feat: warm pool — stop/start idle runners for fast restart

README.md

@@ -167,7 +167,7 @@ Join our discord community via [this invite link](https://discord.gg/bxgXW8jJGh)
 | <a name="input_logging_kms_key_id"></a> [logging\_kms\_key\_id](#input\_logging\_kms\_key\_id) | Specifies the kms key id to encrypt the logs with. | `string` | `null` | no |
 | <a name="input_logging_retention_in_days"></a> [logging\_retention\_in\_days](#input\_logging\_retention\_in\_days) | Specifies the number of days you want to retain log events for the lambda log group. Possible values are: 0, 1, 3, 5, 7, 14, 30, 60, 90, 120, 150, 180, 365, 400, 545, 731, 1827, and 3653. | `number` | `180` | no |
 | <a name="input_matcher_config_parameter_store_tier"></a> [matcher\_config\_parameter\_store\_tier](#input\_matcher\_config\_parameter\_store\_tier) | The tier of the parameter store for the matcher configuration. Valid values are `Standard`, and `Advanced`. | `string` | `"Standard"` | no |
-| <a name="input_metrics"></a> [metrics](#input\_metrics) | Configuration for metrics created by the module, by default disabled to avoid additional costs. When metrics are enable all metrics are created unless explicit configured otherwise. | <pre>object({<br/>    enable    = optional(bool, false)<br/>    namespace = optional(string, "GitHub Runners")<br/>    metric = optional(object({<br/>      enable_github_app_rate_limit    = optional(bool, true)<br/>      enable_job_retry                = optional(bool, true)<br/>      enable_spot_termination_warning = optional(bool, true)<br/>    }), {})<br/>  })</pre> | `{}` | no |
+| <a name="input_metrics"></a> [metrics](#input\_metrics) | Configuration for metrics created by the module, by default disabled to avoid additional costs. When metrics are enable all metrics are created unless explicit configured otherwise. | <pre>object({<br/>    enable    = optional(bool, false)<br/>    namespace = optional(string, "GitHub Runners")<br/>    metric = optional(object({<br/>      enable_github_app_rate_limit    = optional(bool, true)<br/>      enable_job_retry                = optional(bool, true)<br/>      enable_spot_termination_warning = optional(bool, true)<br/>      enable_warm_pool                = optional(bool, true)<br/>    }), {})<br/>  })</pre> | `{}` | no |
 | <a name="input_minimum_running_time_in_minutes"></a> [minimum\_running\_time\_in\_minutes](#input\_minimum\_running\_time\_in\_minutes) | The time an ec2 action runner should be running at minimum before terminated, if not busy. | `number` | `null` | no |
 | <a name="input_parameter_store_tags"></a> [parameter\_store\_tags](#input\_parameter\_store\_tags) | Map of tags that will be added to all the SSM Parameter Store parameters created by the Lambda function. | `map(string)` | `{}` | no |
 | <a name="input_pool_config"></a> [pool\_config](#input\_pool\_config) | The configuration for updating the pool. The `pool_size` to adjust to by the events triggered by the `schedule_expression`. For example you can configure a cron expression for weekdays to adjust the pool to 10 and another expression for the weekend to adjust the pool to 1. Use `schedule_expression_timezone` to override the schedule time zone (defaults to UTC). | <pre>list(object({<br/>    schedule_expression          = string<br/>    schedule_expression_timezone = optional(string)<br/>    size                         = number<br/>  }))</pre> | `[]` | no |
@@ -176,6 +176,7 @@ Join our discord community via [this invite link](https://discord.gg/bxgXW8jJGh)
 | <a name="input_pool_lambda_reserved_concurrent_executions"></a> [pool\_lambda\_reserved\_concurrent\_executions](#input\_pool\_lambda\_reserved\_concurrent\_executions) | Amount of reserved concurrent executions for the scale-up lambda function. A value of 0 disables lambda from being triggered and -1 removes any concurrency limitations. | `number` | `1` | no |
 | <a name="input_pool_lambda_timeout"></a> [pool\_lambda\_timeout](#input\_pool\_lambda\_timeout) | Time out for the pool lambda in seconds. | `number` | `60` | no |
