cloud-init-examples

This repository includes some example of cloud-init YAML files for use with multipass in creating some virtual machines.

Examples

Included in this repository is a set of Bash script for starting, stoping and stats on a multipass VMs. These scripts are used in conjunction with a set of cloud init YAML files that describe a machine. The files are named in the form of MACHINE_NAME dash “-init.yaml”. You can create a copy of the *-init.yaml files named *-local.yaml and that will be used instead for a given machine name. In addition the startup Bash script, start-vm.bash accepts a machine “size” based on the the suffix part of the AWS EC2 machine names (e.g. t4g.nano suffix is “nano”). You can include this the first time you startup a machine to create a similarly size VM.

start-vm.bash minimal-dev nano: This is a minimal cloud init YAML just a demo of a configuration, it includes the Debian build-essentials package. It is roughly the spec of an AWS EC2 T4g.nano
start-vm.bash minimal-py small: This starts a “small” minimal Python 3 development machine. It is roughly the space of an AWS EC2 T4g.small
start-vm.bash invenio 2xlarge: This will create a machine configured to run Invenio RDM about the size of an EC2 T4g.xlarge instance
start-vm.bash dev-server medium: This is a server like development environment for Golang 1.18. This example creates a T4g.medium sized instance.

The next set provide the ability to run as a full GUI environment on macOS or Windows using the Microsoft Remote Desktop viewer or Remmina on Linux. The are based on the previous terminal oriented VMs but add the “ubuntu-desktop” and “xrdp” package to handle the remote displays. For you to use the GUI versions your VM accounts need to have a password associated with them. You can use the multipass shell command to get a shell and then use sudo passwd USERNAME to set the password for “USERNAME” (e.g. ubuntu, rsdoiel).

start-vm.bash dev-gui large: This will start a development virtual machine with the Ubuntu Desktop installed using the size similar to an AWS EC2 T4g.large instance.

The sizes recognized by start-vm.bash are nano, micro, tiny, small, medium, large, xlarge, 2xlarge. See https://aws.amazon.com/ec2/instance-types/t4 for the descriptions used to model these sizes. Look in the T4g section of the table

Multipass

Mulitpass is a tool for running and managing Ubuntu VMs. It is lighter weight then running VirtualBox, works across operating systems (e.g. Windows, macOS, Linux) and processor types (e.g. Intel an ARM). This means you can easily run VMs on Raspberry Pi or your favor macOS or Windows machine. The VM will match your host CPU architecture (i.e. you’re not running full emulation but using running as a Intel box on an Intel host or a ARM box on a Raspberry Pi or M1 Mac). VM’s can be easily create, started, stopped and destroy. The setup script is YAML rather than Ruby like with vagrant. There are a small number of commands to learn (i.e. multipass --help covers them all). Multipass is NOT as featureful as VirtualBox or Parallels but it does seem to be much lighter weight and the things you can adjust (e.g. RAM, CPU cores) are the ones you likely want to adjust anyway. It is focused on easily bringing up a server like environment for testing and development.

Common multipass commands

Get a list of VMs available

    multipass list

Set a VM as primary (e.g. a machine named “dev-server”) so you don’t have to provide a name with each command. If you want to access a non-primary VM then give it a name and pass the name in the command.

    multipass set client.primary-name=dev-server

Access the primary VM

    multipass shell

Access the “dev-server” VM

    multipass shell dev-server

Stop/Start the primary VM

    multipass stop
    multipass start

Stop/Start the “dev-server” VM

    multipass stop dev-server
    multipass start dev-server

Stop all the VM, delete them and purge them from disk.

    multipass stop --all
    multipass delete --all
    multipass purge

Move a file (e.g. staff-favorites.absh) to the “dev-server” VM

   multipass transfer staff-favorites.bash dev-server:.

Cloud Init Files

Cloud Init is a specification for bringing up a virtual machine (or container) using a YAML syntax. It can be relatively simple (see the minimal example) to elaborate (the dev example). You can specify things like users, packages to be installed, host files to be mounted or even shell scripts to run.

Minimal Py

The start-vm.bash minimal-py small scripts creates a minimal python development box described in minimal-py-init.yaml. It doens’t create users or install more than python3 and pip.

The Dev VM

This will create a VM named “dev-server”. It includes a more complete server development environment including support for Go version 1.18.x. It includes examples of installing packages via apt and snaps.

    start-vm.bash dev-server small

Access VM as Ubuntu user.

    multipass shell

You can also access via SSH using the IP addressed assigned.

The YAML file is dev-server-init.yaml.

The InvenioRDM VM

The InvenioRDM VM is similar to the dev VM except it installes a more limited number of dev packages and those required for InvenioRDM, such as imagemagick.

    start-vm.bash invenio-rdm 2xlarge focal

Like previous example access with the multipass shell command.

    multipass shell

A more complete exploration of running InvenioRDM is found in the InvenioRDM-setup

General purpose Bash scripts

I have provided three Bash scripts for starting/launching, getting info and stopping your multipass VM.

start-vm.bash - starts an existing or launches a new virtual machine based on a related cloud init YAML file. If you’re creating the machine pass a zie of nano, micro, small, medium, large, xlarge, or 2xlarge to create a machine with a similar profile to the AWS EC2 T4g sizes, see https://aws.amazon.com/ec2/instance-types/t4/
stats-vm.bash - will return information about the machine (i.e. it runs multipass info $MACHINE)
stop-vm-.bash - will stop the machine
remove-vm.bash - will delete and purge a machine

If you’ve defined a primary name for the machine the Bash scripts can be used without any additoinal parameters. If you provide a machine name as a parameter then the scripts will work with that machine name.

For creating new machines (aka multipass launch) the start-vm.bash script looks for a cloud init YAML file that defines the new machine. By default it first looks for the name $MACHINE-local.yaml and if that is not available it looks for $MACHINE-init.yaml. The *-init.yaml files provided in this repository are a good starting point but the cloud init support in multipass goes much further. The YAML file called dev-server-local.yaml is provided as an example of including full login setup for the developers in the DLD group of Caltech Library. This includes setting them up with sudo access, assigning them to additoinal groups and enabling login via SSH keys hosted on GitHub. By using the filename convension of *-init.yaml I can provide a general purpose machine definition while allowing for local modification via a version of the same file matching *-local.yaml.

Trouble shooting

On a Mac, you may not be able to mount local directories until you enable Full Disk Access for multipassd in Settings -> Security & Privacy -> Privacy.

I’ve run into some challenges on the M1 Mac as well as when using Cisco’s VPN. Here’s some helpful links to explore.

Trouble shooting networking errors on macOS

Where to go from here

We’ve create a few recipes you may find useful.