title: Dockerfile COPY from a Windows file system to a docker container
body: <p>I have a simple <strong>Dockerfile</strong>:</p>
  
  <pre><code>FROM php:7.1-apache
  LABEL maintainer="rburton@agsource.com"
  COPY C:/Users/rburton/code/MyAgsourceAPI /var/www
  </code></pre>
  
  <p>It is the last line that is giving me problems. I am copying from a Windows structure to a docker container (Linux I assume). When I build this image I get:</p>
  
  <pre><code>...
  Step 3/3 : COPY C:/Users/rburton/code/MyAgsourceAPI /var/www
  COPY failed: stat /var/lib/docker/tmp/dockerbuilder720374851/C:/Users/rburton/code/MyAgsourceAPI: no such file or directory
  </code></pre>
  
  <p>First, something is preventing the recognition that this is an absolute path and naturally if the path is pre-pended with <code>/var/lib/docker/tmp/dockerbuilder720374851</code> then the file will not be found. Second, I have tried <code>/</code> and <code>\</code> but all with the same result. Also the drive letter I suspect is confusing to docker. So the question is how do I copy files and folders (along with the contents) from a Windows folder to a docker container?</p>