nixos_forgejo/backup.nix

{config, pkgs, lib, ... }:

# NOTE: For this to work you should use MariaDB as your Forgejo-Database running on the same host. If this is not the case, update this script accordingly.
let
  makeBackupForRepo = repo: lib.getExe (pkgs.writeShellScriptBin "forgejo-borgbackup" ''
    #!/bin/sh
    set -e
    #stop forgejo
    systemctl stop forgejo.service
    # Dump Forgejo DB
    MYSQL_DATABASE="forgejodb"
    ${pkgs.mariadb}/bin/mysqldump -u root ''${MYSQL_DATABASE} > /borgbackupcache/forgejobackup.sql
    # BorgBackup
    export BORG_PASSCOMMAND="cat /etc/nixos/borgpassword"
    export BORG_REPO=${repo}
    export BACKUP_NAME="forgejo-$(date +%Y-%m-%d-%H-%M)"

    # Add everything to be backed up
    ${pkgs.borgbackup}/bin/borg create --verbose --filter AME --list --stats --show-rc --compression lz4 --exclude-caches \
      $BORG_REPO::$BACKUP_NAME \
      /var/lib/forgejo/repositories/ \
      /var/lib/forgejo/data/ \
      /borgbackupcache/forgejobackup.sql \
      /etc/nixos/
    # Delete DB dump
    rm /borgbackupcache/forgejobackup.sql
    # Start Forgejo again
    systemctl start forgejo.service
    # Prune old backups
    ${pkgs.borgbackup}/bin/borg prune --list $BORG_REPO --prefix 'forgejo-' --show-rc --keep-daily=7 --keep-weekly=4 --keep-monthly=6
  '');
  repos = repolistfile: lib.pipe repolistfile [
    builtins.readFile
    (lib.splitString "\n")
    (lib.filter (s: s != ""))
  ];
  backups = repolistfile: builtins.map makeBackupForRepo (repos repolistfile);
  in
  {
    environment.systemPackages = [ pkgs.borgbackup ];
    # Create folders
    systemd.tmpfiles.rules = [
	    "d /borgbackupcache 700 root root"
    ];
    # Backup timer
   systemd.services.borg-backup = {
   description = "Borg Backup for Forgejo and the Forgejo MySQL Database";
   serviceConfig = {
     ExecStart = lib.getExe (pkgs.writeShellScriptBin "doBackups" (lib.concatStringsSep ";" (backups config._module.args.borgrepolistfile)));
     User = "root";
   };
   requires= ["mysql.service"];
   after = ["forgejo.service" "mysql.service" "network-online.target"];
   wants = ["network-online.target"];
   wantedBy = [ "multi-user.target" ];
 };

 systemd.timers.borg-backup = {
   description = "Daily Borg Backup Timer";
   wantedBy = [ "timers.target" ];
   timerConfig = {
     OnActiveSec = "30s";
     OnCalendar = "daily";
     Persistent = true;
   };
 };
  }