Fast Actions Runner for EC2, aka FARE

An EC2-based self-hosted runner for GitHub Actions.

FARE starts/stops pooled EC2 instances, for quick startup and warm caches.

Description

This self-hosted runner is cheaper than hosted GitHub Actions runners, and faster than alternatives.

Cheaper

At time of writing, GitHub's standard Linux runner is $0.48/hour for private repos, whereas EC2 m5.large is $0.10/hour. This discount scales to larger instance sizes as well.

Note that FARE workers incur EBS storage costs, which are $0.08/GB/month. (E.g. 10 workers with 64GB disks are $51/month for storage.)

Faster

Caches can be very helpful for build performance, but downloading and uploading distributed caches is slow. And GitHub Actions limits total cache size to 10GB/repository.

Instead, FARE maintains a pool of EC2 intances, and starts or stops them as necessary.

And instances may be used for multiple runs without restart, amortizing boot overhead and leveraging OS file caching.

Usage

1. Create controller.

Create a stack from https://redotech-fare-artifact.s3.us-east-1.amazonaws.com/<version>/fare-app.template.yaml

If other AWS accounts will be using the controller, grant lambda:InvokeFunction on the ProvisionerFunctionArn to those accounts.

2. Create a GitHub app.

From Step 1, read the SetupUrlFunctionArn output and invoke that Lambda function.

aws lambda invoke --function-name FunctionArn /dev/stdout | jq -rs '.[0].url'

Open the URL in your browser. You will be prompted to create a GitHub app. Accept.

3. Install the GitHub app.

Install the GitHub app to the necessary organizations or repositories.

4. Configure the provisioner(s).

You will need at least one label that will match job labels defined by GitHub actions. Organizations may create a runner group for to control access to the runners.

Provisioner

Create an EC2 launch template. Then use the Cloudformation template https://redotech-fare-artifact.s3.us-east-1.amazonaws.com/<version>/fare-provisioner.template.yaml.

Preset

Or use a preset that creates an EC2 launch template for you: https://redotech-fare-artifact.s3.us-east-1.amazonaws.com/<version>/fare-basic-provisioner.template.yaml.

You might also consider using a preset for creating the VPC, subnet, etc.: https://redotech-fare-artifact.s3.us-east-1.amazonaws.com/<version>/fare-basic-cluster.template.yaml.

Other

For details, see the docs.