https://github.com/miketheman/ecs-host-service-scale

Extending ECS Auto-scaling for under $2/month with Lambda
https://github.com/miketheman/ecs-host-service-scale

aws aws-lambda ecs ecs-service lambda

Last synced: 23 days ago
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Extending ECS Auto-scaling for under $2/month with Lambda

• Host: GitHub
• URL: https://github.com/miketheman/ecs-host-service-scale
• Owner: miketheman
• License: mit
• Created: 2017-01-07T21:19:34.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2018-03-16T09:46:28.000Z (over 6 years ago)
• Last Synced: 2024-10-12T09:10:46.393Z (about 1 month ago)
• Topics: aws, aws-lambda, ecs, ecs-service, lambda
• Language: Python
• Homepage: http://www.miketheman.net/2017/01/09/extending-ecs-auto-scaling-for-under-2month-with-lambda/
• Size: 13.7 KB
• Stars: 34
• Watchers: 6
• Forks: 30
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# ecs-host-service-scale

A Lambda function to ensure an ECS Service is set to the correct Desired Count for a One-Task-Per-Host placement value for any cluster that runs the Service.

## Requirements

- `boto3` (included in AWS Lambda functions, no need for packaged deployment)

- `ECS_SERVICE_ARN` environment variable

- IAM Role/Policy access setup

## Flow

![UML Sequence Flow](http://uml.mvnsearch.org/gist/00347bf8cfd22ac011f0e8f1bfa12359)

## Deployment

The function is meant to be deployed as a non-VPC Lambda function. It will probably work in a VPC environment, given an Internet Gateway and proper permissions, but it simply does not need access to any in-VPC resources, only AWS API calls.

- IAM Policy & IAM Role allowing: `ecs:Describe*` and `ecs:UpdateService`

- CloudWatch Event Rule for: `{"source": ["aws.ecs"], "detail-type": ["ECS Container Instance State Change"]}`

- Code from `lambda_function.py`

- The ECS Service ARN environment variable

## Testing

- Install all requirements via `pip install -r requirements.txt`

- Execute tests vis `pytest`

See [py.test docs](http://doc.pytest.org/) and [botocore Stubber](http://botocore.readthedocs.io/en/latest/reference/stubber.html) reference for more.

## Contributing

1. [Fork it](https://github.com/miketheman/ecs-host-service-scale/fork)

2. Create your feature branch (`git checkout -b my-new-feature`)

3. Test your changes with `pytest --cov` - the tests currently cover the code 100% - don't lower that number!

4. Commit your changes (`git commit -am 'Add some feature'`)

5. Push to the branch (`git push origin my-new-feature`)

6. Create a new Pull Request

# Author

[Mike Fiedler](https://github.com/miketheman) ([email protected])