How to dockerize my flask web app with mysql database?Cannot connect mysql and cannot found render templete

Question

I am new to docker and trying to deploy this web app but cannot find solution. I'm running windows 10 and Docker Desktop. My docker-version is 19.03.5 and docker-compose version 1.25.4, build unknown.

My directory structure is:

  -docker-compose.yml
  -app
     -static
          js/
            script.js
          css/
              style.css
     -templates
            -index.html
     -app.py
     -dockerfile
     -requirements.txt
  -db
    -init.sql

docker-compose.yml

version: "2"
services:
app:
  build: ./app
  links:
    - db
  ports:
    - "5000:5000"

db:
  image: mysql:5.7
  ports:
    - "32000:3306"
  environment:
    MYSQL_ROOT_PASSWORD: root
  volumes:
    - ./db:/docker-entrypoint-initdb.d/:ro

dockerfile

FROM python:3.6
EXPOSE 5000
RUN mkdir -p /app
RUN ls /app
COPY static /app/static
COPY templates /app/templates
COPY app.py /app
COPY requirements.txt /app
WORKDIR /app
RUN pip install -r requirements.txt
CMD python app.py

requirements.txt

flask
mysql-connector

app.py

from flask import Flask, render_template, request
import mysql.connector
import os

app = Flask(__name__, template_folder='/templates', static_folder='/static')
@app.route('/')
def index():
    connection = mysql.connector.connect(
        user = 'root',
        password = 'root',
        host= 'db',
        port = '3306',
        database = 'test'
    )
    cursor = connection.cursor()
    cursor.execute("SELECT name from place")
    names = cursor.fetchall()
    return render_template('index.html', names = names)
if __name__ == '__main__':
    app.run(host='0.0.0.0')

My docker command is –

docker-compose up

Then trying to access http://0.0.0.0:5000/ but get mysql.connector.errors.InterfaceError: 2003: Can't connect to MySQL server on 'db:3306' and jinja2.exceptions.TemplateNotFound:

Answer 1

jinja2.exceptions.TemplateNotFound

Your flask folder paths are wrong, it should be either an absolute path like /app/templates and /app/static or a relative one like templates abnd static .

mysql.connector.errors.InterfaceError: 2003: Can't connect to MySQL server on 'db:3306'

If your init.sql script is correct then there is nothing wrong with your database, you just have let it initialize properly (wait for the mysqld: ready for connections message) before sending your first request.