How to Back Up Docker Volumes Safely

1# Stop the container first (safest)
2docker compose stop
3
4# Backup a named volume
5docker run --rm \
6  -v myapp_data:/source:ro \
7  -v $(pwd)/backups:/backup \
8  alpine tar -czf /backup/myapp_data_$(date +%Y%m%d).tar.gz -C /source .
9
10# Restart
11docker compose start
12
13# Restore a backup
14docker run --rm \
15  -v myapp_data:/target \
16  -v $(pwd)/backups:/backup \
17  alpine sh -c "cd /target && tar -xzf /backup/myapp_data_20240115.tar.gz"

1# PostgreSQL backup (hot backup, no downtime)
2docker exec postgres pg_dumpall -U postgres > backup_$(date +%Y%m%d).sql
3
4# Or compressed
5docker exec postgres pg_dump -U postgres dbname | gzip > backup_$(date +%Y%m%d).sql.gz
6
7# MySQL backup
8docker exec mysql mysqldump -u root -p${MYSQL_ROOT_PASSWORD} --all-databases > backup.sql
9
10# MongoDB backup
11docker exec mongo mongodump --archive --gzip > backup_$(date +%Y%m%d).gz
12
13# Restore PostgreSQL
14cat backup.sql | docker exec -i postgres psql -U postgres
15
16# Restore MySQL
17cat backup.sql | docker exec -i mysql mysql -u root -p${MYSQL_ROOT_PASSWORD}

1services: 
2  # Your application
3  postgres: 
4    image: postgres:15
5    volumes: 
6      - postgres_data:/var/lib/postgresql/data
7
8  # Automated backup container
9  backup: 
10    image: prodrigestivill/postgres-backup-local
11    environment: 
12      - POSTGRES_HOST=postgres
13      - POSTGRES_DB=myapp
14      - POSTGRES_USER=postgres
15      - POSTGRES_PASSWORD=${DB_PASSWORD}
16      - SCHEDULE=@daily
17      - BACKUP_KEEP_DAYS=7
18      - BACKUP_KEEP_WEEKS=4
19      - BACKUP_KEEP_MONTHS=6
20    volumes: 
21      - ./backups:/backups
22    depends_on: 
23      - postgres
24
25volumes: 
26  postgres_data: 

1# Using rclone to sync backups to cloud storage
2# First, configure rclone: rclone config
3
4# Sync backup folder to remote
5rclone sync ./backups remote:docker-backups
6
7# Automated with cron (add to crontab -e)
80 3 * * * /usr/bin/rclone sync /home/user/backups remote:docker-backups
9
10# Using restic for encrypted, deduplicated backups
11restic init --repo s3:s3.amazonaws.com/bucket-name/backups
12restic backup --repo s3:s3.amazonaws.com/bucket-name/backups ./backups

1#!/bin/bash
2# backup.sh - Backup all Docker volumes
3
4BACKUP_DIR="/backups/docker"
5DATE=$(date +%Y%m%d_%H%M%S)
6RETENTION_DAYS=30
7
8# Create backup directory
9mkdir -p "$BACKUP_DIR"
10
11# Function to backup a volume
12backup_volume() {
13    local volume=$1
14    echo "Backing up $volume..."
15    docker run --rm \
16        -v "$volume":/source:ro \
17        -v "$BACKUP_DIR":/backup \
18        alpine tar -czf "/backup/${volume}_${DATE}.tar.gz" -C /source . \
19        && echo "  Success: ${volume}_${DATE}.tar.gz" \
20        || echo "  FAILED: $volume"
21}
22
23# Backup specific volumes
24backup_volume "myapp_postgres_data"
25backup_volume "myapp_redis_data"
26backup_volume "myapp_uploads"
27
28# Clean old backups
29find "$BACKUP_DIR" -name "*.tar.gz" -mtime +$RETENTION_DAYS -delete
30
31echo "Backup complete. Location: $BACKUP_DIR"

1# Create a test volume
2docker volume create test_restore
3
4# Restore backup to test volume
5docker run --rm \
6  -v test_restore:/target \
7  -v $(pwd)/backups:/backup \
8  alpine sh -c "cd /target && tar -xzf /backup/myapp_data_20240115.tar.gz"
9
10# Start a test container with the restored data
11docker run --rm -v test_restore:/data alpine ls -la /data
12
13# Clean up
14docker volume rm test_restore