From 0d8c62f7b347966ca545dd77528a31780b94f792 Mon Sep 17 00:00:00 2001
From: Gregor Kleen <gkleen@yggdrasil.li>
Date: Sun, 24 Nov 2019 18:50:14 +0100
Subject: refactor borgbackup

---
 custom/borgbackup.nix      | 16 +++++++---------
 custom/btrfs-snapshots.nix | 11 +++--------
 custom/lvm-snapshots.nix   |  7 ++++++-
 3 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/custom/borgbackup.nix b/custom/borgbackup.nix
index 3871af0a..0db4b5da 100644
--- a/custom/borgbackup.nix
+++ b/custom/borgbackup.nix
@@ -21,7 +21,7 @@ let
 
   systemdPath = path: escapeSystemdPath (if cfg.snapshots == "lvm" then "${path.VG}-${path.LV}" else path);
 
-  withPrefix = path: config.services.btrfs-snapshots.mountPrefix + path;
+  withSuffix = path: path + if cfg.snapshots == "btrfs" then config.services.btrfs-snapshots.mountSuffix else config.services.lvm-snapshots.mountSuffix;
 
   mountPoint = if cfg.snapshots == "lvm" then config.services.lvm-snapshots.mountPoint else config.services.btrfs-snapshots.mountPoint;
 
@@ -86,18 +86,16 @@ in {
     };
   };
 
-  imports = [
-    ./lvm-snapshots.nix
-    ./btrfs-snapshots.nix
-  ];
+  imports =
+       optional (cfg.snapshots == "lvm")   ./lvm-snapshots.nix
+    ++ optional (cfg.snapshats == "btrfs") ./btrfs-snapshots.nix;
 
   config = mkIf (any (t: t.paths != []) (attrValues cfg.targets)) {
-  
     services.btrfs-snapshots.enable = mkIf (cfg.snapshots == "btrfs") true;
 
     services.lvm-snapshots.snapshots = mkIf (cfg.snapshots == "lvm") (listToAttrs (map (path: nameValuePair (path.VG + "-" + path.LV) {
       inherit (path) LV VG; 
-      mountName = withPrefix (path.VG + "-" + path.LV);
+      mountName = withSuffix (path.VG + "-" + path.LV);
     }) (unique (flatten (mapAttrsToList (target: tCfg: tCfg.paths) cfg.targets)))));
 
     systemd.targets."timers-borg" = {
@@ -159,12 +157,12 @@ in {
       unitConfig = {
         AssertPathIsDirectory = mkIf (tCfg.lock != null) "/var/lock";
         DefaultDependencies = false;
-        RequiresMountsFor = mkIf (cfg.snapshots == "lvm") [ "${mountPoint}/${withPrefix "%I"}" ];
+        RequiresMountsFor = mkIf (cfg.snapshots == "lvm") [ "${mountPoint}/${withSuffix "%I"}" ];
       };
 
       serviceConfig = {
         Type = "oneshot";
-        WorkingDirectory = if (cfg.snapshots == null) then "%I" else (if (cfg.snapshots == "lvm") then "${mountPoint}/${withPrefix "%I"}" else "${mountPoint}/${withPrefix "%i"}");
+        WorkingDirectory = if (cfg.snapshots == null) then "%I" else (if (cfg.snapshots == "lvm") then "${withSuffix "%I"}" else "${mountPoint}/${withPrefix "%i"}");
         Nice = 15;
         IOSchedulingClass = 2;
         IOSchedulingPriority = 7;
diff --git a/custom/btrfs-snapshots.nix b/custom/btrfs-snapshots.nix
index 39e0bf0c..034b5019 100644
--- a/custom/btrfs-snapshots.nix
+++ b/custom/btrfs-snapshots.nix
@@ -5,21 +5,16 @@ with lib;
 let
   cfg = config.services.btrfs-snapshots;
 
-  snapshotMount = str: "${cfg.mountPoint}/${cfg.mountPrefix}${str}";
+  snapshotMount = str: "${str}${cfg.mountSuffix}";
 in {
   options = {
 
     services.btrfs-snapshots = {
       enable = mkEnableOption "a systemd unit for btrfs snapshots";   
 
-      mountPoint = mkOption {
-        type = types.path;
-        default = "/mnt";
-      };
-
-      mountPrefix = mkOption {
+      mountSuffix = mkOption {
         type = types.str;
-        default = "snapshot-";
+        default = ".snapshot";
       };
 
       readOnly = mkOption {
diff --git a/custom/lvm-snapshots.nix b/custom/lvm-snapshots.nix
index 98c64330..13cbf421 100644
--- a/custom/lvm-snapshots.nix
+++ b/custom/lvm-snapshots.nix
@@ -7,7 +7,7 @@ let
   cfg = config.services.lvm-snapshots;
 
   snapshotMount = name: "${cfg.mountPoint}/${if isNull cfg.snapshots."${name}".mountName then name else cfg.snapshots."${name}".mountName}";
-  snapshotName = name: "${name}-snapshot";
+  snapshotName = name: "${name}-${cfg.mountSuffix}";
 
   snapshotConfig = {
     options = {
@@ -53,6 +53,11 @@ in {
         type = types.path;
         default = "/mnt";
       };
+
+      mountSuffix = mkOption {
+        type = types.str;
+        default = "-snapshot";
+      };
     };
   };
 
-- 
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