Day17 of #90DaysOfDevOps Challenge

Dockerfile:

Instead of manually creating docker images by running multiple commands one by one, we can write a script where we can specify everything required for our image, and run one command to build the whole image.

Each command in dockerfile adds layers to create a docker image.

Here are some of the most commonly used commands in a Dockerfile:

• FROM: Specifies the base image required for our new image.
• RUN: Executes a command in the image during the building of the image, like installing packages.
• COPY: Copies files from the host machine to the image.
• ENV: Sets an environment variable in the image.
• EXPOSE: Specifies the ports that should be exposed on the container.
• CMD: Executed by container by default, when we launch the image to run the container.

Tasks:

1. Create a Dockerfile for a simple web application (e.g. a Node.js or Python app).

Python application cloned: https://github.com/shreys7/django-todo

The steps to run the application locally are explained in the above link. I am just creating the dockerfile for the same steps.

Dockerfile:

FROM python:3

RUN pip install Django==4.2.2

COPY . .

RUN python manage.py migrate

CMD ["python", "manage.py", "runserver", "0.0.0.0:8005"]        

2. Build the image using the Dockerfile and run the container.

Build the image -

docker build . -t todo-app        

Run the Container -

3. Verify that the application is working as expected by accessing it in a web browser.

4. Push the image to a public or private repository (e.g. Docker Hub ).

Firstly, I renamed the image to push in my docker hub repo.

sudo docker tag old:tag new:tag        

Now, while pushing I got access denied so I first logged in and then pushed the image.

sudo docker login
sudo docker push imagename        

The image is successfully pushed.

Thank you for reading! ??