the_prg_server_configuration/nix-system-configs/modules/system_scripts/gcloud_backup.nix

{
  config,
  pkgs,
  lib,
  ...
}: let
  gcsBucket = "polyteknisk-db-backups-bucket";
  gpgRecipient = "dtu.prg@dtu.dk";

  # Embed the public key directly (not sensitive)
  gpgPublicKey = pkgs.writeText "backup-public-key.asc" ''
    -----BEGIN PGP PUBLIC KEY BLOCK-----

    mQINBGmHsFcBEADuiQeZSU2KMBT3+PAECEi4qW87WbMpeMIJlN7b5dNvSIVgaOie
    n/KNDcZiKL5WkxIoxcEy1k64EQ8oY+xdAgUItZAL4zoB2bBY2rHmbhaRx36rYOdZ
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    8WyIYflHRO0DU8sonnKlDZiwaq/bfu3FL03IsnPVbQOpZ0o8c9HIxDG0efgvO5li
    v+ajiDMld5iwvSBz9+9yDDiSNYPRipNlhaFDaoT9pM6s7ETmRCYQ75T7z0FMaugt
    iTJRz0emyj/canJ2/JrkVBGNw8Kb9JG8Nd6ix2oZagcv96niRKQoqzWyiWizNWnq
    /wQ7QHqMxXGymNseF8Ig/a/0oJs+mRYYCBNj2hkF2COQdHqSr+NduSJfaZGCdHOe
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    0/WNwoCOmLRhGndaW9iqk7Xk7+k43q4CAsEsKhNQnAH7TzHOuOUmM7pSi3mK4Eby
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    DFYqkeE28Uzz52DpHGvbw4cT08w17WWrf6A=
    =jpAS
    -----END PGP PUBLIC KEY BLOCK-----
  '';

  postgresBackupScript = pkgs.writeShellScript "backup-postgresql-wrapper" ''
    export GOOGLE_APPLICATION_CREDENTIALS="${config.sops.secrets.gcloud_bucket.path}"
    export GCS_BUCKET="${gcsBucket}"
    export GPG_RECIPIENT="${gpgRecipient}"
    export GPG_PUBLIC_KEY="${gpgPublicKey}"
    export PATH="${lib.makeBinPath [pkgs.postgresql pkgs.gzip pkgs.google-cloud-sdk pkgs.gnupg]}:$PATH"

    exec ${./backup_postgresql.zsh}
  '';

  mariadbBackupScript = pkgs.writeShellScript "backup-mariadb-wrapper" ''
    export GOOGLE_APPLICATION_CREDENTIALS="${config.sops.secrets.gcloud_bucket.path}"
    export GCS_BUCKET="${gcsBucket}"
    export GPG_RECIPIENT="${gpgRecipient}"
    export GPG_PUBLIC_KEY="${gpgPublicKey}"
    export PATH="${lib.makeBinPath [pkgs.mariadb pkgs.gzip pkgs.google-cloud-sdk pkgs.gnupg]}:$PATH"

    exec ${./backup_mariadb.zsh}
  '';
in {
  systemd.services.backup-postgresql = {
    description = "Backup PostgresSQL databases to GCS";
    serviceConfig = {
      Type = "oneshot";
      User = "postgres";
      ExecStart = "${postgresBackupScript}";
    };
  };

  systemd.timers.backup-postgresql = {
    description = "Timer for PostgresSQL backups";
    wantedBy = ["timers.target"];
    timerConfig = {
      OnCalendar = "Mon,Thu,Sun 03:00";
      Persistent = true;
    };
  };

  systemd.services.backup-mariadb = {
    description = "Backup MariaDB databases to GCS";
    serviceConfig = {
      Type = "oneshot";
      User = "root";
      ExecStart = "${mariadbBackupScript}";
    };
  };

  systemd.timers.backup-mariadb = {
    description = "Timer for MariaDB backups";
    wantedBy = ["timers.target"];
    timerConfig = {
      OnCalendar = "Mon,Thu,Sun 04:00";
      Persistent = true;
    };
  };
}