Backing Up WordPress in Docker: Complete Script & Setup Guide

📍 Overview

This guide explains how to create a complete backup of a WordPress site running in Docker, covering both the database and uploaded media (including featured images).

⚙️ Docker Environment Summary

My Docker setup includes:

MariaDB container as the database service
WordPress container with files stored in the wp_data Docker volume
A custom backup script to automate full backups

📦 Backup Script

Below is the script used to perform the full backup:

#!/bin/bash

# === Settings ===
BACKUP_DIR="/mnt/usb/service_backup/wordpress_backup"
DATE=$(date +'%Y-%m-%d_%H-%M')
DB_CONTAINER="wordpress-db-1"
DB_NAME="wordpress"
DB_USER="wordpress"
DB_PASS="wordpress"
DB_BACKUP="$BACKUP_DIR/db_backup_$DATE.sql"
WP_BACKUP="$BACKUP_DIR/wp_data_$DATE.tar.gz"
WP_VOLUME="wp_data"
LOG_FILE="$BACKUP_DIR/backup_log_$DATE.txt"

# === Create backup directory if not exists ===
mkdir -p $BACKUP_DIR

# === Logging ===
exec > >(tee -a "$LOG_FILE") 2>&1

echo "🔄 Starting WordPress backup at $DATE..."

# === Check mount ===
if [ ! -d "$BACKUP_DIR" ]; then
    echo "❌ Backup directory $BACKUP_DIR not found. Is the SSD mounted?"
    exit 1
fi

# === Dump database ===
echo "📦 Dumping MySQL database..."
docker exec $DB_CONTAINER sh -c "exec mysqldump -u$DB_USER -p$DB_PASS $DB_NAME" > $DB_BACKUP

# === Backup wp_data volume ===
echo "🗃️ Backing up wp_data volume..."
docker run --rm -v $WP_VOLUME:/volume -v $BACKUP_DIR:/backup alpine tar czf /backup/wp_data_$DATE.tar.gz -C /volume .

# === Optional: Cleanup old backups (7+ days) ===
find "$BACKUP_DIR" -type f -mtime +7 -name "*.tar.gz" -delete
find "$BACKUP_DIR" -type f -mtime +7 -name "*.sql" -delete

echo "✅ Backup complete: $DATE"

🔍 What Gets Backed Up?

The script captures:

MySQL Database: All posts, pages, users, and metadata
WordPress Files (wp_data volume):
- Plugins, themes, core files
- All media uploads (e.g., featured images, PDFs, video, etc.)
- Customizations or configuration files inside /var/www/html

📂 Generated Files

Located in your backup directory (/mnt/usb/service_backup/wordpress_backup):

db_backup_YYYY-MM-DD_HH-MM.sql → MySQL dump
wp_data_YYYY-MM-DD_HH-MM.tar.gz → Full archive of WordPress files (includes media like featured images)
backup_log_YYYY-MM-DD_HH-MM.txt → Execution log

🚀 How to Run

./wordpressbackup.sh

Ensure it’s executable:

chmod +x wordpressbackup.sh

⏳ Schedule Automatic Backups

To run every day at 2am:

crontab -e

Add:

0 2 * * * /path/to/wordpressbackup.sh

🚧 Optional: Restore Guide

To restore:

Extract the tar archive back into the Docker volume
Import the .sql file into the running MySQL container

Let me know if you’d like this included as a section.