service: to use gid, user must be root."))))
(apply mixed-text-file "rsync.conf"
"# Generated by 'rsync-service'.\n\n"
"pid file = " pid-file "\n"
"lock file = " lock-file "\n"
"log file = " log-file "\n"
(if address (string-append "address = " address "\n") "")
"port = " (number->string port-number) "\n"
(if uid (string-append "uid = " uid "\n") "")
"gid = " (if gid gid "nogroup") "\n" ; no group nobody
"\n\n"
(append-map module-config modules))))
(define (rsync-shepherd-service config)
"Return a <shepherd-service> for rsync with CONFIG."
;; XXX: Predicates copied from (gnu services ssh).
(define inetd-style?
#~(and (defined? 'make-inetd-constructor)
(not (string=? (@ (shepherd config) Version) "0.9.0"))))
(define ipv6-support?
#~(catch 'system-error
(lambda ()
(let ((sock (socket AF_INET6 SOCK_STREAM 0)))
(close-port sock)
#t))
(const #f)))
(define (module->file-system-mapping module)
"Return the <file-system-mapping> record corresponding to MODULE, an
<rsync-module> object."
(match-record module <rsync-module>
(file-name read-only?)
(file-system-mapping
(source file-name)
(target source)
(writable? (not read-only?)))))
(match-record config <rsync-configuration>
(package log-file modules pid-file port-number user group)
;; Run the rsync daemon in its own 'mnt' namespace, to guard against
;; change to mount points it may be serving.
(let* ((config-file (rsync-config-file config))
(rsync-command #~(list #$(least-authority-wrapper
(file-append rsync "/bin/rsync")
#:name "rsync"
#:namespaces (fold delq %namespaces
'(net user))
#:mappings
(append (list (file-system-mapping
(source "/var/run/rsyncd")
(target source)
(writable? #t))
(file-system-mapping
(source (dirname log-file))
(target source)
(writable? #t))
(file-system-mapping
(source config-file)
(target source)))
(map module->file-system-mapping
modules)))
"--config" #$config-file "--daemon")))
(list (shepherd-service
(provision '(rsync))
(documentation "Run rsync daemon.")
(actions (list (shepherd-configuration-action config-file)))
(start #~(if #$inetd-style?
(make-inetd-constructor
#$rsync-command
(cons (endpoint
(make-socket-address AF_INET INADDR_ANY
#$port-number))
(if #$ipv6-support?
(list
(endpoint
(make-socket-address AF_INET6 IN6ADDR_ANY
#$port-number)))
'()))
#:service-name-stem "rsync"
#:user #$user
#:group #$group)
(make-forkexec-constructor #$rsync-command
#:pid-file #$pid-file
#:user #$user
#:group #$group)))
(stop #~(if #$inetd-style?
(make-inetd-destructor)
(make-kill-destructor))))))))
(define rsync-service-type
(service-type
(name 'rsync)
(extensions
(list (service-extension shepherd-root-service-type rsync-shepherd-service)
(service-extension account-service-type rsync-account)
(service-extension activation-service-type rsync-activation)))
(default-value (rsync-configuration))
(description
"Run the rsync file copying tool in daemon mode. This allows remote hosts
to keep synchronized copies of the files exported by rsync.")))
