title: Writing csv files to local host from a docker container
body: <p>I am trying to set up a very basic data processing project where I use docker to create an ubuntu environment on an EC2, install python, take an input csv, perform some simple data manipulation, then output the data to a new csv in the folder where the input was. I have been able to successfully run my python code locally, as well as on the ec2, but when I run it with the docker container, the data appears to be processed (my script prints out the data), but the results not saved at the end of the run. Is there a command I am missing from my dockerfile that is causing the results not to be saved? Alternatively, is there a way I can save the output directly to an S3 bucket?</p>
  
  <p><strong>EDIT:</strong> The the path to the input files is "/home/ec2-user/docker_test/data" and the path to the code is "/home/ec2-user/docker_test/code". After the data is processed, I want the result to be written as a new file in the "/home/ec2-user/docker_test/data" directory on the host. </p>
  
  <p>Dockerfile:</p>
  
  <pre><code>FROM ubuntu:latest
  
  RUN apt-get update \
      &amp;&amp; apt-get install -y --no-install-recommends software-properties-common \
      &amp;&amp; add-apt-repository -y ppa:deadsnakes/ppa \
      &amp;&amp; apt-get update \
      &amp;&amp; apt-get install -q -y --no-install-recommends python3.6 python3.6-dev python3-pip python3-setuptools \
      &amp;&amp; apt-get clean \
      &amp;&amp; rm -rf /var/lib/apt/lists/*
  
  VOLUME /home/ec2-user/docker_test/data
  VOLUME /home/ec2-user/docker_test/code
  
  WORKDIR /home/ec2-user/docker_test/
  
  COPY requirements.txt ./
  
  RUN cat requirements.txt | xargs -n 1 -L 1 python3.6 -m pip install --no-cache-dir
  
  COPY . .
  
  ENV LC_ALL C.UTF-8
  ENV LANG=C.UTF-8
  
  CMD python3.6 main.py
  </code></pre>
  
  <p>Python Script:</p>
  
  <pre><code>import pandas as pd
  import os
  from code import processing
  
  path = os.getcwd()
  
  def main():
      df = pd.read_csv(path + '/data/table.csv')
      print('input df: \n{}'.format(df))
      df_out = processing.processing(df)
      df_out.to_csv(path + '/data/updated_table.csv', index = False)
      print('\noutput df: \n{}'.format(df_out))
  
  
  if __name__ == '__main__':
      main()
  </code></pre>
  
  <p><strong>EDIT:</strong> I have been running the dockerfile with "docker run docker_test"</p>