title: Not enough entropy to support /dev/random in docker containers running in boot2docker
body: <p>Running out of entropy in virtualized Linux systems seems to be a common problem (e.g. <a href="https://stackoverflow.com/questions/4819359/dev-random-extremely-slow">/dev/random Extremely Slow?</a>, <a href="https://stackoverflow.com/questions/5633877/getting-linux-to-buffer-dev-random">Getting linux to buffer /dev/random</a>). Despite of using a hardware random number generator (HRNG) the use of a an entropy gathering daemon like <a href="http://www.issihosts.com/haveged/index.html" rel="noreferrer">HAVEGED</a> is often suggested. However an entropy gathering daemon (EGD) cannot be run inside a Docker container, it must be provided by the host.</p>
  
  <p>Using an EGD works fine for docker hosts based on linux distributions like Ubuntu, RHEL, etc. Getting such a daemon to work inside boot2docker - which is based on Tiny Core Linux (TCL) - seems to be another story. Although TCL has a extension mechanism, an extension for an entropy gathering daemon <a href="http://forum.tinycorelinux.net/index.php?topic=15650.0" rel="noreferrer">doesn't seem to be available</a>.</p>
  
  <p>So an EGD seems like a proper solution for running docker containers in a (production) hosting environment, but how to solve it for development/testing in boot2docker?</p>
  
  <p>Since running an EGD in boot2docker seemed too difficult, I thought about simply using /dev/urandom instead of /dev/random. Using /dev/urandom is a litte less secure, but still fine for most applications which are not generating long-term cryptographic keys. At least it should be fine for development/testing inside boot2docker. </p>