容器不将数据写入物理磁盘文件

Question

Python代码：

import datetime,os
data = ""
with open("D://PythonService//Test.txt", "w") as outFile:
    outFile.write(data + "Service started at - {}\n".format(datetime.datetime.now()))
    outFile.close()

Docker 文件

FROM python:latest
COPY requirements.txt .
RUN python -m pip install -r requirements.txt
WORKDIR /app
COPY . /app
CMD ["python", "WriteData.py"]

docker-compose.yml

version: '3.4'
services:
    newfoldercopy:
        image: newfoldercopy
        build:
          context: .
          dockerfile: ./Dockerfile
        volumes:
          - D:/PythonService:/var/lib/data/

我正在尝试将我的物理文件系统路径挂载到容器。但是容器不是在物理文件上写数据，容器是在容器虚拟文件上写数据。

Answer 1

据我了解

D:/PythonService - 本地路径

/var/lib/data/ - 容器内的路径

在 Python 代码中，您应该使用容器路径 (/var/lib/data/) 而不是本地路径 (D:/PythonService)

Answer 2

您的代码应该类似于 with open("/var/lib/data/Test.txt", "w") as outFile:

在容器内的 /var/lib/data 文件夹中写入的所有文件将可供 D:/PythonService

使用

volumes:
  - <host directory>:<container directory>

Answer 3

变化：

with open("D://PythonService//Test.txt", "w") as outFile:

至：

with open("/var/lib/data/Test.txt", "w") as outFile:

因为你的这一行 docker-compose.yml:

        volumes:
          - D:/PythonService:/var/lib/data/

也代替：

outFile.write(data + "Service started at - {}\n".format(datetime.datetime.now()))

您可以使用 f-string:

outFile.write(f'{data} Service started at - {datetime.datetime.now()}\n')

这使您的代码更具可读性。

据我了解，使用 with open() 会自动关闭您的文件，因此您可以更改 Python 代码：

with open("D://PythonService//Test.txt", "w") as outFile:
    outFile.write(data + "Service started at - {}\n".format(datetime.datetime.now()))
    outFile.close()

至：

with open("/var/lib/data/Test.txt", "w") as outFile:
    outFile.write(f'{data} Service started at - {datetime.datetime.now()}\n')

容器不将数据写入物理磁盘文件

Container not writing data to physical disk file

docker

docker-compose

docker-volume