构建 Python Flask 应用程序的 Docker 映像

Question

我正在尝试为 Python Flask 应用程序构建 Docker 映像，但遇到构建问题 - 所有文件都位于名为 web 的文件夹中 - 这是项目结构：

web/
    __init__.py
    app.py
    Dockerfile
    models.py
    requirements.txt

而app.py 目前看起来是这样的：

from flask import Flask


app = Flask(__name__)

@app.route("/")
def hello_world():
    return "Hello World!"


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

我从https://www.smartfile.com/blog/dockerizing-a-python-flask-application/借来了Dockerfile：

FROM ubuntu:14.04

# Update OS
RUN sed -i 's/# \(.*multiverse$\)/\1/g' /etc/apt/sources.list
RUN apt-get update
RUN apt-get -y upgrade

# Install Python
RUN apt-get install -y python-dev python-pip

# Add requirements.txt
ADD requirements.txt /webapp

# Install wsgi Python web server
RUN pip install uwsgi
# Install app requirements
RUN pip install -r requirements.txt

# Create app directory
ADD . /webapp

# Set the default directory for our environment
ENV HOME /webapp
WORKDIR /webapp

# Expose port 8000 for uwsgi
EXPOSE 8000

ENTRYPOINT ["uwsgi", "--http", "0.0.0.0:8000", "--module", "app:app", "--processes", "1", "--threads", "8"]

我正在尝试使用docker build --no-cache --rm -t flask-app 构建 Docker 映像，但它以错误消息结束：

Successfully installed uwsgi
Cleaning up...
 ---> 9bbc004212a3
Removing intermediate container 70ed8f07c408
Step 8/13 : RUN pip install -r requirements.txt
 ---> Running in f5e2eb59ffd1
Could not open requirements file: [Errno 2] No such file or directory: 'requirements.txt'
Storing debug log for failure in /root/.pip/pip.log
The command '/bin/sh -c pip install -r requirements.txt' returned a non-zero code: 1

Answer 1

我认为对你的 Dockerfile 做一个很小的改变就可以解决这个问题：

FROM ubuntu:14.04

# Update OS
RUN sed -i 's/# \(.*multiverse$\)/\1/g' /etc/apt/sources.list
RUN apt-get update
RUN apt-get -y upgrade

# Install Python
RUN apt-get install -y python-dev python-pip

# Add requirements.txt
# Create app directory
ADD . /webapp

# Install wsgi Python web server
RUN pip install uwsgi
# Install app requirements
# Full path to requirements
RUN pip install -r /webapp/requirements.txt

# Set the default directory for our environment
ENV HOME /webapp
WORKDIR /webapp

# Expose port 8000 for uwsgi
EXPOSE 8000

ENTRYPOINT ["uwsgi", "--http", "0.0.0.0:8000", "--module", "app:app", "--processes", "1", "--threads", "8"]

我刚刚添加了requirements.txt 的完整路径，这可以通过几种不同的方式完成，例如复制整个目录文件夹然后构建它。

Answer 2

在添加要求之前，我将Dockerfile 的初始行替换为

FROM ubuntu:latest
RUN apt-get update -y
RUN apt-get install -y python-pip python-dev build-essential

它成功构建了图像。

$ docker images
REPOSITORY          TAG                 IMAGE ID                CREATED             SIZE
flask-app           latest              32b81efb5719        2 minutes ago       644.9 MB
ubuntu              latest              104bec311bcd        5 weeks ago         129 MB
$
$ docker run -d flask-app
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS               NAMES
73ae8baa93c2        flask-app       "uwsgi --http 0.0.0.0"   6 seconds ago       Up 5 seconds        8000/tcp            lucid_heyrovsky
$
$ docker inspect --format '{{ .NetworkSettings.IPAddress }}' 73ae8baa93c2
172.17.0.2

所以当我尝试指向 URL http://172.17.0.2:8000/ 时，我什么也得不到。

Answer 3

添加

WORKDIR /webapp

之前

RUN pip install -r requirements.txt