title: Docker-Compile how indicate the directory
body: <p>I need to create a container image for python. I have created a Dockerfile and docker-compose.yml. I build the image, but the wrong directory is set for the project. I see the following error:</p>
  
  <pre><code>web_1    | python: can't open file 'manage.py': [Errno 2] No such file or directory
  </code></pre>
  
  <p>Structure of the project:</p>
  
  <pre><code>folder_project
  |
  |-django.testsite: manage.py and other files
  |-python: Docerfile
  |-docer-compose.yml
  </code></pre>
  
  <p>docker-compose.yml</p>
  
  <pre><code>version: '3'
  services:
   web:
    build: ./python
    ports:
     - "5000:5000"
   redis:
    image: "redis:alpine"
  </code></pre>
  
  <p>Dockerfile</p>
  
  <pre><code>FROM python:3
  
  RUN easy_install pip
  RUN pip install django==1.9.12
  
  ADD . /django.testsite
  WORKDIR /django.testsite
  
  CMD ["python", "manage.py", "runserver"]
  </code></pre>