1.2.1 - Introduction to Docker

Last updated Jan 22, 2025

Youtube Video | ~24 min

https://www.youtube.com/watch?v=EYNwNlOrpr0&list=PL3MmuxUbc_hJed7dXYoJw8DoCuVHhGEQb&index=4&pp=iAQB

To work through this video you will need Docker 🐋 downloaded, a terminal window ▪️, and a code editor 📝 of choice (Pycharm for me). Please see the 'Introduction' section if you need more info.

✍️ In this video, we learn about what Docker is, get a pipeline overview, and learn about Docker container and Docker image. Then we work through an example of how to build an image with Docker.

⚒️ There is a supplemental video for those working on WSL found here: https://www.youtube.com/watch?v=Mv4zFm2AwzQ&list=PL3MmuxUbc_hJed7dXYoJw8DoCuVHhGEQb&index=17

What is...

Docker?

"Docker helps developers build, share, run, and verify applications anywhere — without tedious environment configuration or management." - https://www.docker.com/

Container?

"Simply put, containers are isolated processes for each of your app's components. Each component - the frontend React app, the Python API engine, and the database - runs in its own isolated environment, completely isolated from everything else on your machine." - https://docs.docker.com/get-started/docker-concepts/the-basics/what-is-a-container/

Image?

"If you’re new to container images, think of them as a standardized package that contains everything needed to run an application, including its files, configuration, and dependencies. These packages can then be distributed and shared with others." - https://docs.docker.com/get-started/introduction/build-and-push-first-image/

Tag?

"A tag is a custom, human-readable identifier that's typically used to identify different versions or variants of an image. If no tag is specified, latest is used by default." - https://docs.docker.com/get-started/docker-concepts/building-images/build-tag-and-publish-an-image/

https://blog.devgenius.io/docker-working-and-image-building-2d4901524617

Building a Container Image

Example code you want to deploy

Ex 1 py

import sys
import pandas as pd

print(sys.argv)
day = sys.argv[1]

# some pandas things

print(f'Finished for day {day}')

Ex 2 py

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

.https://docs.docker.com/build/concepts/dockerfile/

1

Dockerfile

Writing a DockerfileDocker Documentation

Supplemental Info on writing a Dockerfile

📝 Create a new 'Dockerfile' in your code editor. I recommend adding the Docker 'plug in' to your editor.

Ex 1

FROM python:3.12.8
RUN pip install pandas
WORKDIR /app
COPY pipeline.py pipeline.py

ENTRYPOINT ["python", "pipeline.py"]

Ex 2

# syntax=docker/dockerfile:1
FROM ubuntu:22.04

# install app dependencies
RUN apt-get update && apt-get install -y python3 python3-pip
RUN pip install flask==3.0.*

# install app
COPY hello.py /

# final configuration
ENV FLASK_APP=hello
EXPOSE 8000
CMD ["flask", "run", "--host", "0.0.0.0", "--port", "8000"]

.https://docs.docker.com/build/concepts/dockerfile/

🔖 https://docs.docker.com/reference/dockerfile/ - Dockerfile Instruction options i.e. 'FROM', 'RUN', etc.

2

Docker build

⬛ Terminal

docker build -t {image_name}:{tag_name} .

-t	{image_name}:{tag_name}	.
used to denote adding a tag	replace these values for your image_name and tag_name	a build command that uses the current directory (.) as a build context

Build, tag, and publish an imageDocker Documentation

3

Docker run

⬛ Terminal

docker run -it {image_name}:{tag_name}

👀 Note we will continue to build on this topic. We still need to talk about running containers, stopping containers, and viewing the front end of our containers.

🧹 Cleaning - be sure to open Docker Desktop and delete testing examples of your containers and images to free up space

Resources

My repo for this video can be found here

Not found

🔖 https://docs.docker.com/get-started/docker-overview/

🔖 https://github.com/HangenYuu/docker-cheatsheet

📚 I recommend working through the Docker site Intro & workshop if you're still confused on what Docker is

IntroductionDocker Documentation