Hi there! What's the best way to get an ECS service name? It seems that a unique hash is assigned when I specify a name. For example, if my service name is "blah" it will actually be called "blah-3hd8d".

const fgService = new awsx.ecs.FargateService('blah', {
...
});

const autoScaleTarget = new aws.appautoscaling.Target(`appautoscaling-target-api-${stack}`, {
  resourceId: `service/${apiClusterName}/${apiServiceName}`, <----- ???
});

it should be an output on the resource you declared. Which also means the interpolation that you `???

'd won't work. you will need to do interpolation within an

.apply(...)`

so where exactly would I get the "output"? The TS types just say it returns a class, but I don't see anything "output" or name related

export declare class FargateService extends ecs.Service {
    readonly taskDefinition: FargateTaskDefinition;
    constructor(name: string, args: FargateServiceArgs, opts?: pulumi.ComponentResourceOptions);
}

so

FargateService

extends the

ecs.Service

resource from the core

pulumi-aws

provider. Which should have a

name

property. You can use that after declaring the service if you allowed pulumi to generate a suffix

haha yeah just figured that out...about to test it but now my stack is in a weird updating state 😕 so trying to fix that

@fresh-wire-95028 check the AWS console, the fargate service is probably pending 🙂

haha yeah fixed it by exporting the pulumi config then getting rid of the pending items and then importing. dunno if that was the right thing to do...but at least it doesn't give me that error anymore.

See here: https://www.pulumi.com/docs/intro/concepts/inputs-outputs/ Outputs function similarly to promises. That value is not known at execution time so you need to use the

.apply(...)

delegate in order to transform the value of the output to your desired result, a lot like a

Promise.then(...)

function. So your

resourceId

parameter could look something like this:

const fgService = new awsx.ecs.FargateService('blah', {
...
});

const autoScaleTarget = new aws.appautoscaling.Target(`appautoscaling-target-api-${stack}`, {
  resourceId: fgService.service.name.apply(serviceName => `service/${apiClusterName}/${serviceName}`),
});

If

apiClusterName

is also an output than there is another function you would use to get those 2 outputs into a single apply delegate.

this might also be helpful: https://www.leebriggs.co.uk/blog/2021/05/09/pulumi-apply.html

so I think I figured out the

apply

thing:

pulumi.all([fgService.service.name, cluster.cluster.name]).apply(([serviceName, clusterName]) => console.log(`service/${clusterName}/${serviceName}`));

outputs

service/api-cluster-development-564b394/api-svc-development-4a8c1f0

which looks correct. However...when I do:

const autoScaleTarget = new aws.appautoscaling.Target(`appautoscaling-target-api-${stack}`, {
  // max/min task instances
  maxCapacity: 10,
  minCapacity: 1,
  resourceId: pulumi.all([fgService.service.name, cluster.cluster.name]).apply(([serviceName, clusterName]) => `service/${clusterName}/${serviceName}`),
  scalableDimension: 'ecs:service:DesiredCount',
  serviceNamespace: 'ecs',
});

new aws.appautoscaling.Policy(`appautoscaling-policy-api-${stack}`, {
  policyType: 'TargetTrackingScaling',
  resourceId: autoScaleTarget.resourceId,
  scalableDimension: autoScaleTarget.scalableDimension,
  serviceNamespace: autoScaleTarget.serviceNamespace,
  targetTrackingScalingPolicyConfiguration: {
    predefinedMetricSpecification: {
      predefinedMetricType: 'ECSServiceAverageCPUUtilization',
    },
    // scale so that we use 20% CPU
    targetValue: 20,
  },
});

