services/tmptsync: init

hosts/caramel/default.nix

@@ -30,5 +30,6 @@
       nginx
       postgres
       synapse
+      tmptsync
     ]);
 }

modules/default.nix

@@ -18,6 +18,7 @@ in {
     ./services/nginx.nix
     ./services/postgres.nix
     ./services/synapse.nix
+    ./services/tmptsync.nix
   ];
   system = mkAttrsFromPaths [
     ./system/audio.nix

modules/services/tmptsync.nix

@@ -0,0 +1,30 @@
+{ ... }:
+let
+  dir = "/persist/tmptsync";
+in
+{
+  systemd = {
+    services = {
+      tmptsync-load = {
+        before = [ "basic.target" ];
+        after = [ "local-fs.target" "sysinit.target" ];
+        unitConfig.DefaultDependencies = false;
+
+        script = "${../../scripts/tmptsync.sh} load";
+        wantedBy = [ "basic.target" ];
+      };
+
+      tmptsync-save = {
+        script = "${../../scripts/tmptsync.sh} load";
+        wantedBy = [ "basic.target" ];
+      };
+    };
+    timers.tmptsync-save = {
+      timerConfig = {
+        Unit = "tmptsync-save.service";
+        OnBootSec = "30mn";
+        OnUnitActiveSec = "2h";
+      };
+    };
+  };
+}

scripts/tmptsync.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env sh
+#
+# Super simple script that saves clock to file and reads from it later
+# Something like fake-hwclock from debian
+# CC0-1.0
+
+CMD="${1:-save}"
+
+if [ ! -v FILE ]; then
+    echo 'missing $FILE'
+    exit 64
+fi
+
+case $CMD in 
+    save)
+        date -u '+%Y-%m-%d %H:%M:%S' > $FILE
+        ;;
+    load)
+        if [ ! -e $FILE ]; then
+            echo "attempted to load from nonexistent file"
+            exit 65
+        fi
+        NEW=$(cat $FILE)
+        date -u -s "$NEW"
+        ;;
+    *)
+        echo "unknown subcommand"
+        exit 66
+        ;;
+esac