nixos/programs/tmux: specify wanted plugins

Currently it's rather difficult to install tmux plugins. The process involves two steps:
  1. Specify the correct `pkg.tmuxPlugins` package in `environment.systemPackages`
  2. Adding to the configuration file to instantiate the plugin.

This commit allows the user to specify a list of plugins under `programs.tmux.plugins`.

Update nixos/modules/programs/tmux.nix

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

3 files changed, 25 insertions, 1 deletions

diff --git a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
index 436157515eb..9f5279732fe 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
@@ -712,6 +712,15 @@
           warning.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <literal>programs.tmux</literal> has a new option
+          <literal>plugins</literal> that accepts a list of packages
+          from the <literal>tmuxPlugins</literal> group. The specified
+          packages are added to the system and loaded by
+          <literal>tmux</literal>.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
 </section>
diff --git a/nixos/doc/manual/release-notes/rl-2205.section.md b/nixos/doc/manual/release-notes/rl-2205.section.md
index 9d919711cb7..629672259b2 100644
--- a/nixos/doc/manual/release-notes/rl-2205.section.md
+++ b/nixos/doc/manual/release-notes/rl-2205.section.md
@@ -243,4 +243,6 @@ In addition to numerous new and upgraded packages, this release has the followin
   Reason is that the old name has been deprecated upstream.
   Using the old option name will still work, but produce a warning.
 
+- `programs.tmux` has a new option `plugins` that accepts a list of packages from the `tmuxPlugins` group. The specified packages are added to the system and loaded by `tmux`.
+
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
diff --git a/nixos/modules/programs/tmux.nix b/nixos/modules/programs/tmux.nix
index c39908751d2..74b3fbd9ac0 100644
--- a/nixos/modules/programs/tmux.nix
+++ b/nixos/modules/programs/tmux.nix
@@ -52,6 +52,12 @@ let
     set  -s escape-time       ${toString cfg.escapeTime}
     set  -g history-limit     ${toString cfg.historyLimit}
 
+    ${lib.optionalString (cfg.plugins != []) ''
+    # Run plugins
+    ${lib.concatMapStringsSep "\n" (x: "run-shell ${x.rtp}") cfg.plugins}
+
+    ''}
+
     ${cfg.extraConfig}
   '';
 
@@ -165,6 +171,13 @@ in {
           downside it doesn't survive user logout.
         '';
       };
+
+      plugins = mkOption {
+        default = [];
+        type = types.listOf types.package;
+        description = "List of plugins to install.";
+        example = lib.literalExpression "[ pkgs.tmuxPlugins.nord ]";
+      };
     };
   };
 
@@ -174,7 +187,7 @@ in {
     environment = {
       etc."tmux.conf".text = tmuxConf;
 
-      systemPackages = [ pkgs.tmux ];
+      systemPackages = [ pkgs.tmux ] ++ cfg.plugins;
 
       variables = {
         TMUX_TMPDIR = lib.optional cfg.secureSocket ''''${XDG_RUNTIME_DIR:-"/run/user/$(id -u)"}'';