title: Error response from daemon: Dockerfile parse error line 1: unknown instruction: #
body: <p>Im new to docker and trying to learn it.
  Im following this tutorial: <a href="https://docs.docker.com/get-started/part2/#apppy" rel="noreferrer">https://docs.docker.com/get-started/part2/#apppy</a></p>
  
  <p>So I installed Docker on Windows.
  Created 3 files, app.py, Dockefile and requirements.txt</p>
  
  <p>My docker file looks like this</p>
  
  <pre><code># 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
  ADD . /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
  CMD ["python", "app.py"]
  </code></pre>
  
  <p>When I run it in powershell </p>
  
  <pre><code>docker build -t friendlybuild .
  </code></pre>
  
  <p>But as result it gives this:</p>
  
  <pre><code>Error response from daemon: Dockerfile parse error line 1: unknown instruction: #
  </code></pre>
  
  <p>Like it doesnt work</p>
  
  <p>I have no idea why it doesnt work</p>