Multipass Docker VM Documentation¶

This guide explains how to use Multipass to launch and manage Docker containers within a virtual machine (VM). Each section provides step-by-step instructions for various tasks, from launching a Docker VM to linking it with the host machine and accessing Docker services.

1. Launch Docker VM with Multipass¶

To launch a new virtual machine running Docker, use the following command:

multipass launch --name docker-vm

This command launches a new Ubuntu instance named docker-vm. You can manually install Docker inside the VM or automate the process using a cloud-init script.

2. List Running Instances with Multipass¶

To check all running Multipass instances, use:

multipass list

Example Output:

Name                    State             IPv4             Image
docker-vm               Running           192.168.64.2     Ubuntu 22.04 LTS

3. Access the Docker VM Shell¶

To interact with the VM directly, enter its shell:

multipass shell docker-vm

Once inside, you can install Docker or manage configurations.

4. Launch a Docker VM with a Custom Name¶

Specify a custom name for the VM during launch:

multipass launch --name docker-vm

The --name flag assigns a custom name (docker-vm in this case).

5. View Available Multipass Images¶

To see available images for launching VMs:

multipass images

This lists all available images (e.g., Ubuntu versions).

6. Check Running Docker Containers¶

Once Docker is installed, check container status inside the VM:

docker ps

This lists all running Docker containers, including their names, statuses, and port mappings.

7. Access a Docker Container via Portainer¶

To access a Docker container from the host machine:

Find the VM's IP address:

sh multipass list

Map the container port (e.g., 9000) to the host. Access it via:

http://<VM-IP>:9000

Example:

http://192.168.64.2:9000

This allows access to the Portainer web interface running in the VM.

8. Link Host Machine with Virtual Machine¶

To facilitate file sharing, mount a host directory into the VM:

multipass mount /host/directory docker-vm:/vm/directory

This mounts /host/directory from the host into /vm/directory in the VM.

9. Execute Docker Commands in VM from Host¶

Run Docker commands directly from the host using multipass exec:

multipass exec docker-vm -- docker ps

This executes docker ps inside docker-vm and displays the output on the host.

10. Create a Docker Alias for Ease of Use¶

Simplify Docker commands by creating an alias in your ~/.bashrc or ~/.zshrc file:

alias docker="multipass exec docker-vm -- docker"

Now, run Docker commands as if they were local:

docker ps

This executes the commands inside docker-vm seamlessly.