Dockers 101 – Series 2 of N – Using Dockerfile to Run a Tic Tac Toe Game in Python

Requirement:
- To run a Tic Tack Toe which is written in Python
Strategy:
- Docker uses a Dockerfile to define what all will be going in a container
- For above requirement we need the following:
  - a Python runtime
  - a working directory with the Python file
  - a command to execute the Python file
  - build the app
  - push the container to Docker Hub( you will need to create Docker Hub account and a repository under the account, Please visit hub.docker.com)
  - pull the image
  - run the container
Solution:
- Login to your Host machine(in my case a CentOS 7 machine)
- Make a directory “TicTackToe” and go to the directory – mkdir TicTackToe && cd TicTackToe
- Download my Python Tic Tack Toe game from here – wget https://testbucket786786.s3.amazonaws.com/python/TictacToe.py
- Now create a Dockerfile and copy the following content into it – nano Dockerfile
- Copy following content into the Dockerfile and save:
- The docker file has self explanatory explanations as what it is doing:
- ```
# Use an official Python runtime as a parent image
FROM python:2.7-slim # Set the working directory to /app
WORKDIR /app # Copy the current directory contents into the container at /app
ADD . /app # Run TicTacToe.py when the container launches
CMD ["python", "TicTacToe.py"]
```
- Now build the app(naeemstictactoelatest is the image name you want for this app)- docker build -t naeemstictactoelatest .
- Now check for the image name for your app and tag it for pushing it to Docker Hub
  - docker images # to check for image name
  - docker tag image username/repository:tag # for tagging
  - docker login # to login to the Docker hub
- Now push the image to Docker Hub
  - docker push mnaeemsiddiqui/naeemsrepo:naeemstictactoelatest
- Now that you have a docker image on docker hub, you can
  - pull the docker image – docker pull mnaeemsiddiqui/naeemsrepo:naeemstictactoelatest
  - to run your app – docker run -it mnaeemsiddiqui/naeemsrepo:naeemstictactoelatest
- Yay!!, you containerized your app and pushed it to docker hub and pulled that image and ran the container to run your application.