Requirements to Python Hello Website Image

Q

What are the requirements to build a Hello Website Docker image using the Python base image?

✍: FYIcenter.com

A

If you want to build simple Hello Website Docker image using a Python script, you need to prepare the following required files.

1. Create the Hello Website Python script.

$ mkdir python
$ cd python 

$ vi hello-web.py 

from flask import Flask
from redis import Redis, RedisError
import os
import socket

# Connect to Redis
redis = Redis(host="redis", db=0, socket_connect_timeout=2, socket_timeout=2)

app = Flask(__title__)

@app.route("/")
def hello():
    try:
        visits = redis.incr("counter")
    except RedisError:
        visits = "<i>cannot connect to Redis, counter disabled</i>"

    html = "<h3>Hello {name}!</h3>" \
           "<b>Hostname:</b> {hostname}<br/>" \
           "<b>Visits:</b> {visits}"
    return html.format(name=os.getenv("NAME", "world"), hostname=socket.gethostname(), visits=visits)

if __title__ == "__main__":
    app.run(host='0.0.0.0', port=80)

2. Create a text file, package.lst, to hold the required Python package names.

$ vi package.lst

Flask
Redis

3. Create the Dockerfile.

$ vi Dockerfile

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

# Set the working directory to /app
WORKDIR /app

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

# Install required packages
RUN pip install --trusted-host pypi.python.org -r package.lst

# Make port 80 available to the world outside this container
EXPOSE 80

# Define environment variable
ENV NAME World

# Run the Python script when the container launches
CMD ["python", "hello-web.py"]

As you can see, we provided in the following instructions in the Dockerfile:

  • Taking "python" image as the base.
  • Creating /app as the working directory on the container.
  • Copying files from the current directory to the /app directory on the container. This moves Python script, hello-web.py, and the required package list, package.lst, to the container.
  • Running the "pip" command to install required Python packages.
  • Exposing port 80 on the container.
  • Kicking off the Python script to listen to port 80 for HTTP requests.

See next tutorial to build a new Docker image using this Docker file.

 

Build and Run Python Hello Website Image

"python" - Python Docker Image

Building Docker Image with "docker build"

⇑⇑ Docker Container Platform - Tutorials

2019-05-25, 185👍, 0💬