networkMode

The Docker networking mode to use for the containers in the task. The valid values are `none`, `bridge`, `awsvpc`, and `host`. If no network mode is specified, the default is `bridge`. For Amazon ECS tasks on Fargate, the `awsvpc` network mode is required. For Amazon ECS tasks on Amazon EC2 Linux instances, any network mode can be used. For Amazon ECS tasks on Amazon EC2 Windows instances, `<default>` or `awsvpc` can be used. If the network mode is set to `none`, you cannot specify port mappings in your container definitions, and the tasks containers do not have external connectivity. The `host` and `awsvpc` network modes offer the highest networking performance for containers because they use the EC2 network stack instead of the virtualized network stack provided by the `bridge` mode. With the `host` and `awsvpc` network modes, exposed container ports are mapped directly to the corresponding host port (for the `host` network mode) or the attached elastic network interface port (for the `awsvpc` network mode), so you cannot take advantage of dynamic host port mappings. When using the `host` network mode, you should not run containers using the root user (UID 0). It is considered best practice to use a non-root user. If the network mode is `awsvpc`, the task is allocated an elastic network interface, and you must specify a NetworkConfiguration value when you create a service or run a task with the task definition. For more information, see Task Networking in the Amazon Elastic Container Service Developer Guide. If the network mode is `host`, you cannot run multiple instantiations of the same task on a single container instance when port mappings are used.