title: Where is the workdir folders in Docker?
body: <p>Im new to Docker and currently reading the docs as I go along. I also cant get my head around changing files in docker.</p>
  
  <p>I've created a docker file on my local iMac:</p>
  
  <p><strong>Dockerfile:</strong></p>
  
  <pre><code>from ubuntu:14.04
  
  # Install prerequisites
  run apt-get update &amp;&amp; apt-get install -y \
      build-essential \
      cmake \
      curl \
      git \
      libcurl3-dev \
      libleptonica-dev \
      liblog4cplus-dev \
      libopencv-dev \
      libtesseract-dev \
      wget
  
  # Copy all data
  copy . /srv/openalpr
  
  
  # Setup the build directory
  run mkdir /srv/openalpr/src/build
  workdir /srv/openalpr/src/build
  
  # Setup the compile environment
  run cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr -DCMAKE_INSTALL_SYSCONFDIR:PATH=/etc .. &amp;&amp; \
      make -j2 &amp;&amp; \
      make install
  
  workdir /data
  
  entrypoint ["alpr"]
  </code></pre>
  
  <p>That file is inside a folder called "foo": <code>foo/Dockerfile</code> Inside <code>foo</code> folder, I'm expected to see this folder path: <code>/srv/openalpr/src/build</code> but I see nothing. What is and where is that folder? I thought ubuntu would be installed there? Basically I need to <code>nano</code> some files in x location inside ubuntu. Where and how to do that?</p>