[bug#69692] [PATCH] gnu: Add home-jellyfin-mpv-shim-service-type.

[bug#69692] [PATCH] gnu: Add home-jellyfin-mpv-shim-service-type.

[Ian Eure]

Split off from 67120.

* gnu/home/services/media.scm (home-jellyfin-mpv-shim-service-type): New variable.
* doc/guix.texi (Jellyfin Services): New section.
* doc/guix.texi (Kodi Services): Add subheading.

Change-Id: I037ab0602214fdaa1b032be51ff98ecf6b7ee16c
---
 doc/guix.texi               | 19 +++++++++++++++++
 gnu/home/services/media.scm | 42 +++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/doc/guix.texi b/doc/guix.texi
index 858d5751bf..8a3aead56a 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -46383,6 +46383,8 @@ Media Home Services
 @subsection Media Home Services
 
 @cindex kodi
+@subsubheading Kodi Services
+
 The @uref{https://kodi.tv, Kodi media center} can be run as a daemon on
 a media server.  With the @code{(gnu home services kodi)} service, you
 can configure Kodi to run upon login.
@@ -46415,6 +46417,23 @@ Media Home Services
 @end table
 @end deftp
 
+@cindex jellyfin
+@subsubheading Jellyfin Services
+
+The @code{home-jellyfin-mpv-shim-service-type} in the @code{(gnu home services media)} module runs a cast client for the @uref{https://jellyfin.org/, Jellyfin} media system.
+
+To enable, add this to your home services:
+
+@lisp
+(service home-jellyfin-mpv-shim-service-type #f)
+@end lisp
+
+The service only starts if @code{jellyfin-mpv-shim} has been configured with a remote server and credentials.  This must be done manually, by launching @code{jellyfin-mpv-shim}.  After configuring the server, the service will start automatically when you log in.
+
+@defvar home-jellyfin-mpv-shim-service-type
+The type of the Jellyfin MPV Shim service.
+@end defvar
+
 @node Networking Home Services
 @subsection Networking Home Services
 
diff --git a/gnu/home/services/media.scm b/gnu/home/services/media.scm
index c6454dfe15..a7fcf75b06 100644
--- a/gnu/home/services/media.scm
+++ b/gnu/home/services/media.scm
@@ -19,8 +19,10 @@
 (define-module (gnu home services media)
   #:use-module (srfi srfi-26)
   #:use-module (gnu home services)
+  #:use-module (gnu home services desktop)
   #:use-module (gnu home services shepherd)
   #:use-module (gnu packages kodi)
+  #:use-module (gnu packages video)
   #:use-module (gnu services configuration)
   #:use-module (gnu services shepherd)
   #:use-module (guix records)
@@ -66,3 +68,43 @@ (define home-kodi-service-type
    (description
     "Install and configure the Kodi media center so that it runs as a Shepherd
 service.")))
+
+(define (jellyfin-mpv-shim-shepherd-service _ignore)
+  (list (shepherd-service
+         (documentation "Jellyfin MPV Shim.")
+         (provision '(jellyfin-mpv-shim jellyfin-client))
+
+         ;; Depend on 'x11-display', which sets 'DISPLAY' if an X11 server is
+         ;; available, and fails to start otherwise.
+         (requirement '(x11-display))
+
+         (modules '((srfi srfi-1)
+                    (srfi srfi-26)
+                    (srfi srfi-98)))
+         (start #~(lambda _
+                    ;; Only start if a server has been configured.
+                    (if (file-exists?
+                         (string-append
+                          (get-environment-variable "XDG_CONFIG_HOME")
+                          "/jellyfin-mpv-shim/cred.json"))
+                        (fork+exec-command
+                         (list #$(file-append jellyfin-mpv-shim "/bin/jellyfin-mpv-shim"))
+
+                         ;; Inherit the 'DISPLAY' variable set by 'x11-display'.
+                         #:environment-variables
+                         (cons (string-append "DISPLAY=" (getenv "DISPLAY"))
+                               (remove (cut string-prefix? "DISPLAY=" <>)
+                                       (default-environment-variables))))
+                        #f)))
+         (stop #~(make-kill-destructor)))))
+
+(define-public home-jellyfin-mpv-shim-service-type
+  (service-type
+   (name 'home-jellyfin-mpv-shim)
+   (extensions (list (service-extension home-shepherd-service-type
+                                        jellyfin-mpv-shim-shepherd-service)
+                     ;; Ensure 'home-x11-service-type' is instantiated so we
+                     ;; can depend on the Shepherd 'x11-display' service.
+                     (service-extension home-x11-service-type
+                                        (const #t))))
+   (description "Run Jellyfin MPV Shim.")))

base-commit: 7758e63f7a89f53fbb7c7a265ae472af0a8dfab0
-- 
2.41.0

[bug#69692] [PATCH] gnu: Add home-jellyfin-mpv-shim-service-type.

[Skyler Ferris via Guix-patches via]

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Hi Ian,

I don't have the setup required to try running this service but 2 things stand out to me when reading through it.

