Adds LNbits Borg backup module

Implements a new module for backing up LNbits data using Borg.

This module automates hourly backups, encrypts the data, and provides point-in-time recovery. It includes scripts for listing, restoring, and mounting backups. A comprehensive setup guide is provided in the documentation.

The configuration allows specifying the Borg repository location, schedule, compression settings, retention policy, and SSH key for secure access.

config/machines/example-machine/borg-lnbits.nix

@@ -0,0 +1,35 @@
+{ config, pkgs, ... }:
+
+{
+  imports = [
+    ./modules/lnbits-backup.nix  # Add this line
+  ];
+
+  # Enable LNbits Borg backup
+  services.lnbits-backup = {
+    enable = true;
+
+    # Repository path - update with your actual path
+    # Option 1: Traditional format
+    # repository = "borg@192.168.1.100:/mnt/my_ssd/borg-backups/lnbits";
+
+    # Option 2: Full SSH URL format (note double slash for absolute path)
+    repository = "ssh://borg@<your-backup-ip>//mnt/borg-backups/lnbits";
+
+    # Backup schedule
+    schedule = "*:0/15";  # Backup schedule (hourly, daily, or systemd timer format)
+
+    # Compression with auto-detection
+    # "auto" skips compression for already-compressed files (images, videos, etc.)
+    compression = "auto,lz4";      # For Raspberry Pi (faster)
+    # compression = "auto,zstd";   # For RockPro64 (better compression)
+
+    # Retention policy, leave all of these
+    retention = {
+      hourly = 24;   # Last 24 hours
+      daily = 7;     # Last 7 days
+      weekly = 4;    # Last 4 weeks
+      monthly = 6;   # Last 6 months
+    };
+  };
+}

config/machines/example-machine/configuration.nix

@@ -16,6 +16,10 @@ in
     # Import boot configuration (bootloader settings)
     ./boot.nix
 
+    # BORG backup
+    # read docs/lnbits-borg-backup-guide.md
+    # ./borg-lnbits.nix
+
     # Import any machine-specific services
     # Comment out or remove if not needed
     # ./example-service.nix

