Docker and Containers (1): Why Containers — The Problem VMs Didn't Solve

Fri, 16 Jun 2023 09:00:00 +0000

Every developer has heard the phrase “it works on my machine.” Virtual machines were supposed to fix that, and they did — at the cost of gigabytes of RAM, minutes of boot time, and an entire duplicate operating system per application. Containers asked a different question: what if we could isolate applications without duplicating the kernel?

The Actual Problem#

Consider deploying a Python web application. You need Python 3.11, specific pip packages, a particular version of libssl, and some system-level configuration. Your colleague’s app needs Python 3.9 and a conflicting libssl version. The staging server runs Ubuntu 20.04 while production runs Amazon Linux 2.

Cloud Computing (2): Virtualization Technology Deep Dive

Mon, 20 Feb 2023 09:00:00 +0000

Without virtualization, there is no cloud. Every EC2 instance, every Lambda invocation, every Kubernetes pod ultimately stands on the same trick: lying convincingly to an operating system about the hardware underneath it. This article walks the full stack — from the CPU instructions that make the trick cheap, through the four hypervisors that dominate the market, to the production-grade tuning knobs that decide whether your VMs run at 70 % or 99 % of bare metal.

Virtualization on Chen Kai Blog

Docker and Containers (1): Why Containers — The Problem VMs Didn't Solve

The Actual Problem#

Cloud Computing (2): Virtualization Technology Deep Dive