Creating a local directory to edit code after pulling new code - linux

Question

I have been stuck trying to figure out how to edit a python flask code after pulling from a Docker Hub repository on a different computer. I want to create a Folder in my Linux Desktop that contains all of the packages the image has when running as a container (Dockerfile, requirements.txt, app.py) that way I can edit the app.py regardless of what computer I have or even if my classmates want to edit it they can simply just pull my image, run the container, and be able to have a copy of the code saved on their local machine for them to open it using Visual Studio Code (or any IDE) and edit it. This is what I tried.
I first pulled from the Docker hub:
sudo docker pull woonx/dockertester1
Then used this command to run the image as a container and create a directory:
sudo docker run --name=test1 -v ~/testfile:/var/lib/docker -p 4000:80 woonx/dockertester1
I was able to create a local directory called testfile but it was an empty folder when I opened it. No app.py, dockerfile, nothing.
The example code I am using to test is from following the example guide on the Docker website: https://docs.docker.com/get-started/part2/
Dockerfile:
# Use an official Python runtime as a parent image
FROM python:2.7-slim
# 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 --trusted-host pypi.python.org -r requirements.txt
# Make port 80 available to the world outside this container
EXPOSE 80
# Define environment variable
ENV NAME World
# Run app.py when the container launches
CMD ["python", "app.py"]
requirements.txt:
Flask
Redis
app.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(__name__)
#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 __name__ == "__main__":
app.run(host='0.0.0.0', port=80)

Answer 1

What I do is;
First, I issue docker run command.
sudo docker run --name=test1 -v ~/testfile:/var/lib/docker -p 4000:80 woonx/dockertester1
At this stage, files are created in container. Then I stop the container (lets say container id is 0101010101) .
docker container stop 0101010101
What I do is simply copying those files from container to the appropriate directory on my machine by using :
docker cp <container_name>:/path/in/container /path/of/host
or
cd ~/testfile
docker cp <container_name>:/path/in/container .
So, You have the files craeted by docker run on you local host. Now you can use them with -v option.
sudo docker run --name=test1 -v ~/testfile:/var/lib/docker -p 4000:80 woonx/dockertester1
Normally, when you change a setting in your configuration, it should be enough to stop/start container to take in action.
I hope this approach solves your problem.
Regards