📦 Mastering MySQL Backups & Restores in Docker: A Real-World Guide

🔗 GitHub Repo: https://github.com/manueltechlabs/java-blog-project/tree/main

When you’re running a Spring Boot app with Docker, your data is everything. Here’s how I handle MySQL backups and restores — the reliable way

✅ Why Not Just Copy Volumes?

Docker volumes are great for persistence, but they’re not backups. Copying a live database volume risks corruption.

👉 Best practice: Use mysqldump and mysql — tools built for consistency.

✅ The Setup: Non-Root User + Dedicated Database

Docker Compose automatically creates the user and database:

yaml
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      environment:
  MYSQL_DATABASE: ${MYSQL_DATABASE}
  MYSQL_USER: ${MYSQL_USER}
  MYSQL_PASSWORD_FILE: /run/secrets/mysql_password
  MYSQL_ROOT_PASSWORD_FILE: /run/secrets/mysql_root_password

✅ This creates a non-root user with full access to only the specified database — secure and production-safe.

🔄 Backup: From Container to Host

Export your database to a .sql file on your host:

sh
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      docker exec database mysqldump \
  -u root \
  --password=$(cat ./secrets/mysql_root_password.txt) \
  $(cat ./secrets/mysql_database.txt) \
  > backup-$(date +%F).sql

This gives you a portable, human-readable snapshot.

🚀 Restore: From Host to Container

Need to migrate or recover? Rebuild the DB in one go:

sh
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      # First, ensure container is running
docker-compose up -d database

# Then import
cat backup.sql | docker exec -i database mysql \
  -u root \
  --password=$(cat ./secrets/mysql_root_password.txt) \
  $(cat ./secrets/mysql_database.txt)
  • 🔐 Your secrets stay secure — no hardcoded passwords.

🧠 Key Insights

  • No manual user setup needed — Docker’s MySQL image handles MYSQL_USER, MYSQL_DATABASE, and permissions automatically.
  • Backups are part of CI/CD — automate with cron or GitHub Actions.
  • Next step: Push .sql files to S3 or cloud storage — I haven’t done this yet, but it’s on my roadmap.

💡 Pro Tip

Always test your backups:

sh
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      docker run -d --name mysql-test -e MYSQL_ROOT_PASSWORD=test mysql:8
docker exec -i mysql-test mysql -u root -ptest -e "CREATE DATABASE IF NOT EXISTS test;"   
docker exec -i mysql-test mysql -u root -ptest test < backup.sql
# Check Data after import
docker exec mysql-test mysql -u root -ptest -e "USE test; SHOW TABLES;"
# Stop the running container
docker stop mysql-test
# Remove the container
docker rm mysql-test
# Remove the image
docker rmi mysql:8

If it works here, it’ll work in production.

🔗 GitHub Repo: https://github.com/manueltechlabs/java-blog-project/tree/main