https://github.com/infura/asg-instance-refresh

A minimal CLI tool to trigger an instance refresh on a EC2 autoscaling group
https://github.com/infura/asg-instance-refresh

Last synced: 27 days ago
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A minimal CLI tool to trigger an instance refresh on a EC2 autoscaling group

• Host: GitHub
• URL: https://github.com/infura/asg-instance-refresh
• Owner: INFURA
• License: mit
• Created: 2020-07-20T11:27:56.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2023-10-20T13:10:11.000Z (about 1 year ago)
• Last Synced: 2024-06-19T05:57:26.560Z (7 months ago)
• Language: Go
• Size: 65.4 KB
• Stars: 7
• Watchers: 8
• Forks: 5
• Open Issues: 1
• Metadata Files:
  • Readme: Readme.md
  • License: LICENSE

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README

        
# asg-instance-refresh

`asg-instance-refresh` is a minimal CLI tool to trigger an [instance refresh](https://docs.aws.amazon.com/autoscaling/ec2/userguide/asg-instance-refresh.html) on a EC2 autoscaling group.

## Installation

`GO111MODULE=off go get -u github.com/INFURA/asg-instance-refresh`

## Usage

`asg-instance-refresh `

## Flags

- `region` - The AWS region. Default to us-east-1.

- `strategy` - the selected refresh strategy. Default to "rolling".

- `warmup` - How long the new instances need to warm up. Default to the value for the health check grace period defined for the group.

- `minhealthy` - The minimum percentage capacity to retain during the recycling. Default to 100%.

- `wait` - Wait until the refresh is complete to return.

# Refresh strategies

`asg-instance-refresh` support the refresh strategies given by AWS. At the time of writing, only one strategy exist: `rolling`.

Because this `rolling` strategy is extremely slow, this tool support an additional strategy: `infura-refresh`. In short, this strategy works the following way:

- double the desired count

- wait for new healthy instances to appear

- enable scale-in protection on the new instances

- set back the desired count to normal

- wait for the old instances to get removed

- set the instance protection or not according to the ASG defined setting

## License

MIT