I get the following error:

aws:appautoscaling:Policy (appautoscaling-policy-api-development):
    error: 1 error occurred:
        * Failed to create scaling policy: ObjectNotFoundException: No scalable target registered for service namespace: ecs, resource ID: service/api-cluster-development-564b394/api-svc-development-4a8c1f0, scalable dimension: ecs:service:DesiredCount

which is weird, because the target didn't throw the error with the same

resourceId

What am I missing? Because I see the same

resourceId

that you said got logged and in the error

hmmm I might have had to specify the IAM role, even though it was optional. Here's my final working code, nicely modularized 😄

import * as pulumi from '@pulumi/pulumi';
import * as aws from '@pulumi/aws';
import * as awsx from '@pulumi/awsx';

interface IAutoScaleFargateServiceOpts {
  iamRole: aws.iam.Role,
  service: awsx.ecs.FargateService

  cluster: awsx.ecs.Cluster

  serviceName: string

  maxCount: number

  minCount: number

  CPUThreshold: number

  memoryThreshold: number
}
export default ({
  iamRole,
  service,
  cluster,
  serviceName,
  maxCount,
  minCount,
  CPUThreshold,
  memoryThreshold,
}: IAutoScaleFargateServiceOpts) => {
  const stack = pulumi.getStack();

  const autoScaleTarget = new aws.appautoscaling.Target(`appautoscaling-target-${serviceName}-${stack}`, {
    // max/min task instances
    maxCapacity: maxCount,
    minCapacity: minCount,
    roleArn: iamRole.arn,
    resourceId: pulumi.interpolate`service/${cluster.cluster.name}/${service.service.name}`,
    scalableDimension: 'ecs:service:DesiredCount',
    serviceNamespace: 'ecs',
  });

  const cpuScalingPolicy = new aws.appautoscaling.Policy(`appautoscaling-policy-cpu-api-${stack}`, {
    policyType: 'TargetTrackingScaling',
    resourceId: autoScaleTarget.resourceId,
    scalableDimension: autoScaleTarget.scalableDimension,
    serviceNamespace: autoScaleTarget.serviceNamespace,
    targetTrackingScalingPolicyConfiguration: {
      predefinedMetricSpecification: {
        predefinedMetricType: 'ECSServiceAverageCPUUtilization',
      },
      // scale so that we use max x% CPU
      targetValue: CPUThreshold,
    },
  });

  const memoryScalingPolicy = new aws.appautoscaling.Policy(`appautoscaling-policy-memory-api-${stack}`, {
    policyType: 'TargetTrackingScaling',
    resourceId: autoScaleTarget.resourceId,
    scalableDimension: autoScaleTarget.scalableDimension,
    serviceNamespace: autoScaleTarget.serviceNamespace,
    targetTrackingScalingPolicyConfiguration: {
      predefinedMetricSpecification: {
        predefinedMetricType: 'ECSServiceAverageMemoryUtilization',
      },
      // scale so that we use max x% Memory
      targetValue: memoryThreshold,
    },
  });

  return {
    cpuScalingPolicy,
    memoryScalingPolicy,
  };
};

awesome! glad you got it working. Btw I don't know if you're doing it for some other reason, but appending the stack name to the end of your resources is a little redundant. All of the resources in that stack are scoped to the stack just by way of the stack having its own state

hmm...but in the aws GUI I'd like to see the stack name. For example, in clusters I'd like to see: • api-cluster-development • api-cluster-staging

@fresh-wire-95028 if you want to modularize for reuse, you could consider making what you have a component resource

in that case you can use

NamePrefix

resource argument instead of relying on pulumi using the pulumi name. Then your resource name in AWS GUI can differ from your pulumi name

@billowy-army-68599 yeah that sounds like a great idea. I'm wondering if there are existing community component resources. like I can't imagine I'm the first one to need to scale fargate resources. but it took me quite a while to figure out how to do it. Or say, setting up a bucket with a custom domain. It's something that everyone needs to do, and requires a few steps (route 53, cert, dns validation, bucket policies, etc). Takes a good 150 lines of code with pulumi.

@fresh-wire-95028 we are working on something exactly like this, but it's not ready just yet for public consumption

Oooh excellent! Can't wait. Lmk if/how I can contribute or be part of a beta when it's available. I would say that's my #1 gripe with DevOps. All the tools out there are powerful but insanely verbose and require tons of background knowledge. I'd love to just have a bunch of prebuilt strategies that give me what I probably want, with the ability to customize as needed