1 files changed, 99 insertions, 0 deletions
diff --git a/home/environ/vtmp.nix b/home/environ/vtmp.nix
new file mode 100644
index 0000000..e15778d
--- /dev/null
+++ b/home/environ/vtmp.nix
@@ -0,0 +1,99 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.local.environ;
+
+  vtmp-sync = pkgs.writeShellScript "vtmp-sync" ''
+    if [ $# -ne 3 ]; then
+      echo "usage: $0 <remote hostname> <local hostname> <boot id>" >&2
+      exit 1
+    fi
+
+    local="$2"
+    remote="$1"
+    boot_id="$(echo "$3" | ${pkgs.coreutils}/bin/head -c8)"
+
+    rsync="${lib.getExe pkgs.rsync}"
+
+    cd "$HOME/vtmp"
+    mkdir -p "$remote"
+
+    declare -a rsync_opts
+    rsync_opts+=("-glprtxz")
+    rsync_opts+=("--open-noatime")
+    rsync_opts+=("--preallocate")
+    rsync_opts+=("--max-size=1G")
+    rsync_opts+=("--rsh=${lib.getExe pkgs.openssh} -o BatchMode=yes")
+    rsync_opts+=("--log-file=$remote/.rsync.log")
+    rsync_opts+=("--filter=- /$local.$boot_id/")
+    rsync_opts+=("--filter=- /$remote/")
+
+    # Push to $remote from $local
+    "$rsync" "''${rsync_opts[@]}" -- ./ "$remote:vtmp/$local.$boot_id/"
+
+    # Pull from $remote to $local
+    "$rsync" "''${rsync_opts[@]}" -- "$remote:vtmp/" "./$remote/"
+  '';
+in {
+  options.local.environ = {
+    vtmpSyncHost = mkOption {
+      type = with lib.types; nullOr str;
+      default = null;
+    };
+  };
+
+  config = mkMerge [
+    (mkIf cfg.enable {
+      systemd.user.tmpfiles.rules = [
+        "d %t/vtmp 0700"
+      ];
+
+      home.file = {
+        "vtmp".source = config.lib.file.mkOutOfStoreSymlink "/run/user/${toString config.local.uid}/vtmp";
+      };
+
+      gtk.gtk3.bookmarks = [
+        "file://${config.home.homeDirectory}/vtmp"
+        "file://${config.home.homeDirectory}/tmp"
+      ];
+    })
+    (mkIf (cfg.enable && cfg.vtmpSyncHost != null) {
+      programs.ssh = {
+        extraOptionOverrides.PermitLocalCommand = "yes";
+
+        matchBlocks.${cfg.vtmpSyncHost}.extraOptions.LocalCommand =
+          "systemctl --user import-environment SSH_AUTH_SOCK; "
+          + "systemctl --user start vtmp-sync.timer";
+      };
+
+      systemd.user = {
+        targets.vtmp-sync-failure = {
+          Unit = {
+            Conflicts = ["vtmp-sync.timer"];
+          };
+        };
+
+        services.vtmp-sync = {
+          Unit = {
+            OnFailure = ["vtmp-sync-failure.target"];
+          };
+
+          Service = {
+            ExecStart = "${vtmp-sync} ${cfg.vtmpSyncHost} %l %b";
+          };
+        };
+
+        timers.vtmp-sync = {
+          Timer = {
+            OnActiveSec = "15s";
+            OnUnitInactiveSec = "1h";
+          };
+        };
+      };
+    })
+  ];
+}