> For the complete documentation index, see [llms.txt](https://docs.duplocloud.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.duplocloud.com/docs/automation-platform/overview/quick-start/quick-start-ecs-services/step-4-create-app-via-ecs.md).
# Step 4: Create a Task Definition for an Application
You enabled ECS cluster creation when you created the [Infrastructure](/docs/automation-platform/overview/quick-start/step-1-infrastructure.md). In order to create a Service using ECS, you first need to create a [Task Definition](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definitions.html) that serves as a blueprint for your application.
Once you create a Task Definition, you can run it as a Task or as a Service. In this tutorial, we run the Task Definition as a Service.
*Estimated time to complete Step 4: 10 minutes.*
## Prerequisites
Before creating an RDS, verify that you completed the tasks in the previous tutorial steps. Using the DuploCloud Portal, confirm that:
* An [Infrastructure and Plan](/docs/automation-platform/overview/quick-start/step-1-infrastructure.md) exist, both named **NONPROD**.
* The **NONPROD** infrastructure has [ECS **Enabled**](/docs/automation-platform/overview/quick-start/step-1-infrastructure.md#check-your-work).
* A Tenant named [**dev01** has been created](/docs/automation-platform/overview/quick-start/step-2-tenant.md).
## Creating a Task Definition
1. In the **Tenant** list box, select the **dev01 Tenant.**
The DuploCloud Tenant list box with dev01 selected
2. Navigate to **Cloud Services** -> **ECS**.
3. In the **Task Definition** tab, click **Add**. The **Add Task Definition-Basic Options** area displays.
The Add Task Definition-Basic Options area
4. In the **Name** field, enter `sample-task-def`.
5. From the **vCPU** list box, select **0.5 vCPU**.
6. From the **Memory** list box, select **1 GB**.
7. Click Next. The **Advanced Options** area displays.
The Add Task Definition-Advanced Options page
8. In the **Container - 1** section, enter **Container Name** `sample-task-def-c1`.
9. In the **Image** field, enter `duplocloud/nodejs-hello:latest`.
10. In the **Port Mappings** section, in the **Port** field, enter `3000`. Port mappings allow containers to access ports for the host container instance to send or receive traffic.
11. Click **Create**.
---
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