I'm currently diving into how Docker operates, and here's what I've gathered so far: Docker virtualizes part of the operating system but primarily works with a Linux kernel to keep things lightweight. I know there are solutions that create a substitute Linux kernel for running Docker containers on other operating systems, but ultimately, the containers are running in a Linux environment, right? I'm curious about deployment too—if I want to deploy an application in a non-Linux setting, would I need to redo all the dependency management? That seems counterproductive given Docker's purpose. Or can I only use the dependencies within the container, which might add unwanted overhead in deployment? I feel like I might be missing some key details, so any clarification would be greatly appreciated!
3 Answers
Regarding deployment in non-Linux environments, keep in mind that Docker containers aren't typically meant to be modified once deployed. They operate in isolation, but can communicate with each other and the external environment if needed.
It's important to note that Docker isn't really virtualizing anything. It uses Linux namespaces and cgroups for process isolation. If you're using Docker on a Linux host, you'll see the processes directly when you check with a tool like 'top'. But if you're on Windows or MacOS, Docker sets up a Linux VM, acting like a hypervisor to handle things. And if you go for Windows containers, you'll need to run Docker on a Windows host.
Actually, there are Windows base images available for Docker, so it's not strictly limited to Linux. The core Docker tech comes from the Linux world, so it has much better support there. But Windows containers are an option if you need them!
I noticed that the repo mentions host restrictions. It seems that the base image build needs to match the host build, or else it requires virtualization.