#!/bin/bash

# This script backs up all running Docker containers.
# For each container, it creates a compressed archive file (.tar.gz) containing
# the container's state at the time of execution.
# Backups are stored in a directory called "backup_docker_container".
# Each backup file is named with the container name and the current date and time,
# making it easy to identify when the backup was taken.
# 
# Usage:
# 1. Save this script to a file, for example: backup_containers.sh
# 2. Make the script executable: chmod +x backup_containers.sh
# 3. Run the script: ./backup_containers.sh
# 
# Automation with Cron:
# You can automate the execution of this script and manage old backups with a Cron job:
#
# 1. To back up all Docker containers every Sunday at midnight:
#    0 0 * * 0 /root/backup_docker_container.sh
#
# 2. To delete backup files older than 14 days every day at 1 AM:
#    0 1 * * * find /root/backup_docker_container/* -mtime +14 -exec rm {} \;
# 
# Restoring a backup:
# To restore a Docker container from a backup, follow these steps:
# 
# 1. Uncompress the .tar.gz file:
#    gunzip /path/to/backup_docker_container/container_name_date.tar.gz
#
# 2. Create a Docker image from the .tar file:
#    cat /path/to/backup_docker_container/container_name_date.tar | docker import - new_image_name
#
#    This will create a new Docker image from the container's backup.
#
# 3. Start a new container from the restored image:
#    docker run -d --name new_container_name new_image_name
#
#    This will launch a new container based on the restored image.
#
# Note: This process does not restore Docker volumes. If your container used volumes,
# you will need to restore or recreate them separately.
#
# This script only backs up running containers at the time of execution.
# It exports only the container's file system (container content) and does not back up
# Docker volumes that may be mounted from the host.

# Backup directory
backup_dir="backup_docker_container"

# Create backup directory if it doesn't exist
mkdir -p "$backup_dir"

# Get current date and time
current_datetime=$(date +"%Y-%m-%d_%H-%M-%S")

# Get list of running Docker containers
containers=$(docker ps --format '{{.Names}}')

# Iterate through each container and create a compressed backup with container name and current date and time
for container in $containers
do
    echo "Backing up container $container..."
    docker export "$container" | gzip > "$backup_dir/${container}_${current_datetime}.tar.gz"
    echo "Backup of container $container completed."
done

# Indicate that the backup process is completed
echo "Backup process completed."