Introduction

  • Conceptually, a virtual machine is a separate computer that runs with its own resources, operating system, and applications inside of a host operating system.
  • Containers are like lightweight virtual machines with some subtle but consequential differences.
  • Containers and virtual machines can address many of the same use cases.
  • Both virtual machines and containers are commonly used in academic research but containers are more popular.

Virtual machines using VirtualBox

  • The same VM can be copied and run on different computers
  • The execution state of VMs can be saved and restored at any time.
  • VM resources (e.g., CPUs, memory) can be changed, even after the VM is created. This allows controlling how much resources the VM can consume.

Basics of Containers with Docker

  • Containers are a way to provide a consistent environment for reproducible work.
  • Use docker pull to copy an image to your machine
  • Use docker start to start running a container
  • Use docker ps to check the status of running containers
  • Use docker stop to stop running a container

Creating Containers with Docker

  • Dockerfiles include instructions for creating a Docker image
  • The FROM command in a Dockerfile indicates the base image to build on
  • The CMD command in a Dockerfile includes commands to execute when a container starts running
  • The COPY command in a Dockerfile copies files from your local machine to the Docker image so they are available for use when the container is running