* Add POC of GitHub Webhook Delivery Forwarder
* multi-forwarder and ctrl-c existing and fix for non-woring http post
* Rename source files
* Extract signal handling into a dedicated source file
* Faster ctrl-c handling
* Enable automatic creation of repo hook on startup
* Add support for forwarding org hook deliveries
* Set hook secret on hook creation via envvar (HOOK_SECRET)
* Fix org hook support
* Fix HOOK_SECRET for consistency
* Refactor to prepare for custom log position provider
* Refactor to extract inmemory log position provider
* Add configmap-based log position provider
* Rename githubwebhookdeliveryforwarder to hookdeliveryforwarder
* Refactor to rename LogPositionProvider to Checkpointer and extract ConfigMap checkpointer into a dedicated pkg
* Refactor to extract logger initialization
* Add hookdeliveryforwarder README and bump go-github to unreleased ver
* feat: HorizontalRunnerAutoscaler Webhook server
This introduces a Webhook server that responds GitHub `check_run`, `pull_request`, and `push` events by scaling up matched HorizontalRunnerAutoscaler by 1 replica. This allows you to immediately add "resource slack" for future GitHub Actions job runs, without waiting next sync period to add insufficient runners.
This feature is highly inspired by https://github.com/philips-labs/terraform-aws-github-runner. terraform-aws-github-runner can manage one set of runners per deployment, where actions-runner-controller with this feature can manage as many sets of runners as you declare with HorizontalRunnerAutoscaler and RunnerDeployment pairs.
On each GitHub event received, the webhook server queries repository-wide and organizational runners from the cluster and searches for the single target to scale up. The webhook server tries to match HorizontalRunnerAutoscaler.Spec.ScaleUpTriggers[].GitHubEvent.[CheckRun|Push|PullRequest] against the event and if it finds only one HRA, it is the scale target. If none or two or more targets are found for repository-wide runners, it does the same on organizational runners.
Changes:
* Fix integration test
* Update manifests
* chart: Add support for github webhook server
* dockerfile: Include github-webhook-server binary
* Do not import unversioned go-github
* Update README
Patrick Ellis
Yusuke Kuoka