Application Auto Scaling

Overview

CloudMock emulates AWS Application Auto Scaling, supporting scalable target registration, TargetTracking and StepScaling policies, scheduled actions, and resource tagging across multiple service namespaces (ECS, DynamoDB, RDS, Lambda, SageMaker, and more).

Supported Operations

Operation	Status	Notes
RegisterScalableTarget	Supported	Register or update; idempotent
DescribeScalableTargets	Supported	Filter by namespace, resource IDs, dimension
DeregisterScalableTarget	Supported	Removes target
PutScalingPolicy	Supported	TargetTrackingScaling and StepScaling types
DescribeScalingPolicies	Supported	Filter by namespace, resource, dimension
DeleteScalingPolicy	Supported
PutScheduledAction	Supported	Upsert; start/end times supported
DescribeScheduledActions	Supported	Filter by namespace and resource
DeleteScheduledAction	Supported
TagResource	Supported	Tags policies and scheduled actions by ARN
UntagResource	Supported
ListTagsForResource	Supported

Supported Service Namespaces

ecs, dynamodb, ec2, rds, sagemaker, custom-resource, comprehend, lambda, cassandra, kafka, elasticache, neptune

Quick Start

Node.js

import {
  ApplicationAutoScalingClient,
  RegisterScalableTargetCommand,
  PutScalingPolicyCommand,
  PutScheduledActionCommand,
} from '@aws-sdk/client-application-auto-scaling';

const client = new ApplicationAutoScalingClient({
  endpoint: 'http://localhost:4566',
  region: 'us-east-1',
  credentials: { accessKeyId: 'test', secretAccessKey: 'test' },
});

await client.send(new RegisterScalableTargetCommand({
  ServiceNamespace: 'ecs',
  ResourceId: 'service/my-cluster/my-service',
  ScalableDimension: 'ecs:service:DesiredCount',
  MinCapacity: 1,
  MaxCapacity: 10,
}));

await client.send(new PutScalingPolicyCommand({
  PolicyName: 'cpu-tracking',
  ServiceNamespace: 'ecs',
  ResourceId: 'service/my-cluster/my-service',
  ScalableDimension: 'ecs:service:DesiredCount',
  PolicyType: 'TargetTrackingScaling',
  TargetTrackingScalingPolicyConfiguration: { TargetValue: 70.0 },
}));

Python

import boto3

client = boto3.client('application-autoscaling',
    endpoint_url='http://localhost:4566',
    region_name='us-east-1',
    aws_access_key_id='test',
    aws_secret_access_key='test')

client.register_scalable_target(
    ServiceNamespace='dynamodb',
    ResourceId='table/my-table',
    ScalableDimension='dynamodb:table:ReadCapacityUnits',
    MinCapacity=5,
    MaxCapacity=1000)

client.put_scaling_policy(
    PolicyName='read-capacity-tracking',
    ServiceNamespace='dynamodb',
    ResourceId='table/my-table',
    ScalableDimension='dynamodb:table:ReadCapacityUnits',
    PolicyType='TargetTrackingScaling',
    TargetTrackingScalingPolicyConfiguration={'TargetValue': 70.0})

Configuration

cloudmock.yml

services:
  applicationautoscaling:
    enabled: true

Known Differences from AWS

• Scaling policies are stored but do not trigger actual scaling actions automatically
• Scheduled actions are stored but do not execute on their cron schedule
• No integration with CloudWatch metrics for target tracking