title: Cannot connect to postgresql through sqlalchemy from different computer
body: <p>I think do not understand properly how does sqlalchemy works, I have tried to connect to postgresql running on some cloud server from my local computer:</p>
  
  <pre><code>db = create_engine('postgresql://ubuntu@172.23.160.212:5432/dbname')
  </code></pre>
  
  <p>but that causes the <strong>error</strong>:</p>
  
  <pre><code>Is the server running on host "172.23.160.212" and accepting
      TCP/IP connections on port 5432?
  </code></pre>
  
  <p>I have checked the port and host also exists.</p>
  
  <p>I thought I should connect to the host using ssh first:</p>
  
  <pre><code>with SSHTunnelForwarder((172.23.160.212, 22), ssh_username='ubuntu', remote_bind_address=(127.0.0.1, 3306)) as server:
      db = create_engine('postgresql://postgres@127.0.0.1:5432/dbname')
  </code></pre>
  
  <p>But that did not help.</p>