mariadb-backup restore

mariadb_restore.sh

#!/bin/bash

BACKUP_BASE="$1"
TARGET_INC_FILE="$2"

if [ ! -d "$BACKUP_BASE" ]; then
    echo "$BACKUP_BASE is not a valid directory"
    echo "Usage: $0 <backup_dir> [stop_after_incremental_file]"
    exit 1
fi

# === CONFIGURATION ===
FULL_BACKUP_DIR="$BACKUP_BASE/full"
INCREMENTAL_BASE_DIR="$BACKUP_BASE/inc"
WORKDIR="/tmp/mariadb-restore"
DATADIR="/var/lib/mysql"
TS="$(date '+%F_%H-%M-%S')"
LOGFILE="$BACKUP_BASE/logs/restore_$TS.log"
MBACKUP_LOGFILE="$BACKUP_BASE/logs/restore_$TS.mariabackup.log"

log() {
    echo "[$(date '+%F %T')] $1" >> "$LOGFILE"
}

confirm() {
    echo -e "\n⚠️  This will overwrite your current MariaDB data directory: $DATADIR"
    read -p "👉 Is MariaDB stopped and do you want to proceed with restore? (yes/no): " confirm
    if [[ "$confirm" != "yes" ]]; then
        echo "❌ Aborted by user."
        exit 1
    fi
}

check_disk_space() {
    total_size=$(find "$FULL_BACKUP_DIR" "$INCREMENTAL_BASE_DIR" -type f -name '*.zst' -exec du -b {} + | awk '{sum += $1} END {print sum}')
    available_space=$(df -B1 "$WORKDIR" | awk 'NR==2 {print $4}')
    threshold=$((total_size * 10))

    log "Total backup size: $total_size bytes"
    log "Available WORKDIR space: $available_space bytes"

    if (( available_space < threshold )); then
        echo "⚠️  Warning: Less than 10x the compressed backup size is available in $WORKDIR"
        echo "Required: $threshold bytes, Available: $available_space bytes"
        read -p "Continue anyway? (yes/no): " answer
        if [[ "$answer" != "yes" ]]; then
            echo "❌ Aborted by user due to insufficient space."
            exit 1
        fi
    fi
}

# === MAIN EXECUTION ===

log "Starting restore process..."
mkdir -p "$WORKDIR"
cd "$WORKDIR" || exit 1

LATEST_FULL_ZST=$(find "$FULL_BACKUP_DIR" -type f -name '*.mbstream.zst' | sort | tail -n 1)

if [[ -n "$LATEST_FULL_ZST" ]]; then
    check_disk_space
    log "Detected compressed full backup: $LATEST_FULL_ZST"
    zstd -dc "$LATEST_FULL_ZST" | mbstream -x -C "$WORKDIR"
else
    log "❌ No full backup found."
    exit 1
fi

log "Preparing full backup..."
mariabackup --prepare --target-dir="$WORKDIR" &>> "$MBACKUP_LOGFILE"

mapfile -t INCS < <(find "$INCREMENTAL_BASE_DIR" -type f -name '*.zst' | sort)

for inc in "${INCS[@]}"; do
    inc_file_name=$(basename "$inc")

    INC_TMP="/tmp/restore_inc_$(basename "$inc" .zst)"
    mkdir -p "$INC_TMP"
    log "Decompressing incremental: $inc"
    zstd -dc "$inc" | mbstream -x -C "$INC_TMP"
    log "Applying incremental to full: $inc"
    mariabackup --prepare \
       --target-dir="$WORKDIR" \
       --incremental-dir="$INC_TMP" &>> "$MBACKUP_LOGFILE"
    rm -rf "$INC_TMP"

    if [[ -n "$TARGET_INC_FILE" && "$inc_file_name" == "$TARGET_INC_FILE" ]]; then
        log "Reached target incremental file: $TARGET_INC_FILE. Stopping here."
        break
    fi
done

confirm

log "Restoring backup to $DATADIR using mariadb-backup --copy-back --target-dir=$WORKDIR"
mv ${DATADIR}/ ${DATADIR}.save
mariadb-backup --copy-back --target-dir="$WORKDIR"
chown -R mysql:mysql "$DATADIR"
rm -rf "$WORKDIR"

log "✅ Restore complete. You can now start MariaDB."
echo "✅ Restore complete. You can now start MariaDB: sudo systemctl start mariadb"