EcsRunTask not deploy any task

[Fitmavincent]

Is the EcsRunTask designed to deploy a Ecs task, such as run a standalone task, task that runs once when it triggers?

// Run task
    const runTask = new EcsRunTask(this, 'RunOnceEC2Task', {
      integrationPattern: IntegrationPattern.RUN_JOB,
      cluster: cluster,
      taskDefinition: runOnceTaskDefinition,
      launchTarget: new EcsEc2LaunchTarget({
          placementStrategies: [
              PlacementStrategy.packedByCpu(),
          ],
        }
      ),
      comment: "A ecs task to run once when it deployed",
    });

No tasks being run in history. Checked CloudWatch logs as well. Nothing got run.

[pahud]

EcsRunTask is actually a task state. I believe you need define a state machine with definition to invoke it.

[Fitmavincent]

I've tried with the state machine as well. I defined the state machine and then use StepFunctionsStartExecution trying to invoke it. But it doesn't execute at all. Nothing is being run. I'm more interested to know whether the CDK has the capabilities to do that. If not, then I will go combine it with AWS CLI. Ideally, it will be better if I can integrate them all in one place in CDK in this case.

[pahud]

@Fitmavincent check out my full sample here

import {
  App, Stack, StackProps, Duration,
  aws_ecs as ecs,
  aws_ec2 as ec2,
  aws_stepfunctions as sfn,
  aws_stepfunctions_tasks as tasks,
} from 'aws-cdk-lib';
import { Construct } from 'constructs';


export class Demo extends Construct {
  constructor(scope: Construct, id: string) {
    super(scope, id);
    const vpc = ec2.Vpc.fromLookup(this, 'Vpc', {
      isDefault: true,
    });

    const cluster = new ecs.Cluster(this, 'Ec2Cluster', { vpc });

    const taskDefinition = new ecs.FargateTaskDefinition(this, 'TD', {
      cpu: 256,
      memoryLimitMiB: 512,
    });

    taskDefinition.addContainer('TheContainer', {
      image: ecs.ContainerImage.fromRegistry('public.ecr.aws/docker/library/busybox:unstable-uclibc'),
      memoryLimitMiB: 256,
      command: ['sh', '-c', 'ping google.com -c 2'],
      logging: new ecs.AwsLogDriver({
        streamPrefix: 'demo',
      }),
    });

    const runTask = new tasks.EcsRunTask(this, 'Run', {
      integrationPattern: sfn.IntegrationPattern.RUN_JOB,
      cluster,
      taskDefinition,
      assignPublicIp: true,
      launchTarget: new tasks.EcsFargateLaunchTarget(),
    });

    const startState = new sfn.Pass(this, 'StartState');
    const definition = startState
      .next(runTask);

    new sfn.StateMachine(this, 'StateMachine', {
      definition,
      timeout: Duration.minutes(5),
    });
  }

}

export class MyStack extends Stack {
  constructor(scope: Construct, id: string, props: StackProps = {}) {
    super(scope, id, props);

    // define resources here...
  }
}

// for development, use account/region from cdk cli
const devEnv = {
  account: process.env.CDK_DEFAULT_ACCOUNT,
  region: process.env.CDK_DEFAULT_REGION,
};

const app = new App();

const stack = new MyStack(app, 'gitpod-workspace-dev', { env: devEnv });
new Demo(stack, 'Demo');
// new MyStack(app, 'gitpod-workspace-prod', { env: prodEnv });

app.synth();

This CDK app creates a step function state machine that invokes a ecs task on Fargate with a container running "ping -c 3 google.com"

When I deploy it with cdk deploy I simply start the state machine workflow and I got the ECS log in cloudwatch logs like this:

Hope this sample helps.