 | <a name="input_pool_runner_owner"></a> [pool\_runner\_owner](#input\_pool\_runner\_owner) | The pool will deploy runners to the GitHub org ID, set this value to the org to which you want the runners deployed. Repo level is not supported. | `string` | `null` | no |
+| <a name="input_pool_strategy"></a> [pool\_strategy](#input\_pool\_strategy) | Strategy for maintaining idle runners: `hot` (default, traditional) or `warm` (stop instead of terminate). Requires `warm_pool_config.enabled = true` when set to `warm`. | `string` | `"hot"` | no |
 | <a name="input_prefix"></a> [prefix](#input\_prefix) | The prefix used for naming resources | `string` | `"github-actions"` | no |
 | <a name="input_queue_encryption"></a> [queue\_encryption](#input\_queue\_encryption) | Configure how data on queues managed by the modules is encrypted at REST. Options are encrypted via SSE, non encrypted and via KMS. By default encrypted via SSE is enabled. See for more details the Terraform `aws_sqs_queue` resource https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/sqs_queue. | <pre>object({<br/>    kms_data_key_reuse_period_seconds = number<br/>    kms_master_key_id                 = string<br/>    sqs_managed_sse_enabled           = bool<br/>  })</pre> | <pre>{<br/>  "kms_data_key_reuse_period_seconds": null,<br/>  "kms_master_key_id": null,<br/>  "sqs_managed_sse_enabled": true<br/>}</pre> | no |
 | <a name="input_queue_selection_strategy"></a> [queue\_selection\_strategy](#input\_queue\_selection\_strategy) | Strategy used to pick a queue when multiple runner configurations match a job equally well. `first` keeps the historical deterministic behaviour (the first matching queue by priority). `random` spreads jobs across the matching queues to avoid concentrating load on a single one. `all` scales up one runner per matching queue and lets the first to become available take the job (favouring speed over cost; this multiplies instance launches and runner registrations per job). | `string` | `"first"` | no |
@@ -239,6 +240,7 @@ Join our discord community via [this invite link](https://discord.gg/bxgXW8jJGh)
 | <a name="input_userdata_pre_install"></a> [userdata\_pre\_install](#input\_userdata\_pre\_install) | Script to be ran before the GitHub Actions runner is installed on the EC2 instances | `string` | `""` | no |
 | <a name="input_userdata_template"></a> [userdata\_template](#input\_userdata\_template) | Alternative user-data template file path, replacing the default template. By providing your own user\_data you have to take care of installing all required software, including the action runner. Variables userdata\_pre/post\_install are ignored. | `string` | `null` | no |
 | <a name="input_vpc_id"></a> [vpc\_id](#input\_vpc\_id) | The VPC for security groups of the action runners. | `string` | n/a | yes |
+| <a name="input_warm_pool_config"></a> [warm\_pool\_config](#input\_warm\_pool\_config) | Configuration for the warm pool feature. When enabled, idle runners are stopped instead of terminated, allowing 10-30s restart times instead of 2-5 minute cold starts. | <pre>object({<br/>    enabled                       = optional(bool, false)<br/>    max_warm_instances            = optional(number, 3)<br/>    max_warm_age_hours            = optional(number, 168)<br/>    warm_pool_ready_delay_seconds = optional(number, 30)<br/>  })</pre> | `{}` | no |
 | <a name="input_webhook_lambda_apigateway_access_log_settings"></a> [webhook\_lambda\_apigateway\_access\_log\_settings](#input\_webhook\_lambda\_apigateway\_access\_log\_settings) | Access log settings for webhook API gateway. | <pre>object({<br/>    destination_arn = string<br/>    format          = string<br/>  })</pre> | `null` | no |
 | <a name="input_webhook_lambda_memory_size"></a> [webhook\_lambda\_memory\_size](#input\_webhook\_lambda\_memory\_size) | Memory size limit in MB for webhook lambda in. | `number` | `256` | no |
 | <a name="input_webhook_lambda_s3_key"></a> [webhook\_lambda\_s3\_key](#input\_webhook\_lambda\_s3\_key) | S3 key for webhook lambda function. Required if using S3 bucket to specify lambdas. | `string` | `null` | no |