title: Create networks automatically in Docker Compose
body: <p>When using custom networks in Docker like</p>
  
  <pre><code>networks:
    default:
      external:
        name: service-tier
  </code></pre>
  
  <p>And try to run that, I´m getting the error</p>
  
  <blockquote>
    <p>ERROR: Network service-tier declared as external, but could not be
    found. Please create the network manually using <code>docker network create
    service-tier</code> and try again.</p>
  </blockquote>
  
  <p>Is it possible to create networks automatically with docker-compose or is there no other way than creating them manually first?</p>