feat(aws-ecs): add ECS/Fargate QueueWorkerService constructs

design/aws-ecs-autoscaling-queue-worker.md

@@ -0,0 +1,232 @@
+# AWS ECS - L3 Construct for Autoscaling ECS/Fargate Service that Processes Items in a SQS Queue
+
+To address issue [#2396](https://github.com/awslabs/aws-cdk/issues/2396), the AWS ECS CDK construct library should provide a way for customers to create a queue worker service (an AWS ECS/Fargate service that processes items from an sqs queue). This would mean adding new ECS CDK constructs `Ec2QueueWorkerService` and `FargateQueryWorkerService`, that would take in the necessary properties required to create a task definition, an SQS queue as well as an ECS/Fargate service and enable autoscaling for the service based on cpu usage and the SQS queue's approximateNumberOfMessagesVisible metric. 
+
+## General approach
+
+The new `ecs.QueueWorkerServiceBase`, `ecs.Ec2QueueWorkerService` and `ecs.FargateQueueWorkerService` classes will create L3 constructs for:
+
+* Ec2QueueWorkerService
+* FargateQueueWorkerService
+
+A `QueueWorkerService` will create a task definition with the specified container (on both EC2 and Fargate). An AWS SQS `Queue` will be created and autoscaling of the ECS Service will be dependent on both CPU as well as the SQS queue's `ApproximateNumberOfMessagesVisible` metric. 
+
+The `QueueWorkerService` constructs (for EC2 and Fargate) will use the following existing constructs:
+
+* Ec2TaskDefinition/FargateTaskDefinition - To create a Task Definition for the container to start
+* SQSQueue - The queue that the worker is processing from
+* Ec2Service/FargateService - The Service running the container
+
+## Code changes
+
+Given the above, we should make the following changes to support queue workers on ECS (for both EC2 and Fargate):
+1. Create `QueueWorkerServiceBaseProps` interface and `QueueWorkerServiceBase` construct
+2. Create `Ec2QueueWorkerServiceProps` interface and `Ec2QueueWorkerService` construct
+3. Create `FargateQueueWorkerServiceProps` interface and `FargateQueueWorkerService` construct
+
+### Part 1: Create `QueueWorkerServiceBaseProps` interface and `QueueWorkerServiceBase` construct 
+
+The `QueueWorkerServiceBaseProps` interface will contain common properties used to construct both the Ec2QueueWorkerService and the FargateQueueWorkerService:
+
+```ts
+/**
+ * Properties to define a Query Worker service
+ */
+export interface QueueWorkerServiceBaseProps {
+ /**
+ * Cluster where service will be deployed
+ */
+ readonly cluster: ICluster;
+
+ /**
+ * The image to start.
+ */
+ readonly image: ContainerImage;
+
+ /**
+ * The CMD value to pass to the container as a string array.
+ *
+ * @default none
+ */
+ readonly command?: string[];
+
+ /**
+ * Number of desired copies of running tasks
+ *
+ * @default 1
+ */
+ readonly desiredTaskCount?: number;
+
+ /**
+ * Flag to indicate whether to enable logging
+ *
+ * @default true
+ */
+ readonly enableLogging?: boolean;
+
+ /**
+ * The environment variables to pass to the container.
+ *
+ * @default 'QUEUE_NAME: queue.queueName'
+ */
+ readonly environment?: { [key: string]: string };
+
+ /**
+ * A queue for which to process items from.
+ *
+ * If specified and this is a FIFO queue, the queue name must end in the string '.fifo'.
+ * @see https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_CreateQueue.html
+ *
+ * @default 'SQSQueue with CloudFormation-generated name'
+ */
+ readonly queue?: IQueue;
+
+ /**
+ * Maximum capacity to scale to.
+ *
+ * @default (desiredTaskCount * 2)
+ */
+ readonly maxScalingCapacity?: number
+
+ /**
+ * The intervals for scaling based on the SQS queue's ApproximateNumberOfMessagesVisible metric.
+ *
+ * Maps a range of metric values to a particular scaling behavior.
+ * https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-scaling-simple-step.html
+ * 
+ * @default [{ upper: 0, change: -1 },{ lower: 100, change: +1 },{ lower: 500, change: +5 }]
+ */
+ readonly scalingSteps: autoScaling.ScalingInterval[];
+}
+```
+
+### Part 2: Create `Ec2QueueWorkerServiceProps` interface and `Ec2QueueWorkerService` construct 
+
+The `Ec2QueueWorkerServiceProps` interface will contain properties to construct the Ec2TaskDefinition, SQSQueue and Ec2Service:
