title: Haproxy DNS Based backends based on wildcards
body: <p>Now that we have a dynamic DNS resolving Backend with Haproxy 1.6, i've been wondering whether I can make resolving to endpoint to dynamic backends. Here's what I would be looking for:</p>
  
  <pre><code>resolvers docker
  nameserver dnsmasq 127.0.0.1:53
  
  defaults
  mode http
  log global
  option httplog
  
  frontend f_myapp
  bind :443
  default_backend b_myapp
  
  backend b_myapp
  server services *:443 check resolvers docker resolve-prefer ipv4
  </code></pre>
  
  <p>OR</p>
  
  <pre><code>server services [%Host]:443 check resolvers docker resolve-prefer ipv4
  </code></pre>
  
  <p>Having this would allow me not to have to touch haproxy's configuration but only use DNS to update the backend-routing.</p>
  
  <p>Thanks
  Alessandro</p>