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Dockerzie Flask Application

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Docker Clash Course

[start]
sudo systemctl start docker (debian based)
sudo service docker {stop|start|restart} (centos)

[build]
docker build -t whois-api:latest .

[List container]
docker ps -a  ## list all
docker ps -l ## list latest image

[List image]
docker image ls

[remove]
docker rmi -f $(docker images -f "dangling=true" -q) ## daggling images

Docker Intro

• Make sure you have installed docker and docker-compose. Verify your installation by checking their version

• Add the Dockerfile

## we choose alpine for the sake of tiny size
FROM python:3.7-alpine

RUN pip3 install gunicorn ## wsgi server in your container

## choose 'app' as workdir. Docker will create if it doesn't exists
WORKDIR /app

# copy just the requirements.txt first to leverage Docker cache
COPY ./requirements.txt /app/requirements.txt
RUN pip3 install -r /app/requirements.txt

COPY . /app

## define the port you will be using
EXPOSE 5000

Read Dockerfilereference documentation to learn more about these keywords.

To learn more about Alpine OS apk command read Alpine Linux package management wiki.

Leveraging Docker build cache documented in Dockerfile Bestpractice

Build the image

docker build -t flask-tutorial:0.0.1 .

- -t: to tag your image name - . : current dir (bash syntax)

Running the container

For the sake of ease, we will use docker-compose to run the container.

Note

Please discuss with your team, what port you will be using and what OS variable that you need (if you use environment keyword)

Then, add the appropriate docker-compose.yml file:

## remove anyline like this, I am just a description

version: '3'
services:
  whois: ## your container name
    image: flask-tutorial:0.0.1 ## your image name (that you built earlier) with the tag
    ports: ## the port on your `HOST:CONTAINER`
        - "5000:5000"
    environment: ## discuss with your team what to put here
      - APP_HOST=0.0.0.0
      - APP_PORT=5000
      - WHOIS_KEY=fakekey123
    command: sh run.sh server production

Read Docker Compose documentation to learn more about these keyword.

Run the app when everything ok

$ docker-compose up