+
+```ts
+/**
+ * Properties to define an ECS service
+ */
+export interface Ec2QueueWorkerServiceProps {
+ /**
+ * The minimum number of CPU units to reserve for the container.
+ *
+ * @default none
+ */
+ readonly cpu?: number;
+
+ /**
+ * The hard limit (in MiB) of memory to present to the container.
+ *
+ * If your container attempts to exceed the allocated memory, the container
+ * is terminated.
+ *
+ * At least one of memoryLimitMiB and memoryReservationMiB is required for non-Fargate services.
+ */
+ readonly memoryLimitMiB?: number;
+
+ /**
+ * The soft limit (in MiB) of memory to reserve for the container.
+ *
+ * When system memory is under contention, Docker attempts to keep the
+ * container memory within the limit. If the container requires more memory,
+ * it can consume up to the value specified by the Memory property or all of
+ * the available memory on the container instance—whichever comes first.
+ *
+ * At least one of memoryLimitMiB and memoryReservationMiB is required for non-Fargate services.
+ */
+ readonly memoryReservationMiB?: number;
+}
+```
+
+An example use case:
+```ts
+// Create the vpc and cluster used by the Queue Worker task
+const vpc = new ec2.VpcNetwork(stack, 'Vpc', { maxAZs: 1 });
+const cluster = new ecs.Cluster(stack, 'EcsCluster', { vpc });
+cluster.addCapacity('DefaultAutoScalingGroup', {
+ instanceType: new ec2.InstanceType('t2.micro')
+});
+const queue = new sqs.Queue(stack, 'WorkerQueue', { 
+ QueueName: 'EcsWorkerQueue'
+});
+
+// Create the Queue Worker task
+new Ec2QueueWorkerService(stack, 'EcsQueueWorkerService', {
+ cluster,
+ image: ecs.ContainerImage.fromRegistry('amazon/amazon-ecs-sample'),
+ desiredTaskCount: 2,
+ maxScalingCapacity: 5,
+ memoryReservationMiB: 512,
+ cpu: 256,
+ queue
+});
+```
+
+### Part 3: Create `FargateQueueWorkerServiceProps` interface and `FargateQueueWorkerService` construct 
+
+The `FargateQueueWorkerServiceProps` interface will contain properties to construct the FargateTaskDefinition, SQSQueue and FargateService:
+
+```ts
+/**
+ * Properties to define an Fargate service
+ */
+export interface FargateQueueWorkerServiceProps {
+ /**
+ * The number of cpu units used by the task.
+ * Valid values, which determines your range of valid values for the memory parameter:
+ * 256 (.25 vCPU) - Available memory values: 0.5GB, 1GB, 2GB
+ * 512 (.5 vCPU) - Available memory values: 1GB, 2GB, 3GB, 4GB
+ * 1024 (1 vCPU) - Available memory values: 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB
+ * 2048 (2 vCPU) - Available memory values: Between 4GB and 16GB in 1GB increments
+ * 4096 (4 vCPU) - Available memory values: Between 8GB and 30GB in 1GB increments
+ *
+ * This default is set in the underlying FargateTaskDefinition construct.
+ *
+ * @default 256
+ */
+ readonly cpu?: string;
+
+ /**
+ * The amount (in MiB) of memory used by the task.
+ *
+ * This field is required and you must use one of the following values, which determines your range of valid values
+ * for the cpu parameter:
+ *
+ * 0.5GB, 1GB, 2GB - Available cpu values: 256 (.25 vCPU)
+ *
+ * 1GB, 2GB, 3GB, 4GB - Available cpu values: 512 (.5 vCPU)
+ *
+ * 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB - Available cpu values: 1024 (1 vCPU)
+ *
+ * Between 4GB and 16GB in 1GB increments - Available cpu values: 2048 (2 vCPU)
+ *
+ * Between 8GB and 30GB in 1GB increments - Available cpu values: 4096 (4 vCPU)
+ *
+ * This default is set in the underlying FargateTaskDefinition construct.
+ *
+ * @default 512
+ */
+ readonly memoryMiB?: string;
+}
+```
+
+An example use case:
+```ts
+// Create the vpc and cluster used by the Queue Worker task
+const vpc = new ec2.VpcNetwork(stack, 'Vpc', { maxAZs: 2 });
+const cluster = new ecs.Cluster(stack, 'FargateCluster', { vpc });
+const queue = new sqs.Queue(stack, 'WorkerQueue', { 
+ QueueName: 'FargateWorkerQueue'
+});
+
+// Create the Queue Worker task
+new FargateQueueWorkerService(stack, 'FargateQueueWorkerService', {
+ cluster,
+ image: ecs.ContainerImage.fromRegistry('amazon/amazon-ecs-sample'),
+ desiredTaskCount: 2,
+ maxScalingCapacity: 5,
+ queue
+});
+```