[abury]

@pahud appreciate the detail you've put in here, but I can't get it the on Update to work to work with the sample you've provided. AwsCustomResource is different to CustomResource, and there is no properties value in AwsCustomResource

Running a once off task to do something like perform a migration I thought would be a very common use case, but I'm going deeper and deeper down a rabbit hole trying to do something I honestly thought would be quite simple. If someone is trying to deploy a rails or django app on Fargate, they need to perform a migration, typically using a once off task, before they can deploy. After days of reading I can't find any simple way of doing this in CDK, which is pretty surprising.

[pahud]

Hi @abury

AwsCustomReousrce is very handy when you just make a single SDK call. Check out this sample of mine that defines a custom resource to run an ecs task on fargate:
https://github.com/pahud/cdk-fargate-run-task/blob/7dcfcb927e7931afa992608a31e36c34df274bcf/src/run-task.ts#L137-L176

CustomResource on the other hand, is more flexible that you can pass properties to your lambda handler.

If you just need to trigger a SDK call without passing any props, consider to use AwsCustomReousrce, otherwise CustomResource with your custom lambda handler.

[modosc]

AwsCustomReousrce is very handy when you just make a single SDK call. Check out this sample of mine that defines a custom resource to run an ecs task on fargate: https://github.com/pahud/cdk-fargate-run-task/blob/7dcfcb927e7931afa992608a31e36c34df274bcf/src/run-task.ts#L137-L176

@pahud that link is dead, is there an updated version somewhere?

[pahud]

@modosc

Please check out the code snippets below:

// run it once by default with custom resource
    if (props.runAtOnce !== false) {
      const onEvent = {
        service: 'ECS',
        action: 'runTask',
        parameters: {
          cluster: cluster.clusterName,
          taskDefinition: task.taskDefinitionArn,
          capacityProviderStrategy: props.capacityProviderStrategy,
          launchType: props.launchType ?? (props.capacityProviderStrategy ? undefined : LaunchType.FARGATE),
          platformVersion: props.fargatePlatformVersion,
          // networkConfiguration is not required with the `EXTERNAL` launch type
          networkConfiguration: props.launchType === LaunchType.EXTERNAL ? undefined : {
            awsvpcConfiguration: {
              assignPublicIp: 'DISABLED',
              subnets: vpc.selectSubnets(props.vpcSubnets ?? {
                subnetType: ec2.SubnetType.PRIVATE_WITH_NAT,
              }).subnetIds,
              securityGroups: [this.securityGroup.securityGroupId],
            },
          },
        },
        physicalResourceId: cr.PhysicalResourceId.of(task.taskDefinitionArn),
      };
      const runTaskResource = new cr.AwsCustomResource(this, 'EcsRunTask', {
        onCreate: onEvent,
        onUpdate: props.runOnResourceUpdate ? onEvent : undefined,
        policy: cr.AwsCustomResourcePolicy.fromSdkCalls({ resources: [task.taskDefinitionArn] }),
        logRetention: props.logRetention ?? logs.RetentionDays.ONE_WEEK,
        resourceType: 'Custom::RunTask',
      });
      this.runOnceResource = runTaskResource;

      // allow lambda from custom resource to iam:PassRole on the ecs task role and execution role
      task.taskRole.grantPassRole(runTaskResource.grantPrincipal);
      if (task.executionRole) task.executionRole.grantPassRole(runTaskResource.grantPrincipal);
    }

  }
}

We probably need to publish the full sample in aws-cdk-examples but this is what I can provide for now.

[lucasmaia1202]

This helped a lot!

[pahud]

Hi @Fitmavincent would you please click the "Mark as answer" button to help us better track the activities? Thanks.

[Fitmavincent]

Done. Thx @pahud .

[github-actions[bot]]

Hello! Reopening this discussion to make it searchable.

[kisharma24]

Does runtask make sure that or wait until container completes its work/command in this case?

[ricky-lim]

Hi @pahud,

I am curious about your repo: https://github.com/pahud/cdk-fargate-run-task/, since it's no longer found.
Is there an example to create AWS custom resource backed by ECS fargate task ?

Thanks in advance