Docker containerization in NestJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Docker containerization?

Docker containerization is a way to package an application and its environment into a small, portable unit called a container. This container runs the app the same way everywhere, like a lunchbox carrying your meal exactly as you packed it.

beginner

Why use Docker with a NestJS application?

Using Docker with NestJS helps you run your app in a consistent environment on any machine. It avoids "it works on my computer" problems and makes deployment easier and faster.

beginner

What is a Dockerfile in the context of NestJS?

A Dockerfile is a simple text file with instructions to build a Docker image for your NestJS app. It tells Docker how to set up the environment, install dependencies, and start the app.

intermediate

How does Docker help with dependencies in NestJS projects?

Docker packages all dependencies inside the container, so you don't worry about installing Node.js or packages on the host machine. This keeps your app running smoothly everywhere.

beginner

What is the difference between a Docker image and a Docker container?

A Docker image is like a recipe or blueprint for your app environment. A Docker container is the running instance made from that image, like a cake baked from the recipe.

What file do you create to define how to build a Docker image for a NestJS app?

A Dockerfile

B package.json

C nest-cli.json

D docker-compose.yml

The Dockerfile contains step-by-step instructions to build the Docker image.

Which command runs a Docker container from an image?

A docker build

B docker push

C docker run

D docker pull

docker run starts a container from a Docker image.

Why is containerization helpful for deploying NestJS apps?

A It ensures the app runs the same everywhere

B It makes the app run slower

C It removes the need for code

D It replaces the database

Containers package the app and environment so it behaves consistently on any machine.

Which of these is NOT included inside a Docker container for a NestJS app?

A App dependencies

B App source code

C Node.js runtime

D Host machine's operating system

The container includes its own environment, not the host OS.

What does the command 'docker build .' do?

A Runs the container

B Builds a Docker image from the current folder

C Deletes all containers

D Lists running containers

It builds a Docker image using the Dockerfile in the current directory.

Explain how Docker containerization benefits a NestJS developer in simple terms.

Think about how a lunchbox keeps your meal safe and the same wherever you go.

Describe the role of a Dockerfile when containerizing a NestJS application.

It's like a recipe for making your app's container.