Docker basics

Docker is an open platform for developing, shipping, and running applications. Docker enables you to separate your applications from your infrastructure so you can deliver software quickly.

3 Main Parts

• Dockerfile
• Dockerimage
• Dockercontainer

Dockerfile

In root folder, create a file 'Dockerfile'

create a Docker Image

Inside the docker file, create instruction to create DockerImage

• Basic dockerfile instruction

    From python:3

    ADD main.py .

    RUN pip install requests beautifulsoup4

    CMD [ "python", "./main.py" ] 
    

Advance Dockerfile instruction

    FROM python:3.8

    WORKDIR /fastapi-app

    COPY requirement.txt .

    RUN pip install -r requirement.txt

    COPY ./app ./app

    CMD ["python", "./app/main.py"]

• FROM python:3.8(pulls the image from docker hub)

• WORKDIR /fastapi-app or WORKDIR /usr/src/app

• COPY requirement.txt .

• RUN pip install -r requirement.txt or RUN pip install --no-cache-dir -r requirements.txt

• COPY ./app ./app or COPY . .

• CMD ["python", "./app/main.py"]

Build the container

• docker build -t dockername(-t: tags the image)

  Run the container

• docker run python-fastapi or

• docker run -t -i python-fastapi(-t: Pseudo terminal, -i: interactive)` or

• docker run -d -p 8000:8000 python-fastapi (-d, detached mode, -p: port mapping from host port to container port)

Make sure run specify port in your app as well, in last line uvicorn.run(app, port=8000, host="0.0.0.0")

To view the docker,

• docker ps(list all running container)
• docker exec -it dockerid /bin/sh

Now, you are inside your docker container structure.

Docker resources for Python

1. Folder tutorial_youtube It has basic docker app. Used code for sample from these github, and https://www.youtube.com/watch?v=bi0cKgmRuiA

2. Folder tutorial_advance_youtube from https://www.youtube.com/watch?v=bi0cKgmRuiA

3. Folder freeCodeCamp_tutorials from freeCodeCampe youtube

Tutorial to use Docker advance from youtuber:

Python Engineer

Using FASTAPI.

Tu run we can use 
uvicorn main:app --reload

Or another way, by importing uvicorn lib, 

And test it on localport.

If everything working, then pip freeze > requirement.txt

Then start Dockerizing