From 919f2b2b6292436570613e7f7166eb992b12255f Mon Sep 17 00:00:00 2001
From: Tom Hubrecht <tom@hubrecht.ovh>
Date: Sun, 5 Feb 2023 14:48:46 +0100
Subject: [PATCH] nixos/borgmatic: Allow defining multiple configurations

---
 .../manual/release-notes/rl-2305.section.md   |  2 +
 nixos/modules/services/backup/borgmatic.nix   | 86 +++++++++++--------
 2 files changed, 54 insertions(+), 34 deletions(-)

diff --git a/nixos/doc/manual/release-notes/rl-2305.section.md b/nixos/doc/manual/release-notes/rl-2305.section.md
index c81cbc69f94e..5437a4ab6521 100644
--- a/nixos/doc/manual/release-notes/rl-2305.section.md
+++ b/nixos/doc/manual/release-notes/rl-2305.section.md
@@ -148,6 +148,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - NixOS now defaults to using nsncd (a non-caching reimplementation in Rust) as NSS lookup dispatcher, instead of the buggy and deprecated glibc-provided nscd. If you need to switch back, set `services.nscd.enableNsncd = false`, but please open an issue in nixpkgs so your issue can be fixed.
 
+- `services.borgmatic` now allows for multiple configurations, placed in `/etc/borgmatic.d/`, you can define them with `services.borgmatic.configurations`.
+
 - The `dnsmasq` service now takes configuration via the
   `services.dnsmasq.settings` attribute set. The option
   `services.dnsmasq.extraConfig` will be deprecated when NixOS 22.11 reaches
diff --git a/nixos/modules/services/backup/borgmatic.nix b/nixos/modules/services/backup/borgmatic.nix
index 73c4acda3936..e7cd6ae4bb57 100644
--- a/nixos/modules/services/backup/borgmatic.nix
+++ b/nixos/modules/services/backup/borgmatic.nix
@@ -5,44 +5,58 @@ with lib;
 let
   cfg = config.services.borgmatic;
   settingsFormat = pkgs.formats.yaml { };
+
+  cfgType = with types; submodule {
+    freeformType = settingsFormat.type;
+    options.location = {
+      source_directories = mkOption {
+        type = listOf str;
+        description = mdDoc ''
+          List of source directories to backup (required). Globs and
+          tildes are expanded.
+        '';
+        example = [ "/home" "/etc" "/var/log/syslog*" ];
+      };
+      repositories = mkOption {
+        type = listOf str;
+        description = mdDoc ''
+          Paths to local or remote repositories (required). Tildes are
+          expanded. Multiple repositories are backed up to in
+          sequence. Borg placeholders can be used. See the output of
+          "borg help placeholders" for details. See ssh_command for
+          SSH options like identity file or port. If systemd service
+          is used, then add local repository paths in the systemd
+          service file to the ReadWritePaths list.
+        '';
+        example = [
+          "ssh://user@backupserver/./sourcehostname.borg"
+          "ssh://user@backupserver/./{fqdn}"
+          "/var/local/backups/local.borg"
+        ];
+      };
+    };
+  };
+
   cfgfile = settingsFormat.generate "config.yaml" cfg.settings;
-in {
+in
+{
   options.services.borgmatic = {
-    enable = mkEnableOption (lib.mdDoc "borgmatic");
+    enable = mkEnableOption (mdDoc "borgmatic");
 
     settings = mkOption {
-      description = lib.mdDoc ''
+      description = mdDoc ''
         See https://torsion.org/borgmatic/docs/reference/configuration/
       '';
-      type = types.submodule {
-        freeformType = settingsFormat.type;
-        options.location = {
-          source_directories = mkOption {
-            type = types.listOf types.str;
-            description = lib.mdDoc ''
-              List of source directories to backup (required). Globs and
-              tildes are expanded.
-            '';
-            example = [ "/home" "/etc" "/var/log/syslog*" ];
-          };
-          repositories = mkOption {
-            type = types.listOf types.str;
-            description = lib.mdDoc ''
-              Paths to local or remote repositories (required). Tildes are
-              expanded. Multiple repositories are backed up to in
-              sequence. Borg placeholders can be used. See the output of
-              "borg help placeholders" for details. See ssh_command for
-              SSH options like identity file or port. If systemd service
-              is used, then add local repository paths in the systemd
-              service file to the ReadWritePaths list.
-            '';
-            example = [
-              "user@backupserver:sourcehostname.borg"
-              "user@backupserver:{fqdn}"
-            ];
-          };
-        };
-      };
+      default = null;
+      type = types.nullOr cfgType;
+    };
+
+    configurations = mkOption {
+      description = mdDoc ''
+        Set of borgmatic configurations, see https://torsion.org/borgmatic/docs/reference/configuration/
+      '';
+      default = { };
+      type = types.attrsOf cfgType;
     };
   };
 
@@ -50,9 +64,13 @@ in {
 
     environment.systemPackages = [ pkgs.borgmatic ];
 
-    environment.etc."borgmatic/config.yaml".source = cfgfile;
+    environment.etc = (optionalAttrs (cfg.settings != null) { "borgmatic/config.yaml".source = cfgfile; }) //
+      mapAttrs'
+        (name: value: nameValuePair
+          "borgmatic.d/${name}.yaml"
+          { source = settingsFormat.generate "${name}.yaml" value; })
+        cfg.configurations;
 
     systemd.packages = [ pkgs.borgmatic ];
-
   };
 }