Task Definitions

To prepare your application to run on Amazon ECS, you create a task definition. The task definition is a text file, in JSON format, that describes one or more containers, up to a maximum of ten, that form your application.

It can be thought of as a blueprint for your application. Task definitions specify various parameters for your application. Examples of task definition parameters are which containers to use, which launch type to use, which ports should be opened for your application, and what data volumes should be used with the containers in the task. The specific parameters available for the task definition depend on which launch type you are using. For more information about creating task definitions, see Amazon ECS Task Definitions.

The following is an example of a task definition containing a single container that runs an NGINX web server using the Fargate launch type. For a more extended example demonstrating the use of multiple containers in a task definition, see Example Task Definitions.

    "family": "webserver",
    "containerDefinitions": [
            "name": "web",
            "image": "nginx",
            "memory": "100",
            "cpu": "99"
    "requiresCompatibilities": [
    "networkMode": "awsvpc",
    "memory": "512",
    "cpu": "256"