This ticket has two objectives:

• Refactor usages of `internalPort` for `routerPort`.
• Update how to enable the embedded router:
  • --routerPort option enables the embedded router and customize the port.

In a more detailed way, the solution to implement will have the following syntax:

• Enables embedded router with default port (27016) using command line.
  • mongod --shardsvr --routerPort --replSet rs0
• Enables embedded router and configures custom port (13000) using command line.
  • mongod --shardsvr --routerPort 13000 --replSet rs0
• Enables embedded router with default port using a configuration file.
  • Not possible.
• Enables embedded router (it needs a port) using a configuration file.

  {
      "sharding": {
          "clusterRole": "shardsvr"
      },
      "replication": {
          "replSetName": "rs0"
      }
      "net": {
          "routerPort": 27016
      }
  }