[bug#72398] [PATCH v3] services: Add readymedia-service-type.

[Fabio Natali via Guix-patches via <guix-patches@gnu.org>]

* gnu/services/upnp.scm: New file.
* gnu/local.mk: Add this.
* doc/guix.texi: Document this.

Change-Id: I80b02235ec36b7a1ea85fea98bdc9e08126b09a3
---
Hi,

Here's a short recap of how to test this.

Save this system definition in a file, e.g. '/tmp/config.scm'. Note the insecure
user credentials.

(use-modules (gnu))
(use-package-modules video)
(use-service-modules desktop upnp)

(define %test-user-account
  (user-account (name "test")
                (group "users")
                (supplementary-groups '("wheel"))
                (password (crypt "password" "foo"))))

(operating-system
  (host-name "host")
  (bootloader (bootloader-configuration
               (bootloader grub-bootloader)
               (targets '("/dev/vda"))))
  (file-systems (cons (file-system
                        (device "/dev/vda1")
                        (mount-point "/")
                        (type "ext4"))
                      %base-file-systems))
  (users (cons*
          %test-user-account
          %base-user-accounts))
  (sudoers-file (plain-file
                 "sudoers"
                 (string-append
                  (plain-file-content %sudoers-specification)
                  "%wheel ALL = NOPASSWD: ALL")))
  (packages (cons* vlc %base-packages))
  (services (cons*
             (service gnome-desktop-service-type)
             (service readymedia-service-type
                      (readymedia-configuration
                       (user %test-user-account)
                       (media-directories
                        (list
                         (readymedia-media-directory (path "/media/music")
                                                     (type 'A))))))
             %desktop-services)))

From within the Guix repository checkout, once the ReadyMedia service patch has
been applied, build and launch the VM with:

$(./pre-inst-env guix system vm \
    --share=/tmp/foo=/media/music \
    /tmp/config.scm) -m 2048 -smp 2

Log in as 'user'. Open a terminal and verify that the ReadyMedia service is
running with 'sudo herd status'.

Open VLC and follow these instructions
https://www.vlchelp.com/access-media-upnp-dlna/to verify that the ReadyMedia
service is running and that the 'foo.mp3' file can be played.

Open a browser and verify that the ReadyMedia web page is also reachable at
'http://127.0.0.1:8200'.

More comments in my previous email to this same thread.

Thanks, cheers, Fabio.


 doc/guix.texi         | 107 +++++++++++++++++++++
 gnu/local.mk          |   1 +
 gnu/services/upnp.scm | 211 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 319 insertions(+)
 create mode 100644 gnu/services/upnp.scm

diff --git a/doc/guix.texi b/doc/guix.texi
index fcaf6b3fbb..ddc997b6bf 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -129,6 +129,7 @@
 Copyright @copyright{} 2024 Richard Sent@*
 Copyright @copyright{} 2024 Dariqq@*
 Copyright @copyright{} 2024 Denis 'GNUtoo' Carikli@*
+Copyright @copyright{} 2024 Fabio Natali@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -41605,6 +41606,112 @@ Miscellaneous Services
 
 @end deftp
 
+@c %end of fragment
+
+@cindex DLNA/UPnP
+@subsubheading DLNA/UPnP Services
+
+The @code{(gnu services upnp)} module offers services related to the
+DLNA and UPnP-VA networking protocols.  For now, it provides the
+@code{readymedia-service-type}.
+
+@uref{https://sourceforge.net/projects/minidlna/, ReadyMedia}
+(formerly known as MiniDLNA) is a DLNA/UPnP-AV media server.  The
+project's daemon, @code{minidlnad}, can serve media files (audio,
+pictures, and video) to DLNA/UPnP-AV clients available in the network.
+
+@code{readymedia-service-type} is a Guix service that wraps around
+ReadyMedia's @code{minidlnad}.  For increased security, the service
+makes use of @code{least-authority-wrapper} which limits the resources
+that the daemon has access to.  The daemon runs as the
+@code{readymedia} unprivileged user, which is a member of the
+@code{readymedia} group.
+
+Consider the following configuration:
+
+@lisp
+(use-service-modules upnp @dots{})
+
+(operating-system
+  ;; @dots{}
+  (services
+   (list
+    (service readymedia-service-type
+             (readymedia-configuration
+              (media-directoriess
+               (list
+                (readymedia-media-directory (path "/media/audio")
+                                            (type 'A))
+                (readymedia-media-directory (path "/media/video")
+                                            (type 'V))
+                (readymedia-media-directory (path "/media/misc"))))
+              (extra-config '(("notify_interval" . 60)))))
+    ;; @dots{}
+    )))
+@end lisp
+
+This sets up the ReadyMedia daemon to serve files from the media
+folders specified in @code{media-directories}.  The
+@code{media-directories} field is mandatory.  All other fields (such
+as network ports and the server name) come with a predefined default
+and can be omitted.
+
+@c %start of fragment
+
+@deftp {Data Type} readymedia-configuration
+Available @code{readymedia-configuration} fields are:
+
+@table @asis
+@item @code{readymedia} (default: @code{readymedia}) (type: package)
+The ReadyMedia package to be used for the service.
+
+@item @code{friendly-name} (default: @code{#f}) (type: maybe-string)
+A custom name that will be displayed on connected clients.
+
+@item @code{media-directories} (type: list)
+The list of media folders to serve content from.  Each item is a
+@code{readymedia-media-directory}.
+
+@item @code{cache-directory} (default: @code{"/var/cache/readymedia"}) (type: string)
+A folder for ReadyMedia's cache files.  If not existing already, the
+folder will be created as part of the service activation and the
+ReadyMedia user will be assigned ownership.
+
+@item @code{log-directory} (default: @code{"/var/log/readymedia"}) (type: string)
+A folder for ReadyMedia's log files.  If not existing already, the
+folder will be created as part of the service activation and the
+ReadyMedia user will be assigned ownership.
+
+@item @code{port} (default: @code{#f}) (type: maybe-integer)
+A custom port that the service will be listening on.
+
+@item @code{extra-config} (default: @code{'()}) (type: alist)
+An association list of further options, as accepted by ReadyMedia.
+
+@end table
+
+@end deftp
+
+@c %end of fragment
+
+@c %start of fragment
+
+@deftp {Data Type} readymedia-media-directory
+A @code{media-directories} entry includes a @code{path} and,
+optionally, a media type string.
+
+@table @asis
+@item @code{path} (type: string)
+The media folder location.
+
+@item @code{type} (default: @code{#f}) (type: maybe-symbol)
+Valid media types are @code{'A} for audio, @code{'P} for pictures,
+@code{'V} for video, and a combination of those individual symbols for
+mixed types.  False means no type specified.
+
+@end table
+
+@end deftp
 