On 3/9/24 21:24, Ian Eure wrote:

> +To enable, add this to your home services:
> +
> +@lisp
> +(service home-jellyfin-mpv-shim-service-type #f)
> +@end lisp

You can add a default-value field to the service definition like so:

(define-public home-jellyfin-mpv-shim-service-type
  (service-type
   (name 'home-jellyfin-mpv-shim)
   (default-value #f)
   (extensions (list (service-extension home-shepherd-service-type
                                        jellyfin-mpv-shim-shepherd-service)
                     ;; Ensure 'home-x11-service-type' is instantiated so we
                     ;; can depend on the Shepherd 'x11-display' service.
                     (service-extension home-x11-service-type
                                        (const #t))))
   (description "Run Jellyfin MPV Shim.")))

Then, users can simply use (service home-jellyfish-mpv-shim-service-type) without having to specify #f manually And if the service ever changes in the future and this value becomes useful then you can provide a reasonable default without requiring users to change their code. (https://guix.gnu.org/manual/en/html_node/Service-Reference.html)

> +
> +The service only starts if @code{jellyfin-mpv-shim} has been configured with a remote server and credentials.  This must be done manually, by launching @code{jellyfin-mpv-shim}.  After configuring the server, the service will start automatically when you log in.

Would it make sense to launch this program automatically if it is not configured? Presumably if someone adds the service then they want to configure a server. The value passed to the service could be used to specify whether or not the program should automatically launch so that users who do not want this behavior can disable it (note that if you decide to implement this then the configuration value should be an instance of a new structure defined to store configuration for this service, not a simple boolean; again, this makes things easier in the future so that if you want to add more fields pre-existing code will still work).

Regards,
Skyler

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[bug#69692] [PATCH] gnu: Add home-jellyfin-mpv-shim-service-type.

[Ian Eure]

Hi Skyler,

Sorry for the extremely delayed response here.

Skyler Ferris <skyvine@protonmail.com> writes:

> Hi Ian,
>
> I don't have the setup required to try running this service but 
> 2 things stand out to me when reading through it.
>
> On 3/9/24 21:24, Ian Eure wrote:
>
>  +To enable, add this to your home services:
> +
> +@lisp
> +(service home-jellyfin-mpv-shim-service-type #f)
> +@end lisp
>
> You can add a default-value field to the service definition like 
> so:
>
> (define-public home-jellyfin-mpv-shim-service-type
>   (service-type
>    (name 'home-jellyfin-mpv-shim)
>    (default-value #f)
>    (extensions (list (service-extension 
>    home-shepherd-service-type
>                                         jellyfin-mpv-shim-shepherd-service)
>                      ;; Ensure 'home-x11-service-type' is 
>                      instantiated so we
>                      ;; can depend on the Shepherd 'x11-display' 
>                      service.
>                      (service-extension home-x11-service-type
>                                         (const #t))))
>    (description "Run Jellyfin MPV Shim.")))
> Then, users can simply use (service 
> home-jellyfish-mpv-shim-service-type) without having to specify 
> #f manually And if the
> service ever changes in the future and this value becomes useful 
> then you can provide a reasonable default without requiring
> users to change their 
> code. (https://guix.gnu.org/manual/en/html_node/Service-Reference.html)
>

Thank you for the suggestion, I’ll incorporate it and send a 
revised patch after we’re in agreement on the launch behavior.

>  +
> +The service only starts if @code{jellyfin-mpv-shim} has been 
> configured with a remote server and credentials.  This must be 
> done manually, by launching @code{jellyfin-mpv-shim}.  After 
> configuring the server, the service will start automatically 
> when you log in.
>
> Would it make sense to launch this program automatically if it 
> is not configured?
>

I don’t think it would.  When it launches in an unconfigured 
state, you get a very generic "Server Configuration" window, with 
no icon or indication what server you’re configuring, or what for. 
It makes perfect sense if you run the program and that window 
appears, and not much sense at all if it just happens when you log 
in.


> Presumably if someone adds the service then they want to 
> configure a server.

Agreed.  However, configuring the server is a manual action, and 
it doesn’t feel burdensome to manually run the program to do it. 
There isn’t a good way to configure the remote server 
declaratively, since this process involves exchanging a username 
and password for an authentication token, which must be done over 
the network.  You probably wouldn’t want to commit your auth token 
to a repo containing your home configuration, and Guix has no 
facility for securely handling things like this.  So it has to be 
done by hand.


> The value passed to the service could be used to specify whether 
> or not the program should automatically launch so that users who 
> do not want this behavior can disable it (note that if you 
> decide to implement this then the configuration value should be 
> an instance of a new structure defined to store configuration 
> for this service, not a simple boolean; again, this makes things 
> easier in the future so that if you want to add more fields 
> pre-existing code will still work).
>

Making auto-launch configurable doesn’t seem like a good idea to 
me.  It would only ever apply to the very first launch, and 
wouldn’t significantly change the bounds of the problem.  If the 
default is to launch unconfigured, you get the confusing behavior 
I want to avoid.  If the default is to not launch unconfigured, I 
don’t think anyone would ever change that setting -- it’s be much 
easier to launch the program than to change the setting and `guix 
home reconfigure'.

Thanks,

  — Ian