python-application-docker

app.py

from flask import Flask, request
from pymongo import MongoClient
import redis
import config
import tasks


app = Flask(__name__)

mongo_client = MongoClient(config.MONGO_HOST, config.MONGO_PORT)
redis_client = redis.Redis(host=config.REDIS_HOST, port=config.REDIS_PORT)

@app.route("/")
def hello_world():
    return "<p>Hello, World!</p>"

@app.route("/mongo_health")
def mongo_health():
    db = mongo_client.test
    ok = db.command("ping").get("ok")
    return "<p>MongoDB health check: {}</p>".format(ok)

@app.route("/redis_health")
def redis_health():
    ok = redis_client.ping()
    return "<p>Redis health check: {}</p>".format(ok)   

@app.route('/send_mail', methods=['GET'])
def send_mail():
    email = request.args.get('email')
    tasks.send_mail_async.apply_async(args=[email], countdown=3)
    return "<p>Email sent to {}</p>".format(email)



if __name__ == "__main__":
    app.run(debug=True, host="0.0.0.0", port=config.APP_SERVER_PORT)

config.py

APP_NAME="app"
APP_SERVER_PORT = 5008


MONGO_HOST = "localhost"
MONGO_PORT = 27017

REDIS_HOST = "localhost"
REDIS_PORT = 6379

CELERY_BROKER_URL = "redis://localhost:6379/0"
CELERY_RESULT_BACKEDN = "redis://localhost:6379/0"

Dockerfile

FROM python:3.9.13-slim as  python-deps

RUN apt-get update -y && apt-get install -y gcc
WORKDIR /usr/app
RUN python -m venv /usr/app/venv
ENV PATH="/usr/app/venv/bin:$PATH"
COPY requirements.txt ./
RUN pip install --upgrade pip==20.1.1 && \
    pip install -r requirements.txt   && \
    rm requirements.txt


FROM python:3.9.13-slim
RUN apt-get update -y && apt-get install -y supervisor
RUN groupadd -g 999 python && \
    useradd -r -u 999 -m -g python ec2-user

# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
ENV HOME=/home/ec2-user
ENV APP_HOME=/home/ec2-user/python-app
WORKDIR $APP_HOME

COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
COPY . $APP_HOME
COPY --chown=ec2-user:python --from=python-deps /usr/app/venv /usr/app/venv
RUN ln -s /usr/app/venv /home/ec2-user/python-app/venv

RUN chown -R ec2-user:python $APP_HOME
ENV PATH="$APP_HOME/venv/bin:$PATH"

USER 999

ENTRYPOINT ["/home/ec2-user/python-app/start_server.sh"]

start_server.sh

#!/bin/bash

# prepare log files and 
touch logs/gunicorn-access.log
touch logs/gunicorn.log

# run celery worker in background
supervisord -c /etc/supervisor/conf.d/supervisord.conf


gunicorn -b 0.0.0.0:5008 \
         --timeout 300 \
         --access-logfile logs/gunicorn-access.log \
         --error-logfile logs/gunicorn.log \
         --capture-output \
         --access-logformat '%(t)s %(p)s %(h)s "%r" %(s)s %(L)s %(b)s "%{Referer}i" "%{User-agent}i"' \
         app:app \

exec "$@"

tasks.py

from celery import Celery
import config

celery_client = Celery(config.APP_NAME +"-worker", broker=config.CELERY_BROKER_URL)

@celery_client.task
def send_mail_async(data):
    print("Sending mail to {}".format(data))
    return "Mail sent to {}".format(data)