title: docker: executable file not found in $PATH
body: <p>I have a docker image which installs <code>grunt</code>, but when I try to run it, I get an error:  </p>
  
  <pre><code>Error response from daemon: Cannot start container foo_1: \
      exec: "grunt serve": executable file not found in $PATH
  </code></pre>
  
  <p>If I run bash in interactive mode, <code>grunt</code> is available.</p>
  
  <p>What am I doing wrong?</p>
  
  <p>Here is my Dockerfile:</p>
  
  <pre><code># https://registry.hub.docker.com/u/dockerfile/nodejs/ (builds on ubuntu:14.04)
  FROM dockerfile/nodejs
  
  MAINTAINER My Name, me@email.com
  
  ENV HOME /home/web
  WORKDIR /home/web/site
  
  RUN useradd web -d /home/web -s /bin/bash -m
  
  RUN npm install -g grunt-cli
  RUN npm install -g bower
  
  RUN chown -R web:web /home/web
  USER web
  
  RUN git clone https://github.com/repo/site /home/web/site
  
  RUN npm install
  RUN bower install --config.interactive=false --allow-root
  
  ENV NODE_ENV development
  
  # Port 9000 for server
  # Port 35729 for livereload
  EXPOSE 9000 35729
  CMD ["grunt"]
  </code></pre>