sqlite3无法使用flask和docker打开数据库文件

Question

我有一个后端项目，最终结果存储在fragrant_detection.db中。我正在尝试使用 Flask 和 docker，但似乎无法让所有东西运行起来。

这是我的文件树

DE-Project/
│
├── .dockerignore
├── docker-compose.yaml
├── Dockerfile.train_model
├── Dockerfile.producer
├── Dockerfile.consumer
├── Dockerfile.frontend
│
├── shared/
│   └── requirements.txt
│   └── kaggle.json
│
├── train_model/
│   ├── train_model.py
│   └── functions.py
│
└── make_predictions/
│   └── producer.py
│   └── consumer.py
│   └── functions.py
│   └── fraud_detection.db
└── frontend/
    ├── app.py
    ├── test.py
    └── templates/
        └── index.html

这是烧瓶应用程序.py

from flask import Flask, render_template
import sqlite3
import os

app = Flask(__name__)

# Set the path to the templates folder explicitly
template_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'templates')
app.template_folder = template_path

# Get the absolute path to the directory containing this script
script_dir = os.path.dirname(os.path.abspath(__file__))

# Construct the absolute path to the database file
db_file_path = os.path.join(script_dir, 'make_predictions/fraud_detection.db')

@app.route('/')
def index():
    # Connect to the SQLite database using the absolute path
    conn = sqlite3.connect(db_file_path)

    # Create a cursor object to execute SQL queries
    cur = conn.cursor()

    # Execute a query to fetch all entries (assuming your table is named 'potential_fraud')
    sqlite_select_Query = "SELECT * FROM potential_fraud LIMIT 10;"

    # Execute the query
    cur.execute(sqlite_select_Query)

    # Fetch all the entries
    record = cur.fetchall()

    # Close the database connection
    conn.close()

    # Render the HTML template with the entries
    return render_template('index.html', entries=record)

if __name__ == '__main__':
    # Run the Flask app on port 5000

这是我的 Dockerfile：

# Use an official Python runtime as a parent image
FROM python:3.8

# Set the working directory to /app
WORKDIR /app

# Copy the current directory contents into the container at /app
COPY . /app

# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt

# Expose port 5000 to the outside world
EXPOSE 5000

# Run app.py when the container launches
CMD ["python", "app.py"]

当我在 docker 中运行它时，通过本地主机访问它时出现此错误：

  File "app.py", line 20, in index
    conn = sqlite3.connect(db_file_path)
sqlite3.OperationalError: unable to open database file

据我所知，当文件路径出现问题时通常会发生此错误。我用 test.py 测试了连接，效果很好：

import sqlite3

conn = sqlite3.connect('make_predictions/fraud_detection.db')
cur = conn.cursor()

sqlite_select_Query = "SELECT * FROM potential_fraud LIMIT 1;"
cur.execute(sqlite_select_Query)
record = cur.fetchall()
print(record)
cur.close()

conn.close()
print("The SQLite connection is closed")

我的 app.py 中有什么错误吗？也许是我的 Dockerfile 或者两者都有？

Answer 1

我设法解决了我的问题。诀窍，或者说我的解决方案，是将数据库放入共享驱动器中。我在 docker-compose、consumer.py 和前端中指定了它。这有效。我想更好的解决方案是在完全独立的容器中设置真正的数据库。但这目前有效:)