 @c %end of fragment
 
diff --git a/gnu/local.mk b/gnu/local.mk
index 11dff1c6c4..336ca14bbe 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -752,6 +752,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/services/syncthing.scm			\
   %D%/services/sysctl.scm			\
   %D%/services/telephony.scm			\
+  %D%/services/upnp.scm				\
   %D%/services/version-control.scm              \
   %D%/services/vnc.scm				\
   %D%/services/vpn.scm				\
diff --git a/gnu/services/upnp.scm b/gnu/services/upnp.scm
new file mode 100644
index 0000000000..5f8e5ac8b0
--- /dev/null
+++ b/gnu/services/upnp.scm
@@ -0,0 +1,211 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2024 Fabio Natali <me@fabionatali.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 upnp)
+  #:use-module (gnu build linux-container)
+  #:use-module (gnu packages admin)
+  #:use-module (gnu packages upnp)
+  #:use-module (gnu services admin)
+  #:use-module (gnu services base)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu services)
+  #:use-module (gnu system file-systems)
+  #:use-module (gnu system shadow)
+  #:use-module (guix gexp)
+  #:use-module (guix least-authority)
+  #:use-module (guix records)
+  #:use-module (ice-9 match)
+  #:export (readymedia-configuration
+            readymedia-configuration-cache-directory
+            readymedia-configuration-extra-config
+            readymedia-configuration-friendly-name
+            readymedia-configuration-group
+            readymedia-configuration-log-directory
+            readymedia-configuration-media-directories
+            readymedia-configuration-port
+            readymedia-configuration-readymedia
+            readymedia-configuration-user
+            readymedia-configuration?
+            readymedia-media-directory
+            readymedia-media-directory-path
+            readymedia-media-directory-type
+            readymedia-media-directory?
+            readymedia-service-type))
+
+;;; Commentary:
+;;;
+;;; UPnP services.
+;;;
+;;; Code:
+
+(define %readymedia-user-group
+  (user-group
+   (name "readymedia")
+   (system? #t)))
+
+(define %readymedia-user-account
+  (user-account
+   (name "readymedia")
+   (group "readymedia")
+   (system? #t)
+   (comment "ReadyMedia/MiniDLNA daemon user")
+   (home-directory "/var/empty")
+   (shell (file-append shadow "/sbin/nologin"))))
+
+(define-record-type* <readymedia-configuration>
+  readymedia-configuration make-readymedia-configuration
+  readymedia-configuration?
+  (readymedia readymedia-configuration-readymedia
+              (default readymedia))
+  (cache-directory readymedia-configuration-cache-directory
+             (default "/var/cache/readymedia"))
+  (log-directory readymedia-configuration-log-directory
+           (default "/var/log/readymedia"))
+  (friendly-name readymedia-configuration-friendly-name
+                 (default #f))
+  (media-directories readymedia-configuration-media-directories)
+  (port readymedia-configuration-port
+        (default #f))
+  (user readymedia-configuration-user
+        (default %readymedia-user-account))
+  (group readymedia-configuration-group
+         (default %readymedia-user-group))
+  (extra-config readymedia-configuration-extra-config
+                (default '())))
+
+;; READYMEDIA-MEDIA-DIR is a record that indicates path and media type of a
+;; media folder. Type can be false (no media type specified) or a symbol
+;; (e.g. 'A' for audio, 'V' for video, 'AV' for audio and video). The allowed
+;; individual types are 'A' for audio, 'P' for pictures, 'V' for video.
+(define-record-type* <readymedia-media-directory>
+  readymedia-media-directory make-readymedia-media-directory
+  readymedia-media-directory?
+  (path readymedia-media-directory-path)
+  (type readymedia-media-directory-type (default #f)))
+
+(define (readymedia-media-directory-type->string type)
+  "Convert a media-directory TYPE to a string."
+  (match type
+    (#f "")
+    (symbol (symbol->string type))))
+
+(define (readymedia-media-directory->string entry)
+  "Convert a media-directory ENTRY to a ReadyMedia/MiniDLNA media dir string."
+  (let ((type (readymedia-media-directory-type entry)))
+    (format #f
+            "media_dir=~a,~a"
+            (readymedia-media-directory-type->string type)
+            (readymedia-media-directory-path entry))))
+
+(define (readymedia-extra-config-entry->string entry)
+  "Convert a extra-config ENTRY to a ReadyMedia/MiniDLNA configuration string."
+  (let ((key (car entry))
+        (value (cdr entry)))
+    (format #f "~a=~a" key value)))
+
