Docker, Ubuntu 18.04 python3.7.2: standard_init_linux.go:207: пользовательский процесс exec вызвал ошибку формата exec

Я пытаюсь настроить службы докеров по ссылке https://testdriven.io/courses/microservices-with-docker-flask-and-react/part-one-postgres-setup/

Код у меня уже есть:

Структура кода

docker-compose-dev.yml
services/
        users/
             manage.py
             Dockerfile-dev
             entrypoint.sh
             project/
                    __init__.py
                    config.py
                    db/
                      create.sql
                      Dockerfile

docker-compose.yml

version: '3.7'

services:

  users:
    build:
      context: ./services/users
      dockerfile: Dockerfile
    volumes:
      - './services/users:/usr/src/app'
    ports:
      - 5001:5000
    environment:
      - FLASK_APP=project/__init__.py
      - FLASK_ENV=development
      - APP_SETTINGS=project.config.DevelopmentConfig
      - DATABASE_URL=postgres://postgres:postgres@users-db:5432/users_dev  # new
      - DATABASE_TEST_URL=postgres://postgres:postgres@users-db:5432/users_test  # new
    depends_on:  # new
      - users-db

  users-db:  # new
    build:
      context: ./services/users/project/db
      dockerfile: Dockerfile
    ports:
      - 5435:5432
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres

manage.py:

from flask.cli import FlaskGroup

from project import app, db  # new


cli = FlaskGroup(app)


# new
@cli.command('recreate_db')
def recreate_db():
    db.drop_all()
    db.create_all()
    db.session.commit()


if __name__ == '__main__':
    cli()

Файл Docker:

# base image
FROM python:3.7.2-alpine

# new
# install dependencies
RUN apk update && \
    apk add --virtual build-deps gcc python-dev musl-dev && \
    apk add postgresql-dev && \
    apk add netcat-openbsd && \
    apk add bind-tools

# set working directory
WORKDIR /usr/src/app

# add and install requirements
COPY ./requirements.txt /usr/src/app/requirements.txt
RUN pip install -r requirements.txt

# new
# add entrypoint.sh
COPY ./entrypoint.sh /usr/src/app/entrypoint.sh
RUN chmod +x /usr/src/app/entrypoint.sh

# add app
COPY . /usr/src/app

# new
# run server
CMD ["/usr/src/app/entrypoint.sh"]

entrypoint.sh

echo "Waiting for postgres..."

while ! nc -z users-db 5432; do
  sleep 0.1
done

echo "PostgreSQL started"

python manage.py run -h 0.0.0.0

config.py

import os  # new


class BaseConfig:
    """Base configuration"""
    TESTING = False
    SQLALCHEMY_TRACK_MODIFICATIONS = False  # new


class DevelopmentConfig(BaseConfig):
    """Development configuration"""
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL')  # new


class TestingConfig(BaseConfig):
    """Testing configuration"""
    TESTING = True
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_TEST_URL')  # new


class ProductionConfig(BaseConfig):
    """Production configuration"""
    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL')  # new

инициализация.py

import os
from flask import Flask, jsonify
from flask_restful import Resource, Api
from flask_sqlalchemy import SQLAlchemy


# instantiate the app
app = Flask(__name__)

api = Api(app)

# set config
app_settings = os.getenv('APP_SETTINGS')
app.config.from_object(app_settings)

# instantiate the db
db = SQLAlchemy(app)


# model
class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    username = db.Column(db.String(128), nullable=False)
    email = db.Column(db.String(128), nullable=False)
    active = db.Column(db.Boolean(), default=True, nullable=False)

    def __init__(self, username, email):
        self.username = username
        self.email = email


class UsersPing(Resource):
    def get(self):
        return {
        'status': 'success',
        'message': 'pong!'
    }

создать.sql

CREATE DATABASE users_prod;
CREATE DATABASE users_dev;
CREATE DATABASE users_test;

Файл Docker в папке db:

# base image
FROM postgres:11.2-alpine

# run create.sql on init
ADD create.sql /docker-entrypoint-initdb.d

Ожидается, что приложение будет успешно собрано и запущено на порту 5001. Однако журналы создания докеров дают следующий результат:

users_1     | standard_init_linux.go:207: exec user process caused "exec format error"
users-db_1  | 2019-05-09 15:07:37.245 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432
users-db_1  | 2019-05-09 15:07:37.245 UTC [1] LOG:  listening on IPv6 address "::", port 5432
users-db_1  | 2019-05-09 15:07:37.282 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
users-db_1  | 2019-05-09 15:07:37.325 UTC [18] LOG:  database system was shut down at 2019-05-09 15:07:35 UTC
users-db_1  | 2019-05-09 15:07:37.386 UTC [1] LOG:  database system is ready to accept connections