cluster-cleanup

Library to fill the gap between the SDK and the CLI/Console for deleting an ECS cluster. Also comes with a CLI as of version 3.0.0!

What does this do?

The CLI and the ECS Console go through about 9 steps to clean up an ECS cluster but the SDK doesn't have any provisions to do this. The steps are listed below and this library notifies the user as these steps are completed.

1. Find CloudFormation stack
2. Find all services
3. Scale all services down to 0
4. Find all running tasks
5. Stop all running tasks
6. Find all container instances
7. Deregister all container instances
8. Delete all services
9. Delete CloudFormation stack
10. Poll CloudFormation until stack is deleted or timeout
11. Attempt deleting the cluster

Usage

CLI

Run npm install --global cluster-cleanup to install the CLI. Once installed, run cluster-cleanup --help to learn about all the options. This CLI interfaces with AWS so credentials are required. The CLI can use credentials already configured from AWS CLI, and there are options to pass in an assume role ARN (and an external ID) or to use a profile.

You can also just pass in the credentials themselves. It is done this way to support multiple entrypoints for credentials, somewhat modeled after the AWS CLI/SDK behavior. There is also a --no-color option to disable color output, in case the logs need to be captured and parsed.

Library usage

Run npm install cluster-cleanup to pull down the package. Require it in your code, and create an instance of the ClusterCleanup class which can be passed the same config object as the AWS SDK. You can then use it to delete clusters completely including the resources that come with ECS clusters. Sample code below.

const { ClusterCleanup, ClusterCleanupEvents } = require('cluster-cleanup');

const clusterCleanup = new ClusterCleanup();
const events = clusterCleanup.eventEmitter;

async () => {
  const deletedResources = clusterCleanup.deleteClusterAndResources('default');

  events.on(ClusterCleanupEvents.error, (e) => console.error(e));
  events.on(ClusterCleanupEvents.done, () => console.log('Done'));
};

The ClusterCleanup constructor takes the standard AWS SDK for Node.js options object. The constructor, optionally, can also take initialized clients for ECS and CloudFormation if you don't want ClusterCleanup to create new clients.

The deleteClusterAndResources function can be provided a stack name (2nd argument) as well as a verbose option as a number (3rd argument). Additionally, it take an object with the following properties as the last argument,

• a property called waiterTimeoutMs which is the timeout in milliseconds for the AWS SDK waiter to wait for the CloudFormation stack to be deleted, defaults to 10 minutes
• a property called waiterPollMinDelayMs which is the minimum delay in milliseconds between each run of cloudformation::describeStacks with the stack being deleted, defaults to 30 seconds
• a property called stackEventsPollIntervalMs which is the interval in milliseconds between each run of cloudformation::describeStackEvents for the stack being deleted, defaults to 30 seconds

We call cloudformation::describeStackEvents so that we can get information on the cleanup of the resources specified by the stack. We set up a waiter that uses cloudformation::describeStacks to wait for the stack being deleted.

All of the arguments besides the cluster name are optional.

Events

The events instance returned from the ClusterCleanup.events getter call inherits from the Node.js EventEmitter and adds override type signatures to the on method to increase visibility into what events are emitted and what data goes along with each event. Calling on also returns a function that can be called to remove the listener. The events and the expected data passed to the listener are listed below.

Event	Data and Type
start	clusterName: string
stackFound	stack: CloudFormation.Stack
servicesFound	serviceArns: string[]
servicesScaledDown	services: ECS.Service[]
tasksFound	taskArns: string[]
tasksStopped	tasks: ECS.Task[]
instancesFound	instanceArns: string[]
instancesDeregistered	instances: ECS.ContainerInstance[]
stackDeletionStarted	stackId: string
stackDeletionDone	stackId: string
resourceDeleted	event: CloudFormation.StackEvent
clusterDeleted	cluster: ECS.Cluster
done	clusterName: string
error	error: Error
doneWithError	error: Error

For example, to listen for when the CloudFormation stack is deleted,

const removeListener = events.on(
  ClusterCleanupEvents.stackDeletionDone,
  (stackId) => {
    console.log(`Stack ${stackId} deleted!`);
  }
);

// other code

removeListener();

All of this information is also surfaced via typings that are included in this library.

ClI Support

This package also vends a decorator that listens to all the events and logs out everything (with some color using chalk) to the console. This is meant to make creating an executable file that runs this script a bit better and remove duplication of code.

This package also includes an executable that uses the CLI suppport functions to allow users to configure and run the cluster cleanup script. Run ./bin/cluster-cleanup --help to see all the configuration options.

Issue and PR templates derived from smhxx/atom-ts-transpiler.