add epa

hosts/yodaTux/configuration.nix

@@ -60,6 +60,7 @@
       ../../modules/print-and-scan.nix
       #../../modules/waydroid.nix
       ../../modules/uni-vpn.nix
+      #../../modules/epa.nix
 
       ../../modules/games.nix
       #../../modules/dosbox-x.nix

modules/epa.nix

@@ -0,0 +1,17 @@
+# Elektronische Patientenakte (ePA)
+
+{ config, pkgs, lib, ... }:
+{
+  imports = [
+    ./snap.nix
+  ];
+
+  # Manually add
+  #   https://snapcraft.io/tk-safe
+  # with
+  #   snap install tk-safe
+
+  # TODO: There is an error during installation.
+  #   Jan 09 10:51:51 yodaTux systemd[1]: snap.tk-safe.pcscd.pcscd-socket.socket: Socket service snap.tk-safe.pcscd.service not loaded, refusing.
+  #   Jan 09 10:51:51 yodaTux systemd[1]: Failed to listen on Socket pcscd-socket for snap application tk-safe.pcscd.
+}

modules/snap.nix

@@ -0,0 +1,18 @@
+# https://wiki.nixos.org/wiki/Snap
+# - No official support in nixpkgs
+# - There is a community module
+# https://github.com/nix-community/nix-snapd?tab=readme-ov-file#channels
+# - Community module `nix-snapd` provides option `services.snap.enable`
+
+{ config, pkgs, lib, ... }:
+let
+  sources = import ../nix/sources.nix;
+in
+{
+  imports = [
+    # Import nix-snapd with niv.
+    (import sources.nix-snapd).nixosModules.default
+  ];
+
+  services.snap.enable = true;
+}

nix/sources.json

@@ -23,6 +23,18 @@
         "url": "https://github.com/nix-community/home-manager/archive/613691f285dad87694c2ba1c9e6298d04736292d.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
+    "nix-snapd": {
+        "branch": "main",
+        "description": "Snap package for Nix and NixOS",
+        "homepage": null,
+        "owner": "nix-community",
+        "repo": "nix-snapd",
+        "rev": "355a1ed0141b6fd3093e3cb7b3492e6e67913681",
+        "sha256": "1z2znfvn1d7066vym25h3cnam7n29br2417qv26yzw0lk88kxdpz",
+        "type": "tarball",
+        "url": "https://github.com/nix-community/nix-snapd/archive/355a1ed0141b6fd3093e3cb7b3492e6e67913681.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "nixpkgs": {
         "branch": "nixos-24.11",
         "description": "Nix Packages collection",