config/machines/example-machine/modules/lnbits-backup.nix

@@ -0,0 +1,177 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.lnbits-backup;
+
+in {
+  options.services.lnbits-backup = {
+    enable = mkEnableOption "LNbits Borg Backup Service";
+
+    dataPath = mkOption {
+      type = types.path;
+      default = "/var/lib/lnbits/data";
+      description = "Path to LNbits data directory";
+    };
+
+    repository = mkOption {
+      type = types.str;
+      example = "ssh://borg@192.168.1.100//mnt/my_ssd/borg-backups/lnbits";
+      description = "Borg repository location (SSH URL or user@host:/path format)";
+    };
+
+    schedule = mkOption {
+      type = types.str;
+      default = "hourly";
+      description = "Backup schedule (hourly, daily, or systemd timer format)";
+    };
+
+    compression = mkOption {
+      type = types.str;
+      default = "auto,lz4";
+      description = "Compression: auto,lz4 (Pi), auto,zstd (RockPro64). 'auto' skips already-compressed files.";
+    };
+
+    passphraseFile = mkOption {
+      type = types.path;
+      default = "/root/secrets/borg-passphrase";
+      description = "Path to Borg passphrase file";
+    };
+
+    sshKeyFile = mkOption {
+      type = types.path;
+      default = "/root/.ssh/borg_backup_key";
+      description = "SSH private key for repository access";
+    };
+
+    retention = {
+      hourly = mkOption { type = types.int; default = 24; };
+      daily = mkOption { type = types.int; default = 7; };
+      weekly = mkOption { type = types.int; default = 4; };
+      monthly = mkOption { type = types.int; default = 6; };
+    };
+
+    alertEmail = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = "Email for alerts (optional)";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services.borgbackup.jobs.lnbits = {
+      paths = [
+        cfg.dataPath
+        "/tmp/lnbits-snapshot.sqlite3"
+      ];
+
+      exclude = [ "*.log" "*.pyc" "__pycache__" "*.tmp" ];
+      repo = cfg.repository;
+
+      encryption = {
+        mode = "repokey-blake2";
+        passCommand = "cat ${cfg.passphraseFile}";
+      };
+
+      compression = cfg.compression;
+      startAt = cfg.schedule;
+      persistentTimer = true;  # Run missed backups after reboots
+
+      prune.keep = {
+        inherit (cfg.retention) hourly daily weekly monthly;
+      };
+
+      preHook = ''
+        echo "=== LNbits Backup Starting: $(date) ==="
+
+        if [ -f "${cfg.dataPath}/database.sqlite3" ]; then
+          echo "Creating SQLite snapshot..."
+          ${pkgs.sqlite}/bin/sqlite3 "${cfg.dataPath}/database.sqlite3" \
+            ".backup '/tmp/lnbits-snapshot.sqlite3'"
+
+          SIZE=$(stat -c%s "/tmp/lnbits-snapshot.sqlite3")
+          echo "Snapshot created: $SIZE bytes"
+
+          if [ "$SIZE" -lt 1000 ]; then
+            echo "ERROR: Snapshot too small!"
+            rm -f /tmp/lnbits-snapshot.sqlite3
+            exit 1
+          fi
+        else
+          echo "ERROR: Database not found!"
+          exit 1
+        fi
+      '';
+
+      postHook = ''
+        rm -f /tmp/lnbits-snapshot.sqlite3
+
+        # Weekly integrity check (Sundays)
+        if [ $(date +%u) -eq 7 ]; then
+          echo "Running weekly integrity check..."
+          ${pkgs.borgbackup}/bin/borg check --repository-only ${cfg.repository}
+        fi
+
+        echo "=== Backup Complete: $(date) ==="
+      '';
+
+      environment = {
+        BORG_RSH = "ssh -i ${cfg.sshKeyFile} -o StrictHostKeyChecking=accept-new";
+      };
+    };
+
+    # Install required packages and helper commands
+    environment.systemPackages = with pkgs; [
+      borgbackup
+      sqlite
+
+      (writeShellScriptBin "lnbits-borg-list" ''
+        export BORG_PASSPHRASE=$(cat ${cfg.passphraseFile})
+        export BORG_RSH="ssh -i ${cfg.sshKeyFile}"
+        ${borgbackup}/bin/borg list ${cfg.repository} "$@"
+      '')
+
+      (writeShellScriptBin "lnbits-borg-info" ''
+        export BORG_PASSPHRASE=$(cat ${cfg.passphraseFile})
+        export BORG_RSH="ssh -i ${cfg.sshKeyFile}"
+        ${borgbackup}/bin/borg info ${cfg.repository} "$@"
+      '')
+
+      (writeShellScriptBin "lnbits-borg-restore" ''
+        if [ $# -lt 1 ]; then
+          echo "Usage: lnbits-borg-restore <archive-name> [destination]"
+          echo ""
+          echo "Available archives:"
+          lnbits-borg-list
+          exit 1
+        fi
+
+        ARCHIVE="$1"
+        DEST="''${2:-/tmp/lnbits-restore}"
+
+        export BORG_PASSPHRASE=$(cat ${cfg.passphraseFile})
+        export BORG_RSH="ssh -i ${cfg.sshKeyFile}"
+
+        mkdir -p "$DEST"
+        cd "$DEST"
+        echo "Restoring to: $DEST"
+        ${borgbackup}/bin/borg extract ${cfg.repository}::$ARCHIVE
+        echo "Done! Restored files in: $DEST"
+      '')
+
+      (writeShellScriptBin "lnbits-borg-mount" ''
+        MOUNT="''${1:-/mnt/borg-browse}"
+
+        export BORG_PASSPHRASE=$(cat ${cfg.passphraseFile})
+        export BORG_RSH="ssh -i ${cfg.sshKeyFile}"
+
+        mkdir -p "$MOUNT"
+        ${borgbackup}/bin/borg mount ${cfg.repository} "$MOUNT"
+        echo "Mounted at: $MOUNT"
+        echo "Unmount: borg umount $MOUNT"
+      '')
+    ];
+  };
+}
+