It wasn’t long ago that we looked at easily creating Docker containers from the command line so you could just easily spin up a virtual environment for development. Wouldn’t it be nice if you could do the same for virtual machines? You can. Using Multipass from Canonical, the makers of Ubuntu, you can easily spin up virtual machines under Linux, Mac, or Windows. Granted, most of the virtual machines in question are variations of Ubuntu, but there are some additional images available, and you can create your own.
Once you have it installed, starting up a new Ubuntu instance is trivial. If you have a set configuration, you can even set up predefined setups using a YAML file.
Installation
The process varies by platform, but on Ubuntu, installing Multipass is as easy as:
sudo snap install multipass
You should be sure that you are on a computer that can support virtual machines. The /proc/cpuinfo file should have a vmx or svm flag (actually, several of them; one for each core).
Catalog
You can see all the images available by running:
multipass find
Naturally, most of the images are Ubuntu versions, although there are a few other appliances like anbox and nextcloud available.
Suppose you want to do some testing in a Ubuntu bionic (18.04) instance. You can launch a default instance by issuing the command:
multipass launch bionic
However, you usually want a little more control since the default is one CPU core, a gigabyte of RAM, and 5G of disk storage. Say you want 4 CPUs, 6G of RAM, and a 10G disk. You can also provide a name for the virtual machine:
multipass launch -c 4 -m 6G -d 10G -n hackaday-vm bionic
On the Run
Once you have a bunch of virtual machines, you might want to see how they are doing:
multipass list
You can control them with start and stop. You can also delete a machine.
multipass stop hackaday-vm multipass start hackday-vm multipass stop hackaday-vm multipass delete hackaday-vm
Access
So what do you do with it? By default, the machine starts up with a private network that you can only access from the host machine. There are ways to route traffic around if you need to do that.
However, many times you just want a shell into the new machine. That’s easy:
multipass shell hackaday-vm
If you want to share data, you can mount a host folder into the virtual machine:
multipass mount ~/hackaday hackaday-vm
If you lose track of everything, you can ask about a particular machine:
multipass info hackaday-vm Name: hackaday-vm State: Running IPv4: 10.134.147.131 Release: Ubuntu 18.04.6 LTS Image hash: 5269cad5bc26 (Ubuntu 18.04 LTS) Load: 0.78 0.41 0.16 Disk usage: 1.2G out of 9.5G Memory usage: 143.2M out of 5.8G Mounts: /home/alw/hackaday => /home/alw/hackaday UID map: 0:default GID map: 0:default
It really is that simple. There are other commands available to run programs in a machine or set up networking. There’s also a GUI that sits in your system tray, but if you aren’t running virtual machines as your own user, that isn’t as useful to you.
Configuration
If you have things you always have to set up, you can automate that. You create a yaml file (known as a cloud init file) and set things up like users, packages, ssh keys, and the like. Note that the standard allows for several formats, but apparently Multipass only supports YAML.
The other thing you can do is use Packer to package a new image of your own. That’s a bit involved, but you can read the documentation to find out how.
Have you ever set up a development environment and then a few years later found out it was all broken because of updates? With virtual machines that never has to happen again. You can archive entire environments. This can be important in production environments when you need to go back to the exact way code was built to resolve a problem. It is also extremely important for safety-critical software where you sometimes have a requirement to be able to produce the exact same executable and prove that you can do it. Virtual machines make that much easier and Multipass is an easy way to create and use at least some kinds of virtual machines. The fact that it runs on multiple platforms itself is also a great feature.
It’s called Vagrant and has been around for years. Is Canonical becoming Apple?
Yes? They’re trying oh so hard to be a Linux walled garden.
Re vagrant. See https://www.vagrantup.com/
How can you have a “walled garden” on any machine where the user can bring up an administrative prompt and proceed to install or uninstall or modify anything they want? It doesn’t make any sense.
Right up there with “embrace, extend, extinguish” when referring to open-source.
There is only one “snap” store, controlled exclusively by one corporation.
No other 3rd-party stores are allowed nor is side-loading snaps from other sources.
The “snap” store is closed source.
“Snaps” update automatically whether you want them to or not.
Snapd is installed without permission or notice when some other software is installed (Chrome).
That all is an obvious attempt to create a walled garden.
