Autoscaling EC2 GitLab Runners Spawned by Fargate
The purpose of the CloudFormation template is to create a Fargate Service that manages and autoscales EC2 instances to serve as a Gitlab CI executors. This allows for private GitLab Runners without managing, patching or maintaining servers.
Why Use EC2 executors?
At the time of writing, Fargate doesn't support the privileged task definition parameter for executors which ultimately means you can't use Docker-in-Docker to build/pull/push docker images in a Fargate executor. Anyone who is looking for a pure Fargate implementation should read this.
VpcId- Select a VPC that allows instances access to the Internet
SubnetID- Select subnets - Must be in the selected VPC!
GitLabURL- The Gitlab URL, change if self-hosted
GitLabRegistrationToken- The Gitlab runer registration token
RunnerRequestConcurrency- Specify the number of concurrent EC2 virtual machines to spawn (defaults to 12)
RunnerTagList- Optional parameter to specify the gitlab-runner tags (Example "docker,aws")
AdditionalRegisterParams- Any additional parameters you want to pass to
RunnerVersionThe GitLab runner version
InstanceType- The instance type of the runners
RootVolumeSize-The size of the root volume on the runners
CacheExpirationInDays- Select how long to store a jobs cache output in S3
CPU- Set the number of CPUs for the spawner (1 CPU = 1024)
Memory- Set the amount of RAM in KB for the spawner
DockerImage- The default docker image if not provided in a gitlab-ci.yml file
- IAM User - Used to connect to S3
- IAM Roles for ECS
- S3 Bucket for runner cache
- ECS Cluster, Service & Task Definition
- CloudWatch Logs Groups that streams to logs for the spawner