5 Containerizing applications

This chapter covers

Installing and using basic Docker commands
Running container images through the container registry
Making applications portable and runtimes version-controlled
Understanding hosting containers in registries
Building, running, and pushing containers using a local machine

Back in the late 1900s, we had to insert disks and cartridges into our devices to run software or play games. Continuously updating these applications was mostly impossible, so developers worked tirelessly to ensure these applications were locked and as bug-free as possible before their release. As you might imagine, this was a painfully slow process, especially compared to today’s standards.

These disks and cartridges could only be played or run on the devices they were designed for; Mario was played on Nintendo devices, and Windows computers ran Microsoft Word. In other words, the storage devices holding the software were tied directly to the operating system that could run the software. We still have the digital version of this today with app stores and digital downloads, with one major difference: the internet.

5.1 Hello World with Docker

5.1.1 Running your first container

5.1.2 Exposing ports

5.1.3 Entering a container

5.1.4 Stateless containers

5.2 Designing new container images

5.2.1 Creating a Dockerfile

5.2.2 Running your first container image

5.3 Containerizing Python applications

5.3.1 Version tags and a Python Dockerfile

5.3.2 Creating a Python Dockerfile

5.3.3 Ignoring unwanted files in Docker builds

5.3.4 Creating and running an entrypoint script

5.4 Containerizing Node.js applications

5.4.1 The Node.js entrypoint script and .dockerignore file

5.4.2 The Node.js Dockerfile

5.5 Pushing container images to Docker Hub

5.5.1 Your first push to Docker Hub

5.6 Summary