title: Docker swarm - DNS service discovery, looking to internals
body: <p>First of all:<br>
  I have some poor experience with docker swarm (I mean I touch in production env). I read a lot of about it, and I know concepts like <code>veth</code>, <code>overlay</code>, <code>labels-pinning</code>, <code>vtep</code>, <code>bridge</code> and so on. I know also that <code>docker swarm</code> use some distributed key-value storage to deal with management of cluster.</p>
  
  <p>However, there is something that I don't understand:  service disorvery/DNS/resolving service name.  </p>
  
  <p>How does it work? Where is this DNS server placed? Who cares to resolve service names?<br>
  Is it possible to read the content of distributed key-value storage?</p>