gnu: Add rsync service.

* doc/guix.texi (Networking Services): Add rsync service documentation.
* gnu/services/rsync.scm (<rsync-configuration>): New file.
* gnu/tests/rsync.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add new files.

Signed-off-by: Christopher Baines <mail@cbaines.net>

1 files changed, 172 insertions, 0 deletions

diff --git a/gnu/services/rsync.scm b/gnu/services/rsync.scm
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index 0000000000..621e6c46d4
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+++ b/gnu/services/rsync.scm
@@ -0,0 +1,172 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2017 Oleg Pykhalov <go.wigust@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 services)
+  #:use-module (gnu services base)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu system shadow)
+  #:use-module (gnu packages rsync)
+  #:use-module (gnu packages admin)
+  #:use-module (guix records)
+  #:use-module (guix gexp)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:use-module (ice-9 match)
+  #:export (rsync-configuration
+            rsync-configuration?
+            rsync-service-type))
+
+;;;; Commentary:
+;;;
+;;; This module implements a service that to run instance of Rsync,
+;;; files synchronization tool.
+;;;
+;;;; Code:
+
+(define-record-type* <rsync-configuration>
+  rsync-configuration
+  make-rsync-configuration
+  rsync-configuration?
+  (package       rsync-configuration-package              ; package
+                 (default rsync))
+  (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
+                 (default #t))
+  (share-path    rsync-configuration-share-path           ; string
+                 (default "/srv/rsyncd"))
+  (share-comment rsync-configuration-share-comment        ; string
+                 (default "Rsync share"))
+  (read-only?    rsync-configuration-read-only?           ; boolean
+                 (default #f))
+  (timeout       rsync-configuration-timeout              ; integer
+                 (default 300))
+  (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")))
+
+(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 #~(string-append #$shadow "/sbin/nologin"))))))
+
+(define (rsync-activation config)
+  "Return the activation GEXP for CONFIG."
+  (with-imported-modules '((guix build utils))
+    #~(begin
+        (let ((share-directory  #$(rsync-configuration-share-path config))
+              (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 #$(rsync-configuration-pid-file config)))
+          (and=> share-directory mkdir-p)
+          (chown share-directory
+                 (passwd:uid user)
+                 (group:gid group))))))
+
+(define rsync-config-file
+  ;; Return the rsync configuration file corresponding to CONFIG.
+  (match-lambda
+    (($ <rsync-configuration> package port-number pid-file lock-file log-file
+                              use-chroot? share-path share-comment read-only?
+                              timeout user group uid gid)
+     (if (not (string=? user "root"))
+         (cond
+          ((<= port-number 1024)
+           (error (string-append "rsync-service: to run on port "
+                                 (number->string port-number)
+                                 ", user must be root.")))
+          (use-chroot?
+           (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."))))
+     (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"
+      "port = " (number->string port-number) "\n"
+      "use chroot = " (if use-chroot? "true" "false") "\n"
+      (if uid (string-append "uid = " uid "\n") "")
+      "gid = " (if gid gid "nogroup") "\n" ; no group nobody
+      "\n"
+      "[files]\n"
+      "path = " share-path "\n"
+      "comment = " share-comment "\n"
+      "read only = " (if read-only? "true" "false") "\n"
+      "timeout = " (number->string timeout) "\n"))))
+
+(define (rsync-shepherd-service config)
+  "Return a <shepherd-service> for rsync with CONFIG."
+  (let* ((rsync       (rsync-configuration-package config))
+         (pid-file    (rsync-configuration-pid-file config))
+         (port-number (rsync-configuration-port-number config))
+         (user        (rsync-configuration-user config))
+         (group       (rsync-configuration-group config)))
+    (list (shepherd-service
+           (provision '(rsync))
+           (documentation "Run rsync daemon.")
+           (start #~(make-forkexec-constructor
+                     (list (string-append #$rsync "/bin/rsync")
+                           "--config" #$(rsync-config-file config)
+                           "--daemon")
+                     #:pid-file #$pid-file
+                     #:user #$user
+                     #:group #$group))
+           (stop #~(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))))