> For the complete documentation index, see [llms.txt](https://data-engineering-zoomcamp-2025-t.gitbook.io/tinker0425/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://data-engineering-zoomcamp-2025-t.gitbook.io/tinker0425/module-1/1.2-docker-and-docker-compose/1.2.1-introduction-to-docker.md).

# 1.2.1 - Introduction to Docker

Last updated Jan 22, 2025

Youtube Video | \~24 min

{% embed url="<https://www.youtube.com/watch?v=EYNwNlOrpr0&list=PL3MmuxUbc_hJed7dXYoJw8DoCuVHhGEQb&index=4&pp=iAQB>" %}
<https://www.youtube.com/watch?v=EYNwNlOrpr0&list=PL3MmuxUbc_hJed7dXYoJw8DoCuVHhGEQb&index=4&pp=iAQB>
{% endembed %}

{% hint style="info" %}
To work through this video you will need Docker :whale2: downloaded, a terminal window :black\_small\_square:, and a code editor :pencil: of choice (Pycharm for me). Please see the '[Introduction](/tinker0425/introduction/introduction-and-set-up.md)' section if you need more info.
{% endhint %}

:writing\_hand: 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.

:hammer\_pick: 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...

{% tabs %}
{% tab title="Docker?" %}
"Docker helps developers build, share, run, and verify applications anywhere — without tedious environment configuration or management." - <https://www.docker.com/>
{% endtab %}

{% tab title="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/>
{% endtab %}

{% tab title="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/>
{% endtab %}

{% tab title="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/>
{% endtab %}
{% endtabs %}

{% embed url="<https://miro.medium.com/v2/resize:fit:1100/format:webp/1*tjTUpEi8h53-DMkweX2TDQ.png>" %}
<https://blog.devgenius.io/docker-working-and-image-building-2d4901524617>
{% endembed %}

### Building a Container *Image*

Example code you want to deploy

{% tabs %}
{% tab title="Ex 1 py" %}

```python
import sys
import pandas as pd

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

# some pandas things

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

{% endtab %}

{% tab title="Ex 2 py" %}

```python
from flask import Flask
app = Flask(__name__)

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

.<https://docs.docker.com/build/concepts/dockerfile/>
{% endtab %}
{% endtabs %}

{% stepper %}
{% step %}

### Dockerfile

{% embed url="<https://docs.docker.com/get-started/docker-concepts/building-images/writing-a-dockerfile/>" %}
Supplemental Info on writing a Dockerfile
{% endembed %}

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

{% tabs %}
{% tab title="Ex 1" %}

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

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

{% endtab %}

{% tab title="Ex 2" %}

```docker
# 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/>
{% endtab %}
{% endtabs %}

:bookmark: <https://docs.docker.com/reference/dockerfile/> - Dockerfile Instruction options i.e. 'FROM', 'RUN', etc.
{% endstep %}

{% step %}

### Docker build

:black\_large\_square:  Terminal

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

<table><thead><tr><th>-t</th><th width="226">{image_name}:{tag_name}</th><th>.</th></tr></thead><tbody><tr><td>used to denote adding a tag</td><td>replace these values for your image_name and tag_name</td><td>a build command that uses the current directory (<code>.</code>) as a build context</td></tr></tbody></table>

{% embed url="<https://docs.docker.com/get-started/docker-concepts/building-images/build-tag-and-publish-an-image/>" %}
{% endstep %}

{% step %}

### Docker run

:black\_large\_square: Terminal

```bash
docker run -it {image_name}:{tag_name}
```

{% endstep %}
{% endstepper %}

:eyes:  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.

:broom: 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

{% @github-files/github-code-block url="<https://github.com/Tinker0425/de-zoomcamp-my-work/tree/master/module-01/docker/video_1>" %}

:bookmark:  <https://docs.docker.com/get-started/docker-overview/>

:bookmark: <https://github.com/HangenYuu/docker-cheatsheet>

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

{% embed url="<https://docs.docker.com/get-started/introduction/>" %}


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