Move all of NixOS to nixos/ in preparation of the repository merge

nixos/modules/services/backup/mysql-backup.nix

@@ -0,0 +1,81 @@
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+let
+
+  inherit (pkgs) mysql gzip;
+
+  cfg = config.services.mysqlBackup ;
+  location = cfg.location ;
+  mysqlBackupCron = db : ''
+    ${cfg.period} ${cfg.user} ${mysql}/bin/mysqldump ${if cfg.singleTransaction then "--single-transaction" else ""} ${db} | ${gzip}/bin/gzip -c > ${location}/${db}.gz
+  '';
+
+in
+
+{
+  options = {
+
+    services.mysqlBackup = {
+
+      enable = mkOption {
+        default = false;
+        description = ''
+          Whether to enable MySQL backups.
+        '';
+      };
+
+      period = mkOption {
+        default = "15 01 * * *";
+        description = ''
+          This option defines (in the format used by cron) when the
+          databases should be dumped.
+          The default is to update at 01:15 (at night) every day.
+        '';
+      };
+
+      user = mkOption {
+        default = "mysql";
+        description = ''
+          User to be used to perform backup.
+        '';
+      };
+
+      databases = mkOption {
+        default = [];
+        description = ''
+          List of database names to dump.
+        '';
+      };
+
+      location = mkOption {
+        default = "/var/backup/mysql";
+        description = ''
+          Location to put the gzipped MySQL database dumps.
+        '';
+      };
+
+      singleTransaction = mkOption {
+        default = false;
+        description = ''
+          Whether to create database dump in a single transaction
+        '';
+      };
+    };
+
+  };
+
+  config = mkIf config.services.mysqlBackup.enable {
+
+    services.cron.systemCronJobs = map mysqlBackupCron config.services.mysqlBackup.databases;
+
+    system.activationScripts.mysqlBackup = stringAfter [ "stdio" "users" ]
+      ''
+        mkdir -m 0700 -p ${config.services.mysqlBackup.location}
+        chown ${config.services.mysqlBackup.user} ${config.services.mysqlBackup.location}
+      '';
+
+  };
+
+}