davidh83110 / flask-app

Flask App and Helm Chart

Flask Application

This is a Flak RESTfulAPI. Please run the application and vivsit /swagger for API documentations.

• http://localhost:3000
• http://localhost:3000/health
• http://localhost:3000/metrics
• http://localhost:3000/swagger
  • Visit Swagger for more V1 API details.

🐳 Docker Registry is here -- davidh83110/flask-app

Table of Content

• Data Migration
• How to Run
  • Quick Run
    • Docker Compose
    • Kind and Helm Chart
  • Prerequisites
  • Setup Environment
  • Start Flask Application
    • In Gunicorn without Docker
    • In Gunicorn with Docker
    • Running in local with Kind and Helm Chart
  • Check Result
• Development
• CI/CD
• Versioning
• Logging

Data Migration

The /history API will require some history data in place so that it can return to user, so we have scripts/migrations.py here for helping to inject initial data. The script will be executed when we run scripts/entrypoint.sh in Docker environment.

If you are not in Docker environment, please run it manually before start the application.

cd scripts
python3 migrations.py

How to Run

This Page will only focus on Flask application, if you need any information about Helm or run in Kubernetes, please visit deploy/README.md.

Quick Run

Docker Compose

docker-compose up --build -d

• Hardcode the password in the docker-compose.yaml, it can also use docker-compose secret from file.

Kind and Helm Chart

cd ./deploy
sh ./startup.sh

• More information, please visit deploy/README.md.

Prerequisites

• Python >= 3.10
• Pipenv
• Docker
• Redis Server

Setup Environment

• Install Pipenv

  python -m pip install --upgrade pip
  pip install pipenv --no-cache-dir
  

• Install Dependencies

  pipenv install --system --deploy --ignore-pipfile
  

• Start Redis Locally

   docker run -p 6379:6379 -itd redis:alpine                  
  

Start Flask Application

In Gunicorn without Docker

gunicorn --bind 0.0.0.0:3000 \
            --access-logfile flask-app-gunicorn.log \
            --error-logfile flask-app-gunicron-error.log \
            --log-level debug \
            wsgi:app

In Gunicorn with Docker

• Build Docker Image

   export APP_VERSION=0.0.1
   docker build --build-arg APP_VERSION=$APP_VERSION --no-cache -t flask-app .
  

• Run Docker Container

  docker run -p 3000:3000 -it -e REDIS_HOST='172.17.0.1' flask-app
  

  • 172.17.0.1 is Docker default host network, I am assuming you have a Redis running in Docker.

Running in local with Kind and Helm Chart

please visit deploy/README.md.

• Helm Chart Home Page - https://davidh83110.github.io/flask-app

Check Result

After the applciation is started, you can always vivist the pages on browser -- http://localhost:3000 .

Development

Run under Pipenv Shell

pipenv install --deploy
pipenv shell
python3 main.py

or

pipenv install --deploy
pipenv run python3 main.py

Install PYPI packages with Pipenv

pipenv install flask ...
pipenv update

Run Unittest

pipenv shell
pytest

CI/CD

I use Github Actions to implement a simple CI/CD pipeline, which includes unittest, SAST evulation, docker build and push, and helm package and upload.

• Please visit ci-build.yaml.
• SAST tool - bandit
• We could possibly optimize the pipeline to be faster and comment some messages on the Pull Request, but I just ignore those things since it is a demo only.

The artifacts of this CI pipeline are --

• Docker Image on Docker Hub -- davidh83110/flask-app
• Helm Package on Github Pages

Versioning

I use a VERSION file to control the Application version, which will be the APP_VERSION when we build the Docker Image. But in real environment, I think we can do it with tags triggering, auto increament, or integrate with Jira/Github Project.

Logging

The access and error logs of Gunicorn/Flask will be shown as JSON format, it is better for most of the log streamer like Filebeat.