If the container is deleted, the changes you’ve made are deleted with it unless they are in turn committed to a new image. You can write to this container and make changes, but this does not affect the image.
Images do not have a state and do not change.Ĭontainer: a running instance of a Docker image. An image typically contains layered filesystems.
Image: an organized collection of files, configurations and installed programs, as well as a set of instructions (from the Dockerfile) as to how to execute those items.
The instructions are executed in the order they are written. There is a full glossary of terms that will come in handy if this is your first experience with Docker, but here are some of the basics that you need to know:ĭockerfile: the main set of instructions a user can execute to form a new Docker image, via the “docker build” command.
Docker is designed so that developers have all of the tools they need (code, runtime, system tools, system libraries) to install a piece of software on a server, regardless of the environment. Cloud infrastructure made it easy and cheap to get VMs, but we were still saddled with the frustrations of managing these little servers and updating them with each code deploy. In the past (and present), our applications ran on VMs, little virtual servers. If you want to see this process in action, you can watch my screencast of dockerizing the app. And you, too, can create a pull quote once we've dockerized this app. Pull quotes add emphasis to the most memorable parts of an article. What’s great about this app is that I can make my very important literary pieces into illustrated works of art. Now that I'm done with my first week, I’m going to walk you through step by step how to dockerize an app.įor this tutorial, I’ll be dockerizing Verge Pull Quote Generator, an HTML+JS application by Dave Schumaker. I started playing around with the concepts of containers and images and got up to speed quickly. Previously, I had worked as a front-end developer, for the most part without total knowledge of the environment my work was running in.
Confession: upon starting my job at Joyent as Documentation Editor, my experience with Docker amounted to hearing the word and having a vague understanding of what it means for the state of development.