Lab : Build a docker image for Instavote frontend vote app

Voteapp is a app written in python. Its a simple, web based application which serves as a frontend for Instavote project. As a devops engineer, you have been tasked with building an image for vote app and publish it to docker hub registry.

Approach 1: Building docker image for voteapp manually

on the host

git clone https://github.com/schoolofdevops/vote
docker container run -idt --name dev -p 8000:80 python:alpine3.17 sh
cd vote
docker cp . dev:/app
docker exec -it dev sh

inside the container

cd /app
pip install -r requirements.txt
gunicorn app:app -b 0.0.0.0:80

Validate by accessing http://IPADDRESS:8000

on the host

docker diff dev

docker container commit dev docker.io/<username>/vote:v1

[where <username> should be replaced with your registry username ]

docker login

docker image push docker.io/<username>/vote:v1

Approach 2: Building image with Dockerfile

Change into vote directory which containts the source code. This assumes you have already cloned the repo. If not, clone it from https://github.com/schoolofdevops/vote

cd vote
ls

app.py  requirements.txt  static  templates

Add/create Dockerfile the the same directory (vote) with the following content,

FROM python:alpine3.17

WORKDIR /app

COPY . .

RUN pip install -r requirements.txt

EXPOSE 80

CMD  gunicorn app:app -b 0.0.0.0:80

Build image using,

 docker build -t docker.io/<username>/vote:v2 .

where, : your docker registry user/namespace. Replace this with the actual user

validate

docker image ls
docker image history docker.io/<username>/vote:v2
docker image history docker.io/<username>/vote:v1

docker container run -idt -P docker.io/<username>/vote:v2
docker ps

Check by connecting to your host:port to validate if vote web application shows up.

Once validated, tag and push

docker image tag docker.io/<username>/vote:v2 docker.io/<username>/vote:latest
docker login
docker push docker.io/<username>/vote
docker push docker.io/<username>/vote:v2