title: Redis server enforcing AUTH, but was not configured to requirepass
body: <p>I have a Rails application that uses Redis for background jobs (via Resque). This has all been working fine in development and production (on a VM) for quite some time. Recently, when trying to access the resque-web Sinatra site in production to administer the background tasks, I was met with a <code>Internal Server Error</code> message. Looking at the web server log, I can see that the error is originating from Redis, as it seems to be expecting a password for authentication:</p>
  
  <pre><code>Redis::CommandError - NOAUTH Authentication required
  </code></pre>
  
  <p>Here's the strange part, my redis conf file (<code>/etc/redis/6379.conf</code>) does not have (and to my knowledge has never had) any authentication enabled (notice both lines are commented out):</p>
  
  <pre><code>...
  # If the master is password protected (using the "requirepass" configuration
  # directive below) it is possible to tell the slave to authenticate before
  # starting the replication synchronization process, otherwise the master will
  # refuse the slave request.
  #
  # masterauth &lt;master-password&gt;
  ...
  # Require clients to issue AUTH &lt;PASSWORD&gt; before processing any other
  # commands.  This might be useful in environments in which you do not trust
  # others with access to the host running redis-server.
  #    
  # This should stay commented out for backward compatibility and because most
  # people do not need auth (e.g. they run their own servers).
  # 
  # Warning: since Redis is pretty fast an outside user can try up to
  # 150k passwords per second against a good box. This means that you should
  # use a very strong password otherwise it will be very easy to break.
  #
  # requirepass foobared
  ...
  </code></pre>
  
  <p>If I try to restart the redis server, it won't let me without a password:</p>
  
  <pre><code>sudo /etc/init.d/redis_6379 restart
  Stopping ...
  (error) NOAUTH Authentication required.
  Waiting for Redis to shutdown ...
  Waiting for Redis to shutdown ...
  </code></pre>
  
  <p>So my immediate problem is that my Redis server has a password set and I don't know what it is. I need to get it working again.</p>
  
  <p>The second problem is that I have no idea how this password got set. The application is deployed on a DigitalOcean VM. Looking over the redis logs didn't show anything suspicious. I used the recommended SSH and custom port setup to provide a bit of access security, but of course it's never fully secure. This application is a side-project of mine and there is not really any sensitive information at stake. However, I do want to figure out what happened and stop it from happening again.</p>