title: apt-get not working in Dockerfile
body: <p><strong>ANSWER</strong>: I still don't know what was really wrong but after I restarted docker and ran it again (same dockerfile, same everything), it worked fine.</p>
  
  <p>I'm using Docker on Windows and my Dockerfile is</p>
  
  <pre><code>FROM ubuntu:15.04
  
  COPY . /src
  
  RUN apt-get update 
  RUN apt-get install -y nodejs 
  ...etc
  </code></pre>
  
  <p>but when I try to build the image I get</p>
  
  <pre><code>WARN[0001] SECURITY WARNING: You are building a Docker image from Windows against a Linux Docker host. All files and directories added to build context will have '-rwxr-xr-x' permissions. It is recommended to double check and reset permissions for sensitive files and directories
  
  ...
  
  Step 3: RUN apt-get -y update
   --&gt; Using cache
   ---&gt;ccd4120f98dd
  Removing intermediate container 255796bdef29
  Step 4: RUN apt-get install -y nodejs
   ---&gt; Running in f6c1d5a54c7a
  Reading package lists...
  Reading dependency tree...
  Reading state information...
  E: Unable to locate package nodejs
  INFO[0029] The command [/bin/sh -c apt-get install -y nodejs] returned a non-zero code:100
  </code></pre>
  
  <p>apt-get works but when I try to put other apt-get install lines in those don't work either so it doesn't seem to be a problem with.</p>