Move docker volume to new vm . (Shutdown the stack / container first )

move_docker_volume.sh

#!/bin/bash

# Function to check if the required commands are available
function check_dependencies() {
  local dependencies=("docker" "scp" "ssh" "tar")
  for cmd in "${dependencies[@]}"; do
    if ! command -v $cmd &> /dev/null; then
      echo "$cmd is required but not installed. Please install it and try again."
      exit 1
    fi
  done
}

# Function to display available Docker volumes and let user pick one using 'select'
function select_docker_volume() {
  echo "Available Docker volumes:"
  volumes=($(docker volume ls --format '{{.Name}}'))

  if [ ${#volumes[@]} -eq 0 ]; then
    echo "No Docker volumes found."
    exit 1
  fi

  select volume_name in "${volumes[@]}"; do
    if [[ -n "$volume_name" ]]; then
      echo "You selected: $volume_name"
      break
    else
      echo "Invalid selection. Please try again."
    fi
  done
}

# Function to create a tarball of the volume
function backup_volume() {
  echo "Backing up the volume..."
  docker run --rm -v "$volume_name:/volume" -v "$(pwd):/backup" busybox tar czf "/backup/${volume_name}.tar.gz" -C /volume .
  echo "Backup complete: $(pwd)/${volume_name}.tar.gz"
}

# Function to transfer the tarball to the destination VM
function transfer_backup() {
  read -p "Enter the destination VM (user@hostname): " destination_vm
  read -p "Enter the destination path on the VM: " destination_path

  echo "Transferring the backup to $destination_vm..."
  scp "${volume_name}.tar.gz" "${destination_vm}:${destination_path}"
  
  if [ $? -ne 0 ]; then
    echo "Transfer failed."
    exit 1
  fi
  echo "Transfer complete."
}

# Function to restore the volume on the destination VM
function restore_volume_on_destination() {
  read -p "Do you want to restore the volume on the destination VM now? (y/n): " restore_confirm
  if [[ "$restore_confirm" == "y" || "$restore_confirm" == "Y" ]]; then
    echo "Restoring the volume on the destination VM..."
    ssh "$destination_vm" << EOF
      docker volume create "$volume_name"
      docker run --rm -v "$volume_name:/volume" -v "$destination_path:/backup" busybox tar xzf "/backup/${volume_name}.tar.gz" -C /volume
      echo "Volume restored on the destination VM."
EOF
  else
    echo "Backup transferred. You can manually restore it later."
  fi
}

# Main script
check_dependencies
select_docker_volume
backup_volume
transfer_backup
restore_volume_on_destination

How to Use the Script:

Save the script to a file called move_docker_volume.sh.

nano move_docker_volume.sh

Make the script executable by running:

chmod +x move_docker_volume.sh

Run the script:

./move_docker_volume.sh

What the Script Does:

1. Checks Dependencies: The script checks if required commands like docker, scp, ssh, and tar are available on your system.
2. Volume Selection: It lists the available Docker volumes and allows you to pick one.
3. Backup: It creates a compressed backup (tar.gz) of the selected Docker volume.
4. Transfer: The script transfers the backup file to the destination VM using scp.
5. Restoration: You can optionally restore the volume on the destination VM immediately after transfer using SSH.

Example of Volume Selection:

When you run the script, the terminal will show the list of available Docker volumes, and you can pick one by entering its corresponding number:

Available Docker volumes:
1) volume1
2) volume2
3) volume3
Select the number of the volume to move: 2
You selected: volume2

This script provides an easy-to-use, interactive way of selecting Docker volumes via the terminal and automating the migration of the Docker volume between VMs.

Note:

You might need to make volume external: true since the volume is created outside of docker compose on new server.