Real-time AI Model Serving with ECS Task Definitions

Question

Pulumi · Accepted Answer

To set up a system for serving a real-time AI model using AWS ECS (Elastic Container Service), we will need to create a containerized environment where the AI model can run. AWS ECS is a container orchestration service that can launch, stop, and manage Docker containers on a cluster.

Here’s how you can use Pulumi to create the necessary infrastructure for real-time AI model serving with ECS:

1. **Define an ECS Cluster**: This cluster will be the compute environment where your containers will be deployed.

2. **Create an IAM role** for the ECS task execution: This role allows ECS to pull images and publish logs on behalf of your task.

3. **Define a Task Definition**: The task definition will outline the Docker container to be used, CPU and memory configurations, the Docker image to be run (which will contain your AI model), and other settings.

4. **Create a Service**: The ECS service keeps your container tasks running and can optionally ensure they are registered behind a load balancer.

5. **(Optional) Attach a Load Balancer**: If your AI model requires internet access or needs to be accessible from a web service, you will need to set up a load balancer.

Here's a Pulumi program in Python that sets up an ECS task definition for real-time AI model serving:

```python
import pulumi
import pulumi_aws as aws

# Create an ECS cluster
cluster = aws.ecs.Cluster("app-cluster")

# IAM role for ECS task execution. This role permits ECS to manage containers on your behalf.
task_exec_role = aws.iam.Role("task-exec-role", assume_role_policy={
    "Version": "2012-10-17",
    "Statement": [{
        "Action": "sts:AssumeRole",
        "Effect": "Allow",
        "Principal": {"Service": "ecs-tasks.amazonaws.com"},
    }],
})

# Attach the task execution role policy to the role
policy_attach = aws.iam.RolePolicyAttachment("task-exec-policy-attach",
    role=task_exec_role.name,
    policy_arn="arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy")

# Task definition for the container
task_definition = aws.ecs.TaskDefinition("app-task-def",
    family="app",
    cpu="256",
    memory="512",
    network_mode="awsvpc",
    # Note: You need to provide your own container image in the place of `your-account-id.dkr.ecr.region.amazonaws.com/your-repo-name:your-tag`
    # This image should contain your AI model code.
    requires_compatibilities=["FARGATE"],
    execution_role_arn=task_exec_role.arn,
    container_definitions=pulumi.Output.all(cluster.name).apply(lambda args: f"""
    [
        {{
            "name": "my_model_container",
            "image": "your-account-id.dkr.ecr.region.amazonaws.com/your-repo-name:your-tag",
            "portMappings": [
                {{
                    "containerPort": 80,
                    "hostPort": 80
                }}
            ],
            "essential": true,
            "cpu": 256,
            "memory": 512
        }}
    ]
    """))

# Create an ECS Service
service = aws.ecs.Service("app-svc",
    cluster=cluster.arn,
    task_definition=task_definition.arn,
    launch_type="FARGATE",
    desired_count=1,
    network_configuration={
        "assign_public_ip": True,
        "subnets": ["subnet-xxxxxxxxxxxxxx"]  # Replace with your actual subnet IDs
    }
)

# Export the DNS name of the load balancer to access the service
pulumi.export("service_name", service.name)
pulumi.export("cluster_name", cluster.name)
```

In this program:

- We've created an ECS cluster that will host our tasks.
- We've defined an IAM role that the ECS tasks will assume for permissions (like pulling container images and logging).
- We've defined an ECS task with the required CPU and memory resources. You'll need to swap in the proper Docker image URI with your AI model code.
- We've created an ECS service that will manage the tasks and ensure they are running. We've also noted that it should use a Fargate launch type. Amazon Fargate is a serverless compute engine for containers that works with Amazon ECS.
- Lastly, we export the service name and cluster name for further reference or use.

The subnet IDs used in the network configuration should be replaced with your own subnet IDs. Additionally, ensure that your model's Docker container image has all necessary permissions to access any AWS resources, like S3 buckets, that it might need.

Make sure to adjust the CPU and memory settings in the task definition and container definitions to meet the requirements of your AI model, and to use your actual Docker image in the container definitions.