I’d say there are way more than just one easy option already, and this multipass stuff does to me feel entirely like reinventing a perfectly functional wheel…
lxc/lxd is where it’s at for me. Throw in distbuilder – and it’s the danglies.
Do you use classic LXC (lxc-create, lxc-start, lxc-attach, …) or the newer LXD that loosely resembles Docker?
Classic LXC is where I typically dabble with unprivileged containers and custom networking on a CI environment. It’s certainly not a go-to “container solution” for newbies but it’s quite flexible, if you put in enough effort.
mkosi & systemd-nspawn
Classic LXC or the snap-based LXD?
I only use the former and typically use it for unprivileged containers on a CI environment.
It’s definitely not a tool I’d recommend for newbies but it can be quite flexible if you put in the effort needed.
Classic. I think it’s easy enough for a newbie to follow the getting started tutorials, the default configs are sane and the cli coherent.
i also love lxc (in preference to docker or lxd or virtualization) for my purposes but i’m surprised, or maybe disappointed, at the suggestion that it’s not as good a tool for beginners.
docker is an *awful* tool for beginners. it’s all gun and foot. there’s nothing to do but shoot and nothing to aim for but your feet. docker is *much* more complex than lxc, but everyone that thinks it is easy. it’s because they’re cut-and-pasting recipes, which inevitably winds up diffusing real host root access across your userbase in ways you don’t appreciate unless you really understand docker well beyond the newbie level.
lxc is a lot easier to get to the bottom of, and if you don’t bother to invest that effort, you will still typically not shoot yourself in the foot in this way. it’s true that there are fewer cut-and-paste tutorials for it, and that’s a flaw in our community. the tremendous proliferation of bad advice regarding docker is an even larger flaw in our community. oh well.
Yes! LXD immediately came to mind! Seems like they tried to simplify it a bit for the masses.
Big difference between VMS and VMs… I was confused when I started to read the article… the hazards of single case fonts in titles.
Indeed, though its only with your pointing out I realise it could have been about something other than what I expected this time. Seems like ambiguous acronyms should be banned from article titles.
This, maybe not even banned but at least defined at the first use!
I was a little disappointed aswell.
I hopped in here too thinking ‘easy’ VMS . Oh, not what I thought … I use Virtual Box and KVM and they work well… without snap too….
Coming from the perspective of a thrown-in Windows sys admin and most of my Linux experience being on Pi HW, I’ve recently built a ProxMox machine in my fledgling homelab. I know these are different types of HVs but I’d love to get input on how Canonical’s solution is comparable to Vagrant or something similar.
Also have a deep rooted dislike of snap installs, mainly from years of reading HaD comments. Again, would love to hear otherwise
Well in many ways there isn’t anything wrong with snap from a users perspective, the flaws are rather more about what it is and how most of us think stuff should be done over actual function.
As for the VM stuff its partly down to what do you really want to do. For instance on something like my Pi4 I’ll just invoke a script that directly calls qemu’s Arm variant with all the options required – super lightweight making the VM(s) really quite performant, really usable and can handle quite a few at once. And from the point of being very simple windows like the GUI on Virtual Machine Manager (libvirt based) is very nice and fully featured so you shouldn’t need CLI or config editing to create and use the VM. But there are quite a few options out there…
Clement Lefebre (maintainer of Linux Mint, a distro I’ve used daily for 6 years and am thrilled with) has good explanations of his distaste for Snap. Search “Linux Mint Snap” and you’ll find some good articles.
I was expecting a DEC VAX 11/780 emulator somehow easier than simh.
SMH.
yeah the last thing i wanted to do was read an article about yet another a brittle wrapper for boring VM tools. i clicked through for the DEC emulator. sigh.
For the last 20 years i have used qemu, most of the times with XPsp3 as os for the VM.
Qemu is great.
On Linux host, Virt-lightning https://github.com/virt-lightning/virt-lightning is faster then Multipass
Sound less flexible than Distrobox but possibly a little bit more secure.
Being snap makes it a complete non-starter.
agreed, no matter how potentially useful it is (reinvention of the wheel aside) I’m not going to consider it until it’s available as something else thanks to canonical’s previous poor behavior around snaps
Oh SNAP!
Crackle and Pop?
All these comments, and not a single Corbin Dallas / Lee look reference?
I was expecting better from you guys.
multipass