fetchWallpaper: add from lassulus

3modules/default.nix

@@ -2,7 +2,6 @@ _:
 
 {
   imports = [
-    ./awesome-extra.nix
     ./bump-distrowatch.nix
     ./deluge.nix
     ./etherpad.nix

3modules/fetchWallpaper.nix

@@ -0,0 +1,80 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.krebs.fetchWallpaper;
+
+  fetchWallpaperScript = pkgs.writers.writeDash "fetchWallpaper" ''
+    set -euf
+
+    mkdir -p ${cfg.stateDir}
+    chmod o+rx ${cfg.stateDir}
+    cd ${cfg.stateDir}
+    (curl -s -o wallpaper.tmp -z wallpaper.tmp ${lib.escapeShellArg cfg.url} && cp wallpaper.tmp wallpaper) || :
+    feh --no-fehbg --bg-scale wallpaper
+  '';
+
+in {
+  options.lass.fetchWallpaper = {
+    enable = lib.mkEnableOption "fetch wallpaper";
+    url = lib.mkOption {
+      type = lib.types.str;
+    };
+    timerConfig = lib.mkOption {
+      type = lib.types.unspecified;
+      default = {
+        OnCalendar = "*:00,10,20,30,40,50";
+      };
+    };
+    stateDir = lib.mkOption {
+      type = lib.types.str;
+      default = "/var/lib/wallpaper";
+    };
+    display = lib.mkOption {
+      type = lib.types.str;
+      default = ":${toString config.services.xserver.display}";
+    };
+    unitConfig = lib.mkOption {
+      type = lib.types.attrsOf lib.types.str;
+      description = "Extra unit configuration for fetchWallpaper to define conditions and assertions for the unit";
+      example = lib.literalExample ''
+        # do not start when running on umts
+        { ConditionPathExists = "!/var/run/ppp0.pid"; }
+      '';
+      default = {};
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.timers.fetchWallpaper = {
+      description = "fetch wallpaper timer";
+      wantedBy = [ "timers.target" ];
+
+      timerConfig = cfg.timerConfig;
+    };
+    systemd.services.fetchWallpaper = {
+      description = "fetch wallpaper";
+      after = [ "network.target" ];
+
+      path = with pkgs; [
+        curl
+        feh
+      ];
+
+      environment = {
+        URL = cfg.url;
+        DISPLAY = cfg.display;
+      };
+      restartIfChanged = true;
+
+      serviceConfig = {
+        Type = "simple";
+        ExecStart = fetchWallpaperScript;
+        User = "fetchWallpaper";
+        StateDirectory = true;
+        StateDirectoryMode = "0755";
+      };
+
+      unitConfig = cfg.unitConfig;
+    };
+  };
+}