packages/@aws-cdk/aws-ecs/lib/ecs-queue-worker-service.ts

@@ -0,0 +1,68 @@
+import cdk = require('@aws-cdk/cdk');
+import { Ec2Service } from './ec2/ec2-service';
+import { Ec2TaskDefinition } from './ec2/ec2-task-definition';
+import { QueueWorkerServiceBase, QueueWorkerServiceBaseProps } from './queue-worker-service-base';
+
+/**
+ * Properties to define an Ec2 query worker service
+ */
+export interface Ec2QueueWorkerServiceProps extends QueueWorkerServiceBaseProps {
+ /**
+ * The minimum number of CPU units to reserve for the container.
+ *
+ * @default none
+ */
+ readonly cpu?: number;
+
+ /**
+ * The hard limit (in MiB) of memory to present to the container.
+ *
+ * If your container attempts to exceed the allocated memory, the container
+ * is terminated.
+ *
+ * At least one of memoryLimitMiB and memoryReservationMiB is required for non-Fargate services.
+ */
+ readonly memoryLimitMiB?: number;
+
+ /**
+ * The soft limit (in MiB) of memory to reserve for the container.
+ *
+ * When system memory is under contention, Docker attempts to keep the
+ * container memory within the limit. If the container requires more memory,
+ * it can consume up to the value specified by the Memory property or all of
+ * the available memory on the container instance—whichever comes first.
+ *
+ * At least one of memoryLimitMiB and memoryReservationMiB is required for non-Fargate services.
+ */
+ readonly memoryReservationMiB?: number;
+}
+
+/**
+ * Class to create an Ec2 query worker service
+ */
+export class Ec2QueueWorkerService extends QueueWorkerServiceBase {
+ constructor(scope: cdk.Construct, id: string, props: Ec2QueueWorkerServiceProps) {
+ super(scope, id, props);
+
+ // Create a Task Definition for the container to start
+ const taskDefinition = new Ec2TaskDefinition(this, 'QueueWorkerTaskDef');
+ taskDefinition.addContainer('QueueWorkerContainer', {
+ image: props.image,
+ memoryLimitMiB: props.memoryLimitMiB,
+ memoryReservationMiB: props.memoryReservationMiB,
+ cpu: props.cpu,
+ command: props.command,
+ environment: this.environment,
+ logging: this.logDriver
+ });
+
+ // Create an ECS service with the previously defined Task Definition and configure
+ // autoscaling based on cpu utilization and number of messages visible in the SQS queue.
+ const ecsService = new Ec2Service(this, 'QueueWorkerService', {
+ cluster: props.cluster,
+ desiredCount: this.desiredCount,
+ taskDefinition
+ });
+ this.configureAutoscalingForService(ecsService);
+ }
+}

