Docker components

The previous post about virtualization and containerization brought up some underlying technologies which Docker build containers on, including: namespaces – a Linux kernel mechanism to isolate resources. It allows a process to run within an isolated environment (mnt, pid, net, ipt, uts, user, cgroup) cgroups – a Linux kernel mechanism to limit resource usage of … Read moreDocker components

Host legacy application in Docker 2 of 2

My previous notes include some tricks in hosting legacy application in docker. This is a continuation from that work, after 1.5 months… Use Case I decided to use docker to host application for a good reason, and let me start with what this Java-based application does as a single process. When it is up it … Read moreHost legacy application in Docker 2 of 2

Host legacy application in Docker 1 of 2

This is my notes from containerizing a legacy application with Docker compose. We have to run multiple instances of our application because we’re unable to secure additional VMs for this single-VM education environment. The application is target of containerization, because it requires mass reconfiguration (around TCP port) to run multiple instances of the application. We … Read moreHost legacy application in Docker 1 of 2

Virtualization 4 of 4 – Networking

Virtual LAN (VLAN) Although VLAN emerged before virtualization and is technically not part of virtualization topic. I’d just like to start from here as a refresher. Suppose we have computers from finance department and computers from sales department all connected to a single layer-2 switch. There are at least three problems: 1) too many devices … Read moreVirtualization 4 of 4 – Networking

Virtualization 3 of 4 – Containers

In broad terms, virtualization of computing resource is about isolation of resources at different levels. We have covered hypervisor-based virtualization in the other post. In this article, we continue to dive into OS level virtualization. Remember again that the gist of virtualization is isolation of resource. To support OS level virtualization, the OS must have … Read moreVirtualization 3 of 4 – Containers

Docker network

Reading notes of “Docker DeepDive”. Docker networking is backed by libnetwork, which is an implementation of Container Network Model (CNM), an open-source pluggable architecture designed to provide networking to containers. Libnetwork also provides native service discovery and basic container load balancing solution. Docker networking also involves some drivers that extend the CNM model with specific … Read moreDocker network