title: Difference between container port,host port and service port in dcos json in portMappings
body: <p>I am confused with what all these port signify container port,host port and service port in portMappings, below is my json</p>
  
  <pre><code>"portMappings": [
    {
      "containerPort": 9000,
      "hostPort": 9000,
      "labels": {
        "VIP_0": "/app2n:9000"
      },
      "protocol": "tcp",
      "servicePort": 10101
    }
  ]
  </code></pre>