packages/@aws-cdk/aws-ecs/lib/fargate-queue-worker-service.ts

@@ -0,0 +1,76 @@
+import cdk = require('@aws-cdk/cdk');
+import { FargateService } from './fargate/fargate-service';
+import { FargateTaskDefinition } from './fargate/fargate-task-definition';
+import { QueueWorkerServiceBase, QueueWorkerServiceBaseProps } from './queue-worker-service-base';
+
+/**
+ * Properties to define a Fargate queue worker service
+ */
+export interface FargateQueueWorkerServiceProps extends QueueWorkerServiceBaseProps {
+ /**
+ * The number of cpu units used by the task.
+ * Valid values, which determines your range of valid values for the memory parameter:
+ * 256 (.25 vCPU) - Available memory values: 0.5GB, 1GB, 2GB
+ * 512 (.5 vCPU) - Available memory values: 1GB, 2GB, 3GB, 4GB
+ * 1024 (1 vCPU) - Available memory values: 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB
+ * 2048 (2 vCPU) - Available memory values: Between 4GB and 16GB in 1GB increments
+ * 4096 (4 vCPU) - Available memory values: Between 8GB and 30GB in 1GB increments
+ *
+ * This default is set in the underlying FargateTaskDefinition construct.
+ *
+ * @default 256
+ */
+ readonly cpu?: string;
+
+ /**
+ * The amount (in MiB) of memory used by the task.
+ *
+ * This field is required and you must use one of the following values, which determines your range of valid values
+ * for the cpu parameter:
+ *
+ * 0.5GB, 1GB, 2GB - Available cpu values: 256 (.25 vCPU)
+ *
+ * 1GB, 2GB, 3GB, 4GB - Available cpu values: 512 (.5 vCPU)
+ *
+ * 2GB, 3GB, 4GB, 5GB, 6GB, 7GB, 8GB - Available cpu values: 1024 (1 vCPU)
+ *
+ * Between 4GB and 16GB in 1GB increments - Available cpu values: 2048 (2 vCPU)
+ *
+ * Between 8GB and 30GB in 1GB increments - Available cpu values: 4096 (4 vCPU)
+ *
+ * This default is set in the underlying FargateTaskDefinition construct.
+ *
+ * @default 512
+ */
+ readonly memoryMiB?: string;
+}
+
+/**
+ * Class to create a Fargate query worker service
+ */
+export class FargateQueueWorkerService extends QueueWorkerServiceBase {
+ constructor(scope: cdk.Construct, id: string, props: FargateQueueWorkerServiceProps) {
+ super(scope, id, props);
+
+ // Create a Task Definition for the container to start
+ const taskDefinition = new FargateTaskDefinition(this, 'QueueWorkerTaskDef', {
+ memoryMiB: props.memoryMiB !== undefined ? props.memoryMiB : '512',
+ cpu: props.cpu !== undefined ? props.cpu : '256',
+ });
+ taskDefinition.addContainer('QueueWorkerContainer', {
+ image: props.image,
+ command: props.command,
+ environment: this.environment,
+ logging: this.logDriver
+ });
+
+ // Create a Fargate service with the previously defined Task Definition and configure
+ // autoscaling based on cpu utilization and number of messages visible in the SQS queue.
+ const fargateService = new FargateService(this, 'FargateQueueWorkerService', {
+ cluster: props.cluster,
+ desiredCount: this.desiredCount,
+ taskDefinition
+ });
+ this.configureAutoscalingForService(fargateService);
+ }
+}

packages/@aws-cdk/aws-ecs/lib/index.ts

@@ -20,6 +20,10 @@ export * from './load-balanced-fargate-service';
 export * from './load-balanced-ecs-service';
 export * from './load-balanced-fargate-service-applet';
 
+export * from './queue-worker-service-base';
+export * from './ecs-queue-worker-service';
+export * from './fargate-queue-worker-service';
+
 export * from './images/asset-image';
 export * from './images/repository';
 export * from './images/ecr';