Image Transcription: Meme
A photo of an opened semi-trailer unloading a cargo van, with the cargo van rear door open revealing an even smaller blue smart car inside, with each vehicle captioned as “macOS”, “Linux VM” and “Docker” respectively in decreasing font size. Onlookers in the foreground of the photo gawk as a worker opens each vehicle door, revealing a scene like that of russian dolls.
I’m a human volunteer content transcriber and you could be too!
Just need to put a JIT compiled language logo inside the blue car and caption it as “Containerise once, ship anywhere”.
Does docker really spin up a VM to run containers?
Yes, under windows and osx at least.
Is that still true? I use Linux but my coworker said docker runs natively now on the M1s but maybe he was making it up
I suspect they meant it runs natively in that it’s an aarch64 binary. It’s still running a VM under the hood because docker is really just a nice frontend to a bunch of Linux kernel features.
Maybe they just meant that it runs ARM binaries instead of running on Rosetta 2.
Docker requires the Linux kernel to work.
M1 is just worse arm. Since most people use x86_64 instead of arm, docker had to emulate that architecture and therefore had performance issues. Now you’ve got arm specific images that don’t require that hardware emulation layer, and so work a lot better.
Since that didn’t solve the Linux kernel requirement, it’s still running a VM to provide it.
Not making it up, but possibly confused. OCI containers are built on Linux-only technologies.
So that’s why it’s so memory hungry…
Try limiting it down to 2GB (there is an option in the Docker Desktop app). Before I discovered this option, the VM was normally eating 3-4GB of my memory.
On macos it does
When I was in school I once used a IOS emulator running inside a docker container of MacOS running on a linux machine. It works surprisingly smoothly.
Add a JVM just for the hell of it
A foldable bike in the trunk
Now add
dind
We’re reaching levels of containerization that shouldn’t even be possible!
Can someone please explain me like i am 5 what is docker and containers ? How it works? Can i run anything on it ? Is it like virtualbox ?
Is it like virtualbox ?
VirtualBox: A virtual machine created with VirtualBox contains simulated hardware, an installed OS, and installed applications. If you want multiple VMs, you need to simulate all of that for each.
Docker containers virtualize the application, but use their host’s hardware and kernel without simulating it. This makes containers smaller and lighter.
VMs are good if you care about the hardware and the OS, for example to create different testing environments. Containers are good if you want to run many in parallel, for example to provide services on a server. Because they are lightweight, it’s also easy to share containers. You can choose from a wide range of preconfigured containers, and directly use them or customize them to your liking.
A container is a binary blob that contains everything your application needs to run. All files, dependencies, other applications etc.
Unlike a VM which abstracts the whole OS a container abstracts only your app.
It uses path manipulation and namespaces to isolate your application so it can’t access anything outside of itself.
So essentially you have one copy of an OS rather than running multiple OS’s.
It uses way less resources than a VM.
As everything is contained in the image if it works on your machine it should work the same on any. Obviously networking and things like that can break it.
We need to go deeper and put a VM in linux
reminds me of a russian doll
I would not be surprised to learn this photo was taken in Russia.
But it’s Unix-like!
Uses a Linux VM for all the assignments anyway.
macOS is not unix-like, it is literally Unix.
it’s like an automotive turducken
Now run a KinD cluster inside that, with containers running inside the worker containers.
Does this count for Docker in an LXC on Proxmox as well?
Time to check out Podman.
Podman on MacOS is the same, is it not? Running a containers inside a VM?