rclone-snapshots.sh

#!/bin/bash

# -----------------------------
# Configuration
# -----------------------------
set -ex

SOURCES=(
  "/home/"
  "/volume1/folder/"
)

REMOTE="secure:"
CURRENT="$REMOTE/current"
OLD="$REMOTE/old"

KEEP_SNAPSHOTS=300  # Keep last 300 snapshots
MAX_DELETES=10     # Warn if more than this many files deleted

# -----------------------------
# Backup
# -----------------------------
TODAY=$(date +%Y-%m-%d)
DAILY_BACKUP="$OLD/$TODAY"
TOTAL_DELETES=0
EXIT_CODE=0

echo "[INFO] Starting backup for multiple sources into $CURRENT"

for SRC in "${SOURCES[@]}"; do
    RELPATH=$(realpath --relative-to=/ "$SRC")
    TARGET_DIR="$CURRENT/$RELPATH"
    BACKUP_DIR="$DAILY_BACKUP/$RELPATH"

    echo "[INFO] Syncing $SRC → $TARGET_DIR (backup-dir: $BACKUP_DIR)"

    # Run sync and capture output
    SYNC_OUTPUT=$(rclone sync "$SRC" "$TARGET_DIR" --backup-dir "$BACKUP_DIR" --exclude "**/@eaDir/**" --skip-links --delete-excluded 2>&1)
    SYNC_EXIT=$?
    echo "$SYNC_OUTPUT"

    # Count deleted files from backup-dir (files moved there are "deleted" from current)
    if rclone lsf "$BACKUP_DIR" >/dev/null 2>&1; then
        DELETES=$(rclone size "$BACKUP_DIR" --json 2>/dev/null | grep -o '"count":[0-9]*' | cut -d: -f2)
        if [[ -n "$DELETES" && "$DELETES" -gt 0 ]]; then
            echo "[INFO] $DELETES files deleted/changed in $RELPATH"
            TOTAL_DELETES=$((TOTAL_DELETES + DELETES))
        fi
    fi

    if [[ $SYNC_EXIT -ne 0 ]]; then
        EXIT_CODE=1
    fi
done

# Check for excessive deletes
if [[ $TOTAL_DELETES -gt $MAX_DELETES ]]; then
    echo "[WARNING] Excessive deletes detected: $TOTAL_DELETES files (threshold: $MAX_DELETES)"
    EXIT_CODE=1
fi

# -----------------------------
# Rotation
# -----------------------------
echo "[INFO] Performing snapshot rotation"

snapshots=$(rclone lsf "$OLD" --dirs-only | sed 's:/$::' | sort)

if [[ -z "$snapshots" ]]; then
    echo "[INFO] No snapshots to rotate"
    exit $EXIT_CODE
fi

snapshot_count=$(echo "$snapshots" | wc -l)
echo "[INFO] Found $snapshot_count snapshots"

# Keep last KEEP_SNAPSHOTS
keep_snapshots=($(echo "$snapshots" | tail -n "$KEEP_SNAPSHOTS"))
echo "[INFO] Keeping ${#keep_snapshots[@]} snapshots"

# Delete old snapshots
DELETED_COUNT=0
for snap in ${snapshots}; do
    if [[ ! " ${keep_snapshots[@]} " =~ " ${snap} " ]]; then
        echo "[INFO] Deleting old snapshot: $snap"
        if rclone purge "$OLD/$snap"; then
            DELETED_COUNT=$((DELETED_COUNT + 1))
        else
            echo "[ERROR] Failed to delete $snap"
            EXIT_CODE=1
        fi
    fi
done

echo "[INFO] Deleted $DELETED_COUNT old snapshots"
echo "[INFO] Backup and rotation completed"

exit $EXIT_CODE