+(define (readymedia-configuration->config-file config)
+  "Return the ReadyMedia/MiniDLNA configuration file corresponding to CONFIG."
+  (let ((friendly-name (readymedia-configuration-friendly-name config))
+        (media-directories (readymedia-configuration-media-directories config))
+        (cache-directory (readymedia-configuration-cache-directory config))
+        (log-directory (readymedia-configuration-log-directory config))
+        (port (readymedia-configuration-port config))
+        (extra-config (readymedia-configuration-extra-config config)))
+    (mixed-text-file
+     "minidlna.conf"
+     "db_dir=" cache-directory "\n"
+     "log_dir=" log-directory "\n"
+     (if friendly-name (format #f "friendly_name=~a\n" friendly-name) "")
+     (if port (format #f "port=~a\n" port) "")
+     (string-join
+      (map readymedia-media-directory->string media-directories) "\n" 'suffix)
+     (string-join
+      (map readymedia-extra-config-entry->string extra-config) "\n" 'suffix))))
+
+(define (readymedia-shepherd-service config)
+  "Return a least-authority ReadyMedia/MiniDLNA Shepherd service."
+  (let* ((minidlna-conf (readymedia-configuration->config-file config))
+         (media-directories (readymedia-configuration-media-directories config))
+         (cache-directory (readymedia-configuration-cache-directory config))
+         (log-directory (readymedia-configuration-log-directory config))
+         (user (readymedia-configuration-user config))
+         (group (readymedia-configuration-group config))
+         (readymedia (least-authority-wrapper
+                      (file-append
+                       (readymedia-configuration-readymedia config)
+                       "/sbin/minidlnad")
+                      #:name "minidlna"
+                      #:mappings
+                      (cons* (file-system-mapping
+                              (source cache-directory)
+                              (target source)
+                              (writable? #t))
+                             (file-system-mapping
+                              (source log-directory)
+                              (target source)
+                              (writable? #t))
+                             (file-system-mapping
+                              (source minidlna-conf)
+                              (target source))
+                             (map
+                              (lambda (e)
+                                (file-system-mapping
+                                 (source (readymedia-media-directory-path e))
+                                 (target source)
+                                 (writable? #f)))
+                              media-directories))
+                      #:namespaces (delq 'net %namespaces))))
+    (list (shepherd-service
+           (documentation "Run the ReadyMedia/MiniDLNA daemon.")
+           (provision '(readymedia))
+           (requirement '(networking user-processes))
+           (start
+            #~(begin
+                (use-modules (gnu build activation))
+                (let* ((user-id (getpw #$(user-account-name user)))
+                       (dirs (list
+                              #$cache-directory
+                              #$log-directory
+                              #$@(map (lambda (e)
+                                        (readymedia-media-directory-path e))
+                                      media-directories)))
+                       (init-directory (lambda (d)
+                                         (unless (file-exists? d)
+                                           (mkdir-p/perms d user-id #o755)))))
+                  (for-each init-directory dirs))
+                (make-forkexec-constructor
+                 ;; "-S" is to daemonise minidlnad.
+                 (list #$readymedia "-f" #$minidlna-conf "-S")
+                 #:user #$(user-account-name user)
+                 #:group #$(user-group-name group))))
+           (stop #~(make-kill-destructor))))))
+
+(define (readymedia-account-service config)
+  (match-record config <readymedia-configuration>
+                (group user)
+                (list group user)))
+
+(define readymedia-service-type
+  (service-type
+   (name 'readymedia)
+   (extensions
+    (list
+     (service-extension shepherd-root-service-type readymedia-shepherd-service)
+     (service-extension account-service-type readymedia-account-service)))
+   (description
+    "Run @command{minidlnad}, the ReadyMedia/MiniDLNA media server.")))

base-commit: 2c7119b43bd44ee812ceaa2351bff9a8b623a920
-- 
2.45.2