title: Docker: preventing multiple docker images overwriting /usr/local/bin?
body: <p>Dockerfile One</p>
  
  <pre><code>FROM ubuntu
  FROM docker
  
  CMD ["ls", "/usr/local/bin"]
  </code></pre>
  
  <p>Then,</p>
  
  <pre><code>docker build -t test .
  docker run test
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>docker
  docker-containerd
  docker-containerd-ctr
  docker-containerd-shim
  docker-entrypoint.sh
  docker-init
  docker-proxy
  docker-runc
  dockerd
  modprobe
  </code></pre>
  
  <p>Added python image as below</p>
  
  <p>Dockerfile Two</p>
  
  <pre><code>FROM ubuntu
  FROM docker
  FROM python:2.7-slim
  
  CMD ["ls", "/usr/local/bin"]
  </code></pre>
  
  <p>Then, </p>
  
  <pre><code>docker build -t test .
  docker run test
  </code></pre>
  
  <p>Output</p>
  
  <pre><code>2to3
  easy_install
  easy_install-2.7
  idle
  pip
  pip2
  pip2.7
  pydoc
  python
  python-config
  python2
  python2-config
  python2.7
  python2.7-config
  smtpd.py
  wheel
  </code></pre>
  
  <p>Where did docker binaries go in the second test image?<br>
  How can i have both python and docker installed i.e. both python and docker executables in /usr/